Production Tips for the Home Winemaker
By: Denise M. Gardner
Home winemaking and home brewing can be some fun hobbies for enthusiasts or amateur growers and winemakers. However, most home winemakers experience the same set of problems year after year without practical solutions for how to fix their wines or avoid challenges during production. The following blog post discusses some possible considerations when making wine at home.
Concentrate – Grapes – or Juice
One thing to note is that concentrates are produced and manufactured with a pretty high success rate that the fermentation will complete with some sort of noticeable quality resembling wine. These end up being the best product to use as an introductory fermentation base for those just starting to learn about the winemaking process. The concentrate is simple: pour into the fermentation vessel and “just add water and yeast.”
The problem with concentrates is that they are easily identifiable, meaning the finished wines have a specific taste and quality standard that is noticeable sensorially regardless of the variety or source of the concentrate. These wines will likely appear “simple” with nuanced fruit characteristics and a strong perception of alcohol.
However, when home winemakers switch to purchasing bulk juice or grapes, many new fermentation problems can arise that they did not experience during their use with concentrates.
This is due to the fact that bulk juices (purchased from a broker or home winemaking supply store) may contain preservatives (i.e., sulfur dioxide) that can make the initiation of fermentation more challenging. Additionally, juice and grape quality is dependent on the source and how long the material was in storage before it arrives to the home winemaker’s fermentation vessel.
With juice and grapes, you are also dealing with the native microflora (e.g., yeast and bacteria), some of which can also be spoilage microorganisms, which can have numerous effects on fermentation kinetics and the finished wine quality.
However, using grapes or bulk juice as the starting base will provide a finished product that is more representative of where the grapes were grown (i.e., terroir representation) and provide the winemaker with more options for making the product unique.
Basic sanitation is what many home winemakers struggle with the most during fermentation and wine storage.
While most commercial sanitizers are not available to home winemakers, basic cleaning and sanitizing principles can easily be applied to home winemaking practices.
First, always make sure equipment is pulled apart and fully cleaned with hot water, a small (very small!) amount of non-scented dish soap, and some good, old fashioned elbow grease. Removing debris and build up from all of the processing equipment improves the efficacy of a sanitizer. Cleaning is at least 95% of sanitation, and this theory is true in home winemaking as well.
After the equipment is properly cleaned and rinsed with hot water, sanitation can follow. Using a citric acid – sulfur dioxide blend in cold water is a good no-rinse sanitizer that home winemakers can utilize. However, it is important that home winemakers take the care and precaution to ensure safety associated with using volatile sulfur dioxide. Volatile sulfur dioxide is a lung irritant and can cause serious health issues if used improperly. People with asthma or other lung-related conditions should not come in contact with potassium metabisulfite or sulfur dioxide. For more information pertaining to how to properly use sulfur dioxide, please refer to Penn State’s Wine Made Easy Fact Sheet and your potassium metabisulfite supplier.
The citric acid – sulfur dioxide sanitizer is a no-rinse sanitizer. This means that after the equipment has been sanitized, the juice or wine can come in contact with the equipment without any worry by the home winemaker. Both citric acid and sulfur dioxide are naturally found in wine, so its use should not alter the flavor of the wine in any way.
Use Nutrients during Fermentation
Many home winemakers use non-specific yeast nutrients during fermentation. However, the research and commercial industry worlds, we have started to learn that nutrient additions need to be specific towards the fermentation. Look to see if you can find commercial suppliers of yeast nutrient from companies like Beverage Supply Group, Christian Hansen, Enartis, Laffort, or Lallemand (to name a few of the suppliers). Some home winemaking supply stores will carry small quantities of these products, and they are worth the purchase.
At minimum, using a yeast hydration nutrient (like GoFerm or an equivalent) will help to start the fermentation positively. Complex nutrients (like Fermaid K or an equivalent) are typically recommended (up to a certain point) before using DAP.
If you can find a way to measure yeast assimilable nitrogen, or YAN, then nutrient additions can be made in specific quantities, using specific products (i.e., hydration nutrients, complex nutrients, or DAP) at the start and 1/3-of-the-way-through fermentation. Utilizing the supplier’s guidelines for the rates of additions of your products, based on the starting YAN concentration, is a good way to minimize the risk of the wine tasting like rotten eggs or canned vegetables.
Manage Oxygen Exposure
Winemaking is tedious. It requires the winemaker to constantly check and monitor the wine to ensure that things have not gone awry.
Home winemakers should try their best to minimize long-term oxygen exposure. Using vessels to minimize surface area at the wine-oxygen interface will help reduce the risk of acetic acid bacteria contamination and growth, which contribute to the volatile acidity (i.e., the acetic acid – or vinegar – and nail polish flavors) of a wine.
If you need to “top up” carboys, use sanitized marbles to “push” the volume of the wine up into the neck of the carboy. This helps minimize the surface area at the oxygen interface.
Avoid letting the wine “sit” without an active primary fermentation or malolactic fermentation (MLF). Make sure when both of these fermentations are complete, properly treat the wine with potassium metabisulfite to ensure preservation and stability.
Keeping the wines stored in a cool location will help minimize bacterial growth or yeast spoilage, while preserving the wine.
Bottling the wines as soon as you can post-production can help ensure quality and stability.
Avoid Making Wines in Aromatic Environments
One problem that some home winemakers face is aromatic absorption associated with the odor of the environment in which the wine was produced. This tends to be a problem when wines are made in an unfinished basement.
Wines are alcoholic solutions, which can absorb surrounding odors. As unfinished basements tend to have that “wet basement” odor, the wine will likely absorb that aroma and flavor into the finished product. However, many people may not be aware of the flavor until after the wine is removed from the odorous environment.
These are just a few solutions pertaining to home winemaking situations. However, you can find more resources, including “how to” