Preharvest Planning and Winery Sanitation

By Molly Kelly, Enology Extension Educator

The Preharvest Planning and Winery Sanitation webinar from July 29th, 2020 is summarized below.

Preharvest Planning

Harvest is fast approaching, ready or not. With some careful planning, harvest does not have to be chaotic. Now is the time to go back and look at the 2019 harvest and identify areas needing improvement. You should also have a plan for each lot of grapes and have responsibilities for each employee clearly defined.

Now is also a good time to inspect the winery. Clean up clutter and determine what needs replaced. Resolve any pest issues and check the refrigeration system. Is the water quality adequate? If not get it serviced now. For worker safety, install CO2 sensors if you do not have them already.

If you are purchasing fruit, have all contracts in place. Have the grower provide a crop estimate so that you can plan accordingly. Request berry parameters (Brix, pH, TA) be sent regularly as harvest approaches. Also confirm if the fruit will be delivered to your winery or picked up. Visit the vineyard regularly and be sure to convey expectations. Examine all fruit for ripeness and any rot or insects present.

In preparation for crush, consider three main areas: the crush pad, fermentation cellar and barrel room. Within each of these areas, pre-crush tasks can be divided into four areas: planning, corrective maintenance, preventative maintenance and lastly sanitation. Of this list, sanitation is definitely of high importance.

While planning, consider a baseline work-flow for receiving, crushing, pressing and fermenting the grapes. Start with a basic white and a basic red plan. You can add more details as harvest goes on. This also allows new employees or harvest interns to know what to expect next in the process. I also recommend a HACCP plan (Hazard Analysis and Critical Control Points). This involves looking at the production process from start to finish. This can be in a flow-chart format. You then identify where hazards can occur and put in controls and monitor them routinely. For example, at the end of fermentation measure the volatile acidity, have an acceptable level, list how to address if too high. Continue to monitor throughout the winemaking process and keep good records.

Make sure to know approximate harvest yields and determine the tank/barrel capacity needed. For whites you will need 210 gallons of tank space per ton of fruit. Red fermentations on the skins will need 250 gallons per ton. Storage gallons for both will be approximately 165 gallons per ton.

In the winery, have your cooling system checked, inventory barrels and identify leakers. All equipment should be tested including scales, crusher/destemmer, pumps, press, and forklift several weeks before harvest. Remember to inventory all wine. What do you still have an abundance of in inventory? Maybe it is time to re-evaluate plans to produce those wines this harvest.

On the crush pad, make sure that bins are cleaned. Know where grapes will be stored, if needed, when they arrive. Do you need to arrange for a refrigerated truck rental? In addition, have a plan for how pomace will be disposed. It is imperative that pomace be as far away from the winery as possible. You will certainly have a fruit fly infestation if it is close to the winery.

This is by no means a complete list but please refer to the list below of common chemicals and supplies that you may need.

  • Yeast
  • Sulfur dioxide (potassium metabisulfite)
  • Acids (tartaric, citric)
  • Rice and yeast hulls
  • Enzymes
  • Tannins
  • Gas cylinders
  • Lysozyme?
  • Sugar
  • ML culture
  • Yeast nutrients
  • Diammonium phosphate or other N source
  • Fining agents (bentonite, isinglass, PVPP)
  • Filter pads (stacked pad, sterile cartridge)
  • Cleaning supplies

Don’t forget to order lab supplies if you will be performing tests in-house. If you will be sending samples to a reference lab, have enough sample containers, labels and shipping boxes on hand. Some basic things that you may be measuring include:

  • YAN
  • pH-replace probe every 2 years or as needed
  • TA
  • Brix-have extra hydrometers on hand
  • SO2
  • VA
  • MLF
  • Alcohol

 

Some additional equipment considerations:

  • Check all equipment is in functioning order and service if needed
  • Do you need to rent an extra forklift?
  • Do you have an extra pump/press on hand?
  • I recommend going through a dry run to ensure that you haven’t missed anything
  • Clean and sanitize everything
  • Know your neighbors. Can you ask to borrow supplies if needed?
  • Have spare parts on hand for minor repairs

Consider staffing needs. Have standard operating procedures (SOPs) for everything to make sure that each protocol is being done exactly the same by all employees and provide necessary training. Have personal protective equipment (PPE) on hand to provide a safe work environment. Material safety data sheets (MSDS) should be available for every chemical in the winery. Information contained in the MSDS includes precautions to be taken when using a chemical and what to do in case of exposure.

With the current coronavirus pandemic, make sure to comply with all state and federal regulations. Check the CDC guidelines for manufacturing workers  (includes food processing facilities) and PA guidance for businesses for the most up-to-date COVID information. Be sure to train all employees in COVID regulations and safety training. You probably have many of these in place for tasting rooms.

 

Winery Sanitation

Proper winery sanitation is absolutely the most important aspect in quality wine production. Wine is an acid food (low pH). This combined with the ethanol that it contains makes wine unable to support the growth of human pathogens. According to the Federal Drug Administration (FDA), a winery is a food processing facility and subject to federal regulations, especially Good Manufacturing Practices (GMPs) listed in Title 21 CFR 110.These regulations include sanitation and processing requirements for the production of safe food.

First, we will introduce some definitions used in a sanitation program: cleaning, sanitizing and sterilizing. Knowing the differences among these will enable a winery to implement a more effective sanitation plan.

Cleaning: Removing of mineral of organic matter, and debris from surfaces (normally using detergents). This step also eliminates environments conducive to growth of spoilage organisms.

Sanitizing: Reduction of the microbial population to a safe or acceptable level (kills 99.99%) of organisms. NOTE: You cannot sanitize a dirty surface!

Sterilizing: Provides 100% kill of viable cells including spores.

General steps in cleaning and sanitizing include:

  1. Removal of debris without water. This may include removal of rachises and leaves from the crusher/destemmer missed last year.
  2. Pre-rinse to remove some organic debris that is not tightly bound.
  3. Use of detergent, usually alkaline in nature. This will remove organic material such as proteins.
  4. Rinse
  5. Use of a sanitizer, usually acidic in nature. This will remove inorganic matter such as metallic residues and alkaline residues not removed during cleaning with detergent.
  6. Rinse (may not be needed with certain sanitizers)

 

Some areas/sources that are prone to build-up of spoilage organisms include:

  • The vineyard: fruit may come in from the vineyard with rot or insects
  • Diluted pools of juice on the crush pad or in the winery
  • Second-hand barrels: know your source
  • Imported bulk wine
  • Areas of the winery that are difficult to reach
  • Fruit flies: capable of carrying spoilage organisms throughout the winery
  • Wine thief: sanitize or sterilize between each barrel using 70% alcohol. A presentation from Cornell included the suggestion that a thermos with >185F water would result in an instant kill of organisms when thief was dipped between barrels.

There are a number of factors involved in determining how likely it is for spoilage organisms to thrive including:

  • Oxygen: acetic acid bacteria and others grow best in the presence of oxygen
  • Temperature: the warmer the temperature (to a certain point) encourage organisms to grow. Lower temperatures inhibit their growth.
  • Alcohol: the higher the alcohol, the greater the inhibition of organisms
  • Molecular SO2: this is the free form of SO2 that is the antimicrobial form
  • pH: the lower the pH the less chance of microbial growth. As pH approaches 4.0, the greater the chance of microbial growth.
  • Nutrient status: if there is a nutrient source present, other spoilage organisms can grow

Some of the microbes that may grow during fermentation include non-Saccharomyces yeasts, lactic acid bacteria and acetic acid bacteria. In order to detect the presence of these organisms, you should monitor for the following:

  • Ethyl acetate
  • Spontaneous or sluggish fermentation
  • Spontaneous malolactic fermentation
  • Volatile acidity
  • 4-ethyl phenol and 4-ethyl guaiacol
  • Sulfur-like off odors
  • Other off odors

As a rule of thumb, acid cleaners dissolve alkaline soils (minerals). Alkaline cleaners dissolve acidic soils and food wastes (proteins). The improper use of detergents can actually “set” soils, making them more difficult to remove (e.g. acid cleaners can precipitate proteins).

It is a common misconception that “if a little is good, more is better”. Using sanitizer concentrations above recommendations does not make sanitizer perform better. In fact, this can corrode equipment. Always follow manufacturer label instructions.

 

Cleaners

Prior to using detergents to clean, apply a warm (100-109F), high pressure rinse (600-1200 psi). Avoid the use of hot water that can “bake on” debris. Once the visible debris is removed, detergents are used to solubilize remaining deposits. Detergents include alkalies, acids, surfactants and rinses.

Alkalies are excellent detergents and include caustic soda (NaOH) and caustic potash in the pH range of 12.0 to 14.0. They work well on tartrates and have strong antimicrobial properties. Care must be taken when using them including the use of proper personal protective equipment (PPE). If used too concentrated, they will corrode stainless steel. There are milder alternatives such as sodium carbonate (soda ash) or trisodium phosphate (TSP) in the pH range of 10.0-11.5. The alkaline compounds kill cells by stripping the cell membrane of yeast and bacteria.

Acid detergents reduce mineral deposits and also soften water. The pH is between 1.5 and 3.5. These can also be corrosive to metals such as stainless steel. An example is phosphoric acid.

Surfactants lower the surface tension between a liquid (water containing detergent) and a solid (debris) making the dirt more soluble and easier to remove.  One end of the surfactant is hydrophilic (water-loving) and the other end hydrophobic (water-repelling).

After cleaning with detergents, a rinse may be required. For example, a mild acid rinse (citric) can be used to neutralize alkaline residues.

 

Sanitizers

Once thoroughly clean, a surface can then be sanitized. Sanitizers work by lysing cell membranes, blocking membrane functions (e.g. waste removal) and inactivating key enzymes. There are some combined cleaner/sanitizers but a sanitation step is still required. It is vital to make sure the surface is clean since sanitizers will preferentially bind to organic matter.

Some examples are listed below and their use briefly discussed:

  • Acidulated sulfur dioxide
  • Halogens
  • Quaternary ammonium compounds (QUATS)
  • Iodine
  • Hot water and steam
  • Peroxides
  • Peracetic/hydrogen peroxide
  • Ozone
  • Ethanol (70%)/80 proof vodka

 

Acidulated sulfur dioxide

This sanitizer has antimicrobial activity which is pH dependent (3.0-4.0). In acidulated cold water (pH below 3.5) more SO2 will be in the molecular form. Use 100 ppm SO2 (200 ppm potassium metabisulfite and 3 g/L citric acid, or enough to achieve a pH below 3.5). It is good for sanitizing hoses and in closed systems.

 

Halogens

Chlorine-containing (sodium and calcium hypochlorite) compounds are halogens and are not recommended except for out of control microbial situations. They act as precursors in the microbial formation of trichloroanisoles (TCA). Chlorine dioxide is a broad-spectrum antimicrobial and is effective in destroying biofilms. Chlorine is not a by-product therefore TCA is not a concern.

 

Iodine

The iodophors also have a broad spectrum of activity against microorganisms. At a concentration of 25 ppm, pH<4.0 it is active against bacteria, viruses, yeasts and molds. Iodine can be used to sanitize bottling lines followed by a cold rinse. There may be the potential for formation of TCA.

 

Quaternary ammonium compounds (QUATS)

QUATS are a cationic (positively charged) surfactant. At a concentration of 200 ppm they damage cell membranes of microorganisms (lactic acid bacteria more so than acetic acid bacteria). They leave a residual antimicrobial film if unrinsed. They can be used on floors and walls and other non-product contact areas.

 

Hot water and Steam

Hot water and steam are strong antimicrobials at >180F for no less than 20 minutes. They may degrade gaskets but are non-corrosive. Their main use is the sterilization of bottling lines and for barrel sanitation (140-176F using high pressure). At temperatures between 170F and 185F, there is an instant kill of microorganisms.

 

Peroxides

Hydrogen peroxide breaks down to superoxide oxygen (O2). Peroxides are very effective antimicrobials but less so against spores and wild yeasts. Peroxyacetic acid (PAA) combines peracetic acid and hydrogen peroxide that work synergistically to kill 99.99% of microbes. At the diluted concentrations (2.5-15%) it leaves low residual PAA (3-5 ppm), requiring no rinse. A strong oxidizer, PAA can be used to sanitize many surfaces including barrels and bottling line sanitation. Concentrated solutions are corrosive, but diluted, it is also environmentally friendly, breaking down to acetic acid, water and oxygen.

 

Percarbonates and Soda ash (sodium carbonate)

Per(oxy)carbonates are a stabilized powder with hydrogen peroxide. Oxygen radicals are released via hydrogen peroxide. This alkaline product degrades to soda ash, water and oxygen. It is commonly used on barrels but, due to their porous nature, 100% kill is not achieved.

Soda ash is a strong alkaline compound. It dissolves proteins, fats, oils and carbohydrates. It also works well on tartrates. It can also neutralize odors associated with volatile acidity.

 

Ozone (O3)

Ozone is a potent sanitizer but is not a cleaner. It is a hyper-radical of oxygen that has strong oxidizing properties. It can be dissolved in water or applied as a gas. It has a shorter half-life in water (seconds) compared to gas (24 hours). If water is used, it must be generated on demand by exposing a stream of dry air to an electrical discharge. It is active against bacteria, fungi and spores. Be sure to check gasket compatibility as ozone can degrade certain ones. Ozone is a strong irritant so train staff and have proper safety monitors in place.

For barrels, the following protocol is suggested:

  • Perform high pressure cold wash
  • Follow with hot water or steam
  • Cool rinse 2-3 minutes
  • Rinse with ozonated water (filtered water since minerals limit ozone effectiveness)
  • Follow manufacturer’s suggested contact time/concentration

 

Other

Additional sanitizing options include:

  • UV light
  • Dry ice blasting for barrels
  • High power ultrasound for barrels

 

Hoses, valves and fittings

When sanitizing fittings, consider soaking in a solution. For example, an alkaline cleaner followed by a citric acid rinse to neutralize. Then apply acidulated sulfur dioxide to sanitize.

Tygon® corrugated hoses (you can see through them) are recommended. Rubber/fiber blend hoses are harder to clean and not transparent. Consider the use of foam balls to better clean hoses.

Ball valves tend to harbor more debris and microbial growth compared to butterfly valves. Take all valves apart and clean/sanitize prior to harvest. I suggest filling the tank with water when valves are replaced to make sure they don’t leak. Gaskets may need to be replaced and can be easily made with a gasket kit (use food grade rubber).

 

Drains and Filters

Drains can be plugged and filled with sanitizer or hot water. I have found that peroxycarbonates followed by a citric rinse to also work well.

If you choose to reuse filters, you can use a caustic/acid treatment followed by a sanitizing step. Rinse with a sanitizer before use (e.g. KMS/citric). Remember to perform an integrity test (e.g. bubble point) prior to filter use.

 

Barrels

Care must be taken when treating barrels as chemicals can either taint the wood or extract essence.

Some considerations for barrels:

  • Don’t let them dry out
  • Store with KMS/citric acid solution
  • Clean the outside as well as the inside
  • Recover with a percarbonate based cleaner (1 T/gal), let sit 24 hrs., rinse, rinse again with citric acid (0.5 t/gal)

 

Rotating Schedule

Cleaners and sanitizers should be rotated every 1-2 weeks. For example, four days a week use a caustic detergent to clean (alkaline) followed by peroxyacetic acid sanitizer. The fifth day, use an acid cleaner to decrease mineral deposits. This will also remove deposits not removed by the alkaline cleaner. Then apply an appropriate sanitizer.

 

Biofilms

Some microbes use nutrients from juice and wine to form polymers. Once on a surface, other bacteria will aggregate and attach. They continue to grow, forming a biofilm with a protective layer surrounding the microbes. Invisible to the naked eye, biofilms are resistant to many chemical cleaners. They usually need physical action (scrubbing, high pressure) for removal.

One suggested treatment is the use of caustics (167F for 30 min.) followed by a citric acid rinse. Ozone has been shown to be ineffective in treating biofilms.

 

Sterilizers

In the winery, we typically do not achieve true sterility. Rather, we reserve “sterilization” steps for processes such as sterilization of the bottling line.

Hot water and steam are normally used:

  • 180F for 20-30 min.
  • Ozone for 20-30 min.

Sources of contamination at bottling include:

  • Filler bowls: use steam or hot water (180-185F) to “sterilize”
    • Thermal dots on the outside of filler bowl can verify temperature
  • Mist filler spouts with 70% ethanol to inhibit microbial growth
  • Corker: likely to have spilled wine present. Mist jaws with ethanol during bottling.
  • Activity: limit number of people in the area

 

Verification

  • Strips are available to test concentration of sanitizers
  • Verify contact time by using a timer
  • Verify proper temperature of solutions
  • Areas of the winery can be swabbed and plated on agar growth media or sent to a reference lab for culture and/or molecular testing
  • Photodetectors using bioluminescence technology can be used to monitor presence of cellular material. Surfaces are swabbed and if ATP is present (energy-carrying molecule found in all living things), in the presence of luciferin and an enzyme, it will fluoresce. The degree of fluorescence is proportional to the number of cells present.

 

Basic Rules

  • Clean then sanitize everything prior to use
  • Clean everything after use
  • Keep the winery premises clean and clutter-free
  • Monitor for mold, bacteria, rodents etc.
  • Deal with pomace immediately

Remember that winery sanitation will impact final wine quality. Clean, then sanitize!

 

References

  • Butzke, C., Barrel Maintenance, Dept. of Food Science, Purdue University, 2007.
  • Crowe, A. Avoiding Stuck Ferments, Wine Business Monthly, August 2007.
  • Dharmadhikari, Murli. “Harvest Preparation.” Vineyard & Vintage View 6, no. 7 (1991): 1.
  • Howe, P., ETS Laboratories, SOWI “Current Issues” Workshops March 2011.
  • Just, E. and H. Regnery. Microbiology and Wine Preventive care and monitoring in the wine industry. Sartorius Stedim Biotech. 2008.
  • Lansing, R. May 2011. Managing Bottling Operations. Wine Business Monthly.
  • Margalit, Y., Winery Technology and Operations, The Wine Appreciation Guild, San Francisco, 1996.
  • Menke, S., Cleansers and Sanitizers, Penn State Enology Extension, 2007.
  • Neradt, F. 1982. Sources of reinfections during cold-sterile bottling of wine. Am. J. Enol. Vitic. Vol. 33. no. 3.
  • Pregler, B. Dec 2009. What’s Cool: Accurate Membrane Filter Integrity Testing. Wine Business Monthly.
  • Ritchie, G., Napa Valley College, VWT 280, Cellar Hygiene, 2007.
  • Tracy, R. and Skaalen, B. Jan/Feb 2009. Bottling-last line of microbial defense. Practical Winery and Vineyard.
  • Van de Water, L., Practical Winery and Vineyard Journal, Sept/Oct 2009.
  • Worobo, R. June 2012 Northern Grapes Project Webinar “Introduction to Winery Sanitation: Options to Applications.
  • Zoecklein, B. et al, Wine Analysis and Production, Aspen Publishers, 1999.
  • Zoecklein, B., HACCP-Like Plans, Enology Notes #115, Virginia Tech, August 2006.

 

 

 

Why, When, and How to Measure YAN

by Molly Kelly, Enology Extension Educator

By managing fermentation, winemakers today have many options to enhance the varietal characteristics of their wines, and to express regional attributes. Winemakers know that temperature is a management tool that affects the rate of fermentation; similarly, the presence of grape solids enhance yeast survival. Very importantly, adequate nitrogen (N) is necessary for a successful fermentation.

Grapes contain a variety of nitrogenous compounds, the sum of which may be affected by viticultural practices. For instance, research has demonstrated that N concentration is 2X greater with application of foliar N and appropriate irrigation use than without foliar N and irrigation. Other research suggests that   N application around veraison appears to be an effective way increasing N in the fruit, regardless of water-supply status of the vines. The concentration of nutrients, whether too great or too little, can induce stress and lead to different concentrations of flavor compounds. For instance, H2S formation is a well-known example related to inadequate nutrients leading to nitrogen depletion stress.

A common practice among winemakers is to make a standard addition of diammonium phosphate (DAP), or other N source, to the juice or must (100-300 mg/L) at inoculation without measuring the nitrogen concentration. The objective of this article is to show that N addition has significant flavor (and ultimately, economic) consequences and that measuring the initial nitrogen concentration provides the opportunity to adjust N addition – not only to achieve an adequate fermentation rate, but also to more  reliably guide the flavor profile and style of wine intended.

 

Definition and Measurement of “YAN”

Grapes contain a variety of nitrogenous compounds of which the most important are the primary (alpha) amino acids, ammonium ions, and small peptides. These three nitrogenous compounds – amino acids (excluding proline), ammonium ions, and small peptides – constitute what is commonly referred to as yeast assimilable nitrogen (YAN) or fermentable nitrogen.

YAN measurements, ideally, should be performed directly on juice or must samples at the point of inoculation to avoid over-estimation due to processing losses which inevitably occur between vineyard and the fermenter. Juice samples taken from grape musts can under-estimate total berry YAN due to the disproportionate concentration of amino acids contained in the unsampled grape skins. While an early warning for low YAN may be obtained by sampling in the vineyard one to two weeks prior to harvest, measurement immediately before fermentation is necessary due to the highly variable nature of YAN measurements during those last weeks before harvest.

Favored methods of measurement of YAN are (a) enzymatic assay kits, (b) the method known as the Formol Titration, which consists of neutralizing a juice sample with a base, then adding an excess of neutralized formaldehyde, and re-titrating the resulting solution to an endpoint; and (c) use of expensive equipment such as the HPLC (high-performance liquid chromatography). Typically, wineries use the first two methods; commercial labs may use the third method.

 

How much YAN

YAN has the most impact on fermentation speed compared to other compounds. It impacts yeast biomass at the beginning of fermentation and sugar transport during fermentation. At the end of growth phase, N is depleted resulting in decreased protein synthesis and sugar transport. A YAN addition at this point reactivates protein synthesis and sugar transport increasing the fermentation rate. Oxygen is rapidly consumed in the beginning of fermentation. Decreased oxygen inhibits sterols and fatty acid synthesis by yeast. This causes decreased yeast growth and viability at the end of fermentation.

Sterols and fatty acids are survival factors needed for the yeast cell membrane to function. As ethanol increases, hydrogen ions accumulate in cell requiring more energy to expel them. The pH decreases inside the cell causing cell death. Oxygen adds at end of growth phase increase sterol production. Therefore, microoxygenation and pump overs would be beneficial at 1/3 of the way through alcoholic fermentation (end of yeast growth phase).

Saccharomyces

Budding Saccharomyces cerevisiae       photo by Molly Kelly

N assimilation

The manner in which N is assimilated by yeast depends on the source. Organic N (amino acids) is actively transported into the yeast cell. Through additional reactions N is incorporated into glutamine and glutamate and eventually used in the synthesis of other amino acids and nitrogenous compounds. This process is gradual and efficient compared to inorganic sources. Ammonium nitrogen (inorganic N) is consumed quickly and is less beneficial. Amino acid mixtures vs single N sources are more efficient because the yeast directly incorporates the amino acids into proteins rather than having to synthesize them.

Ammonia, which exists as ammonium (NH4+) ions in must, is used by yeasts prior to amino acids. The presence of NH4+ delays timing and uptake of amino acids by yeast.

The timing of N supplements and form of supplement will impact fermentation and volatiles. Types of N supplements include Diammonium phosphate (DAP), proprietary blends of DAP and amino acids (e.g. Superfood®, Fermaid K®, Actiferm) and balanced nutritional formulas containing inorganic N (e.g. Fermaid O®), organic N, sterols, yeast cell walls, fatty acids, yeast autolysis products and others. DAP is best used with low N musts. Other balanced nutrients should be added as well. At a rate of 100 mg/L DAP, 20 mg/L YAN is added.

It is common practice for winemakers to make N additions at the following times:

  • Yeast rehydration to rebuild cell walls (rehydration nutrients consist of inactivated yeast and autolysates. They contain no inorganic N and only 3 mg/L N for every 100 mg/L added).
  • Six-twelve hours after inoculation (2-3 Brix drop)
  • End of growth/exponential phase (1/3 sugar depletion)
yeast growth curve

Yeast Growth throughout Fermentation

Note that at ½ sugar depletion the yeast cannot utilize N since alcohol accumulation prevents uptake. This residual N can then be utilized by other organisms such as Brettanomyces spp.

 

Results of Deficient YAN

From a practical point of view, the problem of juice nitrogen composition is primarily linked to juices with suboptimal concentrations of nitrogen (<150 mg/L), and higher risk of slow or stuck fermentation. Low YAN (< 200 mg/L) is associated with production of sulfur compounds, e.g. hydrogen sulfide, which results from the nitrogen demand for yeast growth. The amount of H2S produced is dependent on the yeast strain, the sulfur precursor compound, the culture growth rate, and the enzymatic activity immediately before nitrogen depletion.

When working with very low YAN juices, researchers have observed that other nutrients can also be low. Therefore, when YAN is low and other nutrient deficiencies are suspected, it may be useful to add a proprietary yeast food that contains more complex forms of N, as well as vitamins, lipids and minerals. Continued H2S production after N addition suggests a general vitamin deficiency, though other causes are also possible. Most yeast suppliers can advise on the use of yeast foods, which are generally produced from inactivated yeast, e.g. GoFerm® or similar additives.

In summary, low must YAN leads to low yeast populations and poor fermentation vigor, increased risk of sluggish/stuck/slow fermentations, increased production of undesirable thiols (e.g. hydrogen sulfide) and low production of favorable sensory compounds including esters and long chain volatile fatty acids.

 

Results of Excessive YAN

High must YAN leads to increased biomass and higher maximum heat output due to greater fermentation vigor. Overuse of DAP can also stimulate overproduction of acetate esters, especially ethyl acetate, resulting in the perception of volatile acidity (VA) and suppression of varietal character. High YAN (exceeding 450-500mg/L YAN) can stimulate ethyl acetate production by many yeast strains. Increased concentrations of haze-causing proteins, urea and ethyl carbamate and biogenic amines are also associated with high YAN musts. The risk of microbial instability, potential taint from Botrytis-infected fruit and possibly atypical aging character is also increased.

 

Main Flavor Changes Affected by Nitrogen

In general, YAN can affect TA and the balance of organic acids which can affect flavor. Malic acid consumption increases with increasing DAP concentration, irrespective of yeast strain. When total nitrogen is increased by adding ammonium to a medium containing very low levels of YAN, the production of higher alcohols is initially increased, but then tends to decrease after a peak between 200-300mg/L YAN. This activity depends on various factors, including yeast strain and fermentation conditions. Higher alcohols are characterized by fusel-like odors, and are generally thought to contribute to the complexity of wine fermentation bouquet. However, when present in very high concentrations they can have a negative impact on wine aroma, mainly because they mask fruity characters.

Of course, intermediate must YAN favors the best balance between desirable and undesirable chemical and sensory wine attributes. The key is to have timely and accurate YAN must concentration data immediately before primary inoculation. Recognizing that measurement is difficult in a winery setting, we encourage use of commercial and extension labs that offer YAN measurements, so that the winemaker might make an informed decision regarding supplemental nitrogen additions.

 

References

AWRI: Maurizio Ugliano, P. A. H., Markus J. Herderich, Isak S. Pretorius. 2007. Nitrogen management is critical for wine flavour and style. AWRI Report: The Australian Wine Research Institute, vol. 22. Wine Industry Journal, Glen Osmond (Adelaide), South Australia 5064, Australia.

Barthe, C., M. Dorais, G. Dubé, P. Angers, and K. Pedneault. 2013. Abstracts from Presentations at the ASEV–Eastern Section, 2013, Winston-Salem, NC. 64:417A.

Bell, S.-J., and P. A. Henschke. 2005. Implications of nitrogen nutrition for grapes, fermentation and wine. Australian Journal of Grape and Wine Research 11:242-295.

Blateyron, L. O.-J., A; Sablayrolles, J.M. 2003. Stuck fermentations: oxygen and nitrogen requirements – importance of optimising their addition. Aust. N.Z. Grapegrower Winemaker:73-79.

Cheng, L., T. Henick-Kling, A. Lakso, and T. Martinson. 2003. Abstracts, ASEV Eastern Section 27th Annual Meeting, 2002, Baltimore, MD. American Journal of Enology and Viticulture 54.

Henschke, P. A. 1996. Presented at the Eleventh international oenological symposium, Sopron, Hungary.

Henschke, P. A. J., V. 1993. Yeasts – metabolism of nitrogen compounds, p. 77-164. In G. H. Fleet (ed.), Wine Microbiology and Biotechnology. Harwood Academic Publishers, Chur, Switzerland.

Leonardelli, Michael J. Enology News & Notes, Volume 3, #2, ICCVE, U of Missouri, Fall/Winter 2013-2014

Moundtop.com. 2011. Estimation of Yeast Assimilable Nitrogen using the Formol Titration Technique, p. 3. Version 1.1 ed. http://www.moundtop.com.

Ribereau-Gayon, J. D., D.; Doneche, B.; Lonvaud, A. 2000. Handbook of Enology, Volume 1: The microbiology of wines and vinification, vol. John Wiley & Sons Ltd:, Chichester, UK.

Kelly, M., G. Giese and B. Zoecklein. Abstracts, Poster Session, Nitrogen Symposium, ASEV 66th National Conference, 2015, Portland, OR.

 

 

 

COVID-19 Federal Guidelines for Reopening Tasting Rooms (Part 3)

by Molly Kelly, Enology Extension Educator

In blog post #1 (June 29th) Penn State Extension covered current COVID-19 state guidelines for the reopening of Pennsylvania tasting rooms. In the second post (July 13th) we covered federal guidelines of general best practices related to the reopening of tasting rooms and COVID-19 drawn from guidance by the Centers for Disease Control (CDC), US Department of Labor, American Industrial Hygiene Association (AIHA), Occupational Safety and Health Administration (OSHA) and the Food and Drug Administration (FDA).

These agencies offer considerations for ways in which operators can protect employees, customers, and communities and slow the spread of COVID-19. These considerations are meant to supplement—not replace—any state, local, territorial, or tribal health and safety laws, rules, and regulations with which businesses must comply.

In this third and final post we will discuss additional federal guidelines to more safely open tasting rooms.

Ventilation

  • Make sure ventilation systems are operating properly and increase circulation of outdoor air as much as possible (ex: open windows/doors, prioritize outdoor seating).
  • Do not open windows/doors if doing so poses a safety or health risk (ex: fall risk, triggering asthma attacks).
  • Maintain indoor relative humidity at 40-60%.
  • Consider using portable HEPA filtration units.
  • If fans such as pedestal fans or hard mounted fans are used in the bar, take steps to minimize air from fans blowing from one person directly at another individual.

NOTE: Contact an occupational health and safety professional or ventilation specialist for advice on how to best utilize ventilation systems.

Signs and Messages

  • Post signs in highly visible locations (ex: restrooms, entrances) that promote everyday protective measures (ex: proper handwashing, wearing masks).
  • Place signs at the entrance that encourages customers to follow physical distancing requirements. Find creative and fun ways for staff and security to encourage customers to follow these guidelines.
  • Place signs asking customer and employees to wash hands before and after using the restroom.
  • Refer to CDC’s free print and digital resources.

Promoting Behaviors that Reduce Spread/Protect Employee Health

  • Stay home when appropriate.
  • Develop policies that encourage sick employees to stay home.
  • Employees should stay home if they have tested positive for or are showing COVID-19 symptoms.
  • Employees who have recently had a close contact with a person with COVID-19 should stay home and monitor health.
  • Stagger or rotate shifts to limit number of employees present at same time.
  • Minimize the number of customers present at one time (refer to previous post for PA-specific guidelines).
  • Designate a COVID-19 Point of Contact for each shift to be responsible for responding to COVID concerns.

Establish protocols for execution upon discovery that the business has been exposed to a person who is a probable or confirmed case of COVID-19 including:

  • Close off areas visited by the person who is a probable or confirmed case. Open outside doors and windows and wait a minimum of 24 hours, or as long as practical, before beginning cleaning and disinfection. Ensure safe and correct use and storage of EPA-approved List N disinfectants.
  • Prepare to isolate and safely transport those who are sick to their home or a healthcare facility.
  • Identify employees that were in close contact (within about 6 feet for about 10 minutes) with a person with a probable or confirmed case of COVID-19 from the period 48 hrs before symptom onset to the time at which the patient isolated. Advise them to stay home and self-monitor for symptoms and follow CDC guidance if symptoms develop.
  • Consistent with applicable law and privacy policies, have staff self-report to the designated Point of Contact if they have symptoms of COVID-19 or were exposed to someone with the virus within the last 14 days.
  • Close off areas used by a sick person. Wait at least 24 hours before cleaning and disinfecting.
  • Notify local health officials of any case of COVID-19 while maintaining confidentiality in accordance with the Americans with Disabilities Act (ADA).

Communication

  • Communicate to the customers what the bar is doing to mitigate the spread of COVID-19 (e.g., disinfection routine, health policies for staff, and health & safety measures in place).
  • Consider placing signage on tables to show that they have been disinfected after previous customers.
  • Communicate that the bar has the right to refuse service to anyone exhibiting      symptoms or not following guidelines (ex: physical distancing).
  • Platforms for communication could include websites, reservation processes, hand-outs, and outdoor signage.

 

Disclaimer: Penn State Extension educational programs, content, and recommendations (including text, graphics, and images) are for educational purposes only. The Pennsylvania State University does not guarantee the accuracy, adequacy or completeness of any information and is not responsible for any errors or omissions or for the results obtained from the use of such information.

 

References

 

 

Correction

Please note that the “HANDWASHING” section of today’s blog post “COVID-19 Federal Guidelines for Reopening Tasting Rooms”should state that hands should be washed for 20 seconds, not 20 minutes!

I apologize for the miscommunication.

COVID-19 Federal Guidelines for Reopening Tasting Rooms

by Molly Kelly, Enology Extension Educator

In blog post #1 (June 29th) Penn State Extension covered current COVID-19 state guidelines for the reopening of Pennsylvania tasting rooms. In the second and third post we will cover federal guidelines of general best practices related to the reopening of tasting rooms and COVID-19 drawn from guidance by the Centers for Disease Control (CDC), US Department of Labor, American Industrial Hygiene Association (AIHA), Occupational Safety and Health Administration (OSHA) and the Food and Drug Administration (FDA).

These agencies offer considerations for ways in which operators can protect employees, customers, and communities and slow the spread of COVID-19. These considerations are meant to supplement—not replace—any state, local, territorial, or tribal health and safety laws, rules, and regulations with which businesses must comply.

Cleaning and Disinfection

  • Continue to follow all required state and local regulations (see June 29th post)
  • Cleaners, Sanitizers and Disinfectants defined:
    • Cleaners remove dirt and debris by scrubbing, washing and rinsing. Be sure you are using the right type of cleaner for the soil you need to remove.
    • Sanitizers kill certain bacteria (listed on product’s label), in a specific period of time, and are regulated by the EPA.
    • Disinfectants kill certain bacteria, viruses, mildews, or fungi (listed on se products that meet EPA disinfection criteria (List N) and that are appropriate for the surface. Note contact time according to manufacturer directions.
  • Clean and disinfect high touch areas routinely in accordance with guidelines issued by the Centers for Disease Control and Prevention (CDC). Maintain pre-existing cleaning protocols established by the business for all other areas of the building.
  • Establish disinfection protocols and train staff on proper cleaning/disinfection.
  • Consider establishing a single staff position whose responsibility is to disinfect. This person should be continuously cleaning and visible to customers.
  • Consider using a checklist or audit system to track how often cleaning is conducted.
  • Wear gloves to empty garbage cans. Wash hands after removing gloves (see link for poster showing correct removal of gloves)

General cleaning and disinfection practices (CDC).

  • Remove visible dirt and debris.Routinely clean surfaces and objects with soap and water.
  • Disinfect with EPA-approved products.
  • If these products are not available, alternative disinfectants may be used (ex: 1/3 cup bleach added to 1 gallon of water, or 70% alcohol solution).
  • Frequently touched surfaces should be cleaned and disinfected at least daily.
  • Adjust your practices as federal, state and local guidance are updated.
  • If your business has been unoccupied for more than 7 days, it will only need your normal cleaning routine to reopen since the virus cannot survive on surfaces longer than this time.
  • Soft and porous materials that are not frequently touched should only be cleaned or laundered following label directions, using the warmest appropriate water setting.
  • Regularly disinfect liquor bottles, pour stations, taps, etc.

 Restrooms

  • Doors to multi-stall restrooms should be able to be opened and closed without touching handles, if at all possible.
  • Place a trash can by the door if the door cannot be opened without touching the handle.
  • For single restrooms, provide signage and materials (paper towels and trash cans) for individuals to use without touching the handles.
  • Provide paper towels and air dryers in restrooms.
    • The WHO and CDC currently state that hands can be dried using a paper towel or hand dryer.
    • The use of touch or push hand dryers is discouraged due to possible surface contamination. If hand dryers are used, consider touchless devices.

Handwashing

  • Require frequent handwashing for at least 20 seconds with soap and water.
  • Establish a “before and after service” hand washing or sanitizing for all staff including bar staff.
  • Provide hand sanitizer at each table and throughout the bar.
  • Although not necessary if hand-washing protocols are rigorously followed, consider providing gloves to servers.  If they are worn, they must be changed regularly and are not a substitution for hand-washing.

Tastings

  • Ensure that all employees are made aware of required procedures by communicating them either orally or in writing.
  • COVID-19 transmission risk is highest during tastings when customers remove masks.
  • Masks should only be removed when tasting/eating and worn at all other times.
  • Since spitting increases aerosols, do not allow spitting.
  • Install physical barriers, such as sneeze guards and partitions, particularly in areas where it is difficult for individuals to remain at least 6 feet apart. Barriers can be useful at cash registers, tasting bar, host stands, or food pickup areas where maintaining physical distance of at least 6 feet is difficult.
  • Provide physical guides, such as tape on floors or sidewalks and signage, to ensure that individuals remain at least 6 feet apart. Consider providing these guides where lines form and at the bar.
  • Staff should pour samples 6 feet away from customers, place samples on bar/table and move 6 feet away or consider delivering samples to customers seated at tables.
  • No shared snacks such as crackers. Consider single serve containers.
  • Everything should be disposable. Glasses can be washed according to established protocols.
  • Use disposable cups if possible.
  • Prior to entering the tasting room, have customers confirm that they will abide by established protocols (ex: 6 feet distancing, masks).
  • Provide hand sanitizer throughout the business, including entrances and exits.
  • Consider starting with a “reservation only policy” to start.
  • Require face coverings for staff. The type depends on local requirements and availability.

Modified Layouts and Procedures

  • Alter layouts to ensure all customer parties remain at least 6 feet apart (ex: mark tables and chairs that are not to be used, tape on floors).
  • Ask customers to wait in their cars while waiting to be seated.
  • Inform customers of business policies on signs and website.
  • Use phone app/text or signs to let patrons know that table is ready.

Checkout

  • Discourage use of cash to make purchases.
  • Encourage credit card use over cash, when possible.
  • Have staff package purchases for customers.
  • Avoid lines and maintain 6 feet distancing.
  • Staff should wash or sanitize hands between transactions.

The third blog post will cover additional considerations for reopening tasting rooms.

 

Disclaimer: Penn State Extension educational programs, content, and recommendations (including text, graphics, and images) are for educational purposes only. The Pennsylvania State University does not guarantee the accuracy, adequacy or completeness of any information and is not responsible for any errors or omissions or for the results obtained from the use of such information.

 

References

 

 

Mid- to late-season insect and disease management in vineyards – webinar review

by Dr. Flor Acevedo, Assistant Professor of Entomology and Arthropod Ecology, Penn State Lake Erie Regional Grape Research and Extension Center; Andy Muza, Erie County / Penn State Extension Educator; and Bryan Hed, Plant Pathology Research Technologist, Penn State Lake Erie Regional Grape Research and Extension Center

On July 1, the authors presented Mid- to Late-Season Insect and Disease Management in Vineyards as part of the PSU Wine and Grape Team’s weekly webinar series.

Insect management.

This webinar covered the identification and management of main insect pests that may occur in vineyards in the Northeastern U.S. in mid to late season. Some of the insects covered were grape berry moth, grape leafhopper, Japanese beetle, grape phylloxera, brown marmorated stink bug, and fruit flies.  

  • Grape berry moth is a native species that cause direct damage to grape berries. It is one of the most important pests in grape in the Northeastern US. These insects overwinter as a pupa, moths emerge in spring and lay their eggs in the developing berries of wild grapes. The next generation of moths lay eggs into cultivated grapes, the larvae that hatch from those eggs feeds internally in grapes berries where is protected from insecticides. Therefore, effective control strategies need to be timed with insect development. Insect growth is highly correlated with temperature, consequently, the timing of sprays can be determined using the grape berry moth degree-day model available at (NEWA, http://newa.cornell.edu/index.php?page=grape-diseases).
  • Grape leafhoppers injure vine leaves by sucking out internal plant fluids. When populations are high, they can affect vine health and affect wine quality.
  • Japanese beetles are an invasive species that feed on leaves and can defoliate vines if their populations are high. 
  • Grape phylloxera is an aphid-like insect that has two forms, one that feeds on leaves and one that feeds on roots. Phylloxera has a very high reproductive capacity and is able to kill susceptible vines over a few years. The root form appears to be more aggressive than the leaf form. One of the best strategies to control phylloxera is the use of resistant rootstocks. 
  • Brown marmorated stink bug is an invasive species that feeds directly on grape berries, they are highly polyphagous feeding on reproductive structures of more than a 100 plant species. They can be a problem in vineyards if their populations are high, at harvest, they could contaminate the load and may affect the flavour of juice and wine.
  • Fruit flies could be an important pest at preharvest. Two main species are Drosophila melanogaster and spotted wing drosophila (Drosophila suzuki). Spotted wing drosophila is an invasive species native to south Asia and distributed in the Northeast in 2011. The large serrated ovipositors of spotted wing drosophila allow females to oviposit into intact ripe fruit. They are a major problem in berry crops. In grape they can be a problem in thin-skinned varieties grown for wine. In juice grapes they don’t appear to be a major problem. One of the main problems with fruit flies is their association with sour rot.

Here are links to presentations on mid- to late-season insect management in vineyards (by Flor and Andy):

Disease management.

This webinar covered the identification and management of diseases that occur in vineyards in the Northeastern U.S. in mid to late season, including: downy mildew, powdery mildew, sour rot, botrytis bunch rot, and ripe rot. Bryan recently wrote a blog post that covered mid- to late-season control of mildews and rots; to view that post, visit this link: https://psuwineandgrapes.wordpress.com/2020/06/24/mid-to-late-season-control-of-downy-and-powdery-mildew-and-bunch-and-sour-rots-in-2020/

Here is a link to the presentation on mid- to late-season disease management in vineyards (by Bryan):

Please contact any of the PSU Wine and Grape Team members if you have questions concerning viticulture, enology, and/or business and marketing. General inquiries can be sent to this email address: psuwineandgrapes@psu.edu

Best wishes for successful vineyard pest management between now and harvest!

Announcement

Please note that the LAFFORT webinar “Protecting Quality in a Challenging Harvest” has been changed from July 8th to July 22nd. Please see the attached pdf for more information and to register. If you registered for the July 8th webinar, you will need to register again.

Thank you.

Fungicide resistance management – webinar review

by Michelle Moyer, Viticulture Extension Specialist, Washington State University, and Cain Hickey, Viticulture Extension Educator, Penn State University

On June 24th, Dr. Michelle Moyer gave a webinar presentation entitled Fungicide Resistance and the Acronyms. In this webinar, Michelle discussed the nuances of managing fungicide resistance through judicious application of fungicides. Fungicide resistance management is optimized through good fungicide stewardship. Good fungicide stewardship includes rotating fungicide modes of action (within season and between seasons), timely application of  fungicides (before disease symptoms appear), using tank mixes that effectively and broadly manage a targeted fungal disease, and proper calibration and maintenance of spray application equipment to ensure adequate coverage of the target (grapevine canopy and/or clusters).

It is important to know that some fungicide classes are at greater risk of It is important to know that some fungicide classes are at greater risk of resistant development than others. For example, Fungicide Resistance Action Committee, or FRAC, code 7 (SDHI) and 11 (QoI)  fungicides are “high risk”, while FRAC code 3 (DMI) fungicides are currently considered “moderate risk”; but fungicide resistance to these classes have been found in several grape fungal pathogens. While good fungicide stewardship (see above for resistance management considerations) is important for all fungicides, it is important to be judicious when applying fungicide FRAC codes with moderate to high risk of resistance development. Please see Michelle’s slides for more information about fungicide resistance and its management:

Remember that chemical management of fungal diseases is only one part of an integrated management system. Cultural practices, such as canopy management and appropriate cultivar selection are also major contributing factors to a successful fungal disease management program.  

For additional information on fungicide resistance management in wine grapes, please visit: https://framenetworks.wsu.edu/ 

COVID-19 Guidelines for Reopening of Pennsylvania Tasting Rooms

by Molly Kelly, Enology Extension Educator

The virus that causes the Coronavirus 2019 Disease (COVID-19) is known as SARS-CoV-2. The virus can be easily transmitted, especially in settings where large groups gather. Penn State Extension offers the guidelines of health and safety best practices related to the reopening of tasting rooms to mitigate the spread of the virus. A series of general best practices was summarized through guidance from federal and state agencies including the Centers for Disease Control (CDC), US Department of Labor, American Industrial Hygiene Association (AIHA), Occupational Safety and Health Administration (OSHA), Food and Drug Administration (FDA) and the Pennsylvania Department of Health.

In this series of blog posts, we will first examine Pennsylvania-specific guidelines. Future posts will focus on federal guidelines. We will offer the most up-to-date information but please realize that guidelines may change quickly. In this post we offer some links that would be useful to check on a regular basis.

COVID-19 is mostly spread by respiratory droplets that are airborne when infected individuals cough, talk, or sneeze. The virus may also contaminate hands that touch surfaces with the virus present. It can then be spread to the nose or mouth, resulting in infection. A number of best practices are covered here  including handwashingstaying home when sick, and strict environmental cleaning and disinfection that can assist with lowering the risk of infection and viral spread. 

Pennsylvania is reopening counties in phases. As of June 20, 2020, all counties are in the green phase except one. Lebanon County remains in the yellow phase. Governor Tom Wolf announced that Lebanon County is slated to move to the green phase of reopening on July 3, putting all 67 counties in green. For  up to date information regarding phase status please see the official Pennsylvania government website at https://www.governor.pa.gov/process-to-reopen-pennsylvania/

Phases for Pennsylvania Counties

We also pulled those statements that we thought were most important to the industry. Please refer to the document above for detailed information.

  • Red: Businesses are permitted to provide take-out (curbside) and delivery sales only and may not allow the service or consumption of food or beverages on the premises. Also, masks are required.
  • Yellow: Businesses are permitted to provide take-out and delivery sales as well as dine-in service in outdoor seating areas as long as they strictly adhere to the state requirements for maximum occupancy limits (see below). Masks are required.
  • Green: Businesses are permitted to provide take-out and delivery sales as well as dine-in service in both indoor and outdoor seating areas as long as they strictly adhere to the state requirements including maximum occupancy limits. Masks are required.
  • Bar seating may be utilized provided that customers are seated and comply with the physical distancing guideline of at least 6 feet or physical barriers between customers.
  • A maximum of four customers that have a common relationship may sit together at the bar, while adhering to the physical distancing guidelines or barriers between other customers.
  • Penn State Extension suggestion:  Consider providing wine tasting at a table where the patrons are distanced from the pourer/server. That table can be better isolated and an establishment can serve more sets of patrons while avoiding a crowded bar.

 

State-specific and local guidance from the Pennsylvania Department of Health (updated June 25, 2020)

Please note that the COVID-19 situation is constantly changing and wineries are encouraged to follow updates.

The following items MUST be followed according to the order of the governor’s office:

  • Follow maximum occupancy limits for indoor/outdoor areas.
  • Method 1: Limit to 50% of state fire capacity or 24 people per 1,000 square feet if no fire code is available.
  • Method 2: Arrange business so that customers sitting at a table are not within six feet of any customers at another table (this distance would also apply to the tasting bar).
  • The Commonwealth will require commonwealth-created “COVID-19 Safety Procedures for Businesses” flyer to be clearly displayed at workplaces, along with publicly posted acknowledgement by the employer that the guidance is being followed. COVID-19-Reopening-Businesses-Flyer-8-5×11-1.pdf
  • There is also a requirement to name a “Pandemic Safety Officer” in charge of carrying out COVID-19 safety procedures.
  • Masks must be worn by workers and customers while entering, exiting or traveling throughout the business. Patrons may remove masks while seated or eating/drinking.
  • Those who cannot wear a mask due to a medical condition are not required to wear one and do not need to provide any documentation of such medical condition.
  • Protocols must be established to execute upon discovery that the business has been exposed to a person with probable or confirmed case of COVID-19.
  • Employees must be trained on importance and expectation of increased frequency of handwashing, the use of hand sanitizer with at least 60% alcohol, and avoidance of touching the face with hands. Make sure to document all training.
  • Provide masks for employees to wear at all times and make it mandatory to wear masks.
  • Where possible, stagger work stations to avoid employees standing right next to each other. If not possible, increase frequency of cleaning and sanitizing surfaces.
  • Verify that dishwashing machines are operating at the required wash, rinse and sanitize temperatures according to standard protocols.
  • Provide physical guides to ensure customers remain at least six feet apart. (ex: tape on floors or sidewalks and signage)
  • Assign employees to monitor and clean high-touch areas frequently. (ex: entrance doors, bathroom surfaces)
  • Clean and disinfect any shared items that customers come in contact with. (ex: tabletops, digital payment devices)
  • Live musicians performing at a restaurant, facility or venue must remain at least six feet from patrons and staff.

The following action items ARE ENCOURAGED according to the order of the governor’s office:

  • Establish a written, worksite-specific COVID-19 prevention plan, perform a comprehensive risk assessment of all work areas and designate a person to implement the plan.
  • In a risk assessment approach, the facility is divided into various functions and positions. The facility then assesses what could go wrong at each step of the process.
  • Controls are then put in place to prevent them from happening.
  • For additional information on COVID for Food Establishments and developing a prevention plan form please see the link for an article by Martin Bucknavage and Richard Kralj from the Penn State Extension Food Safety and Quality team entitled COVID Prevention Plan for Food Establishments.
  • Links to a COVID risk assessment form developed by the Occupational Safety and Health Administration (OSHA) are provided in the above document. Form examples are included (OSHA is the federal agency that investigates businesses where there is potential for infection).
  • Prior to each shift, ask that employees self-measure their temperature and assess symptoms. Below are a number of wellness questionnaires that may be utilized for this purpose.
  • Use single-use disposable menus (including tasting notes) and discard after each customer. Another option is to list wines available on a chalkboard and ask consumers to select samples from the list. Using reusable menus, other than digital menus sanitized after each use are prohibited in yellow phase.
  • Install physical barriers such as sneeze guards and partitions at point-of-sale terminals, cash registers, bars and other areas where maintaining six feet physical distance is difficult.
  • Provide hand sanitizer for customers and employees after handling credit cards or cash.
  • Schedule closure periods throughout the day to allow for cleaning and sanitizing.
  • Use separate doors to enter and exit the business when possible.

For the most up-to-date, reliable information, please continue to refer to the Commonwealth of Pennsylvania’s website for Responding to COVID-19 in Pennsylvania.    

Disclaimer: While Penn State Extension makes great efforts to produce the information within these protocols as timely and accurately as possible, we make no claims about the completeness of the contents and disclaim liability for errors or omissions in the contents. Remember that it is important to follow current federal, state and local regulations and guidance.

Note: We will host a panel discussion on the reopening of tasting rooms during COVID-19″ on July 22, 2020 as part of our webinar series. The announcement and registration link will follow soon.

References

Spotted Lanternfly Management in Vineyards 2020 – Webinar Recap

by Heather Leach, Extension Associate, Penn State Entomology 

Introduction 

Spotted lanternfly (SLF) populations are expected to be high in 2020 and some growers have already reported significant populations of nymph SLF in their vineyards. Remember that SLF feed on over 70 different plant species and will be present throughout the landscape, including areas surrounding your vineyard. All life stages of SLF except for the egg masses actively feed on plant sap (phloem). To date, grapevines have been the hardest hit agricultural commodity by SLF with ~30% of growers in southeastern PA reporting vine damage (dead vines, reduced yields) from this insect.  

Summary of 2019 Data 

In 2019, we learned more about the phenology and behavior of SLF in vineyards. Some of that work has recently been published, see here: https://link.springer.com/article/10.1007/s10340-020-01233-7  

The key takeaway points:  

-SLF are present in vineyards as nymphs, but typically not very numerous. The most problematic life stage is the adults, which are very numerous and most problematic in vineyards from late August-October.  

-SLF is an edge-pest with unequal spatial distribution within a given block. The “hot spots” with SLF typically stay that way for the majority of the season. Scout your vineyard regularly and learn these “hot spots”.  

– SLF flight activity is highest in the afternoon, and populations may increase on the vine throughout the day  

-After harvest, adult SLF begin feeding more heavily on the trunk (as compared to the shoots and cordon earlier in the season). When applying an insecticide, make sure you’re hitting the target.  

-Based on preliminary data, high levels of SLF feeding (200 per vine for ~5 weeks) reduce photosynthesis, transpiration, brix values, and cold hardiness (cv. ‘Riesling’). 

2020 Research Plans 

-Feeding trials to evaluate the damage that SLF causes to vines will continue  

-Additional insecticide trials, including testing new active ingredients, evaluating residual efficacy in-field, and application methods will be looked at 

-Landscape-scale control of SLF utilizing the biopesticide containing Beauveria bassiana is being evaluated in large trials in natural areas and in smaller trials adjacent to vineyards 

-Exclusion netting, flight-intercept traps, and utilizing tree-of-heaven will also be investigated for their use in vineyards 

Management 

-Specific questions about management of SLF on your vineyard can be directed to Heather Leach, hll50@psu.edu. Additionally, please review this factsheet for more information: https://extension.psu.edu/spotted-lanternfly-management-in-vineyards  

-The best control of SLF to-date in vineyards is the use of repeated broad-spectrum insecticides. Key pre-harvest products that are often relied on by growers for SLF management include the active ingredients zeta-cypermethrin, carbaryl*, malathion, dinotefuran, and thiamethoxam. For post-harvest, the longest lasting chemical is bifenthrin (which has a pre-harvest interval of 30 days). *Note that carbaryl has been reported as ineffective against SLF by some growers – this is being investigated for 2020.  

-There are no established action thresholds for SLF. The “best guess” approximation is ~15-20 nymphs/vine and 5-10 adults/vine. Please keep in mind that this is observation-based, not science-based. This threshold likely depends on other factors including pre-existing stress of the vine (e.g. presence of disease), age of the vine, and many other factors.  

-To avoid resistance (with SLF and other important vineyard pests like fruit flies), rotate chemical classes.  

-This year, we are seeing flare-ups of secondary pests (leafhopper, mealybug, mites) which may be attributed to the increased use of broad-spectrum insecticides for SLF control. Keep an eye on other pests in your vineyard.  

Please see this link for a PDF copy of the presentation on SLF detection and management in vineyards (from the June 17th webinar):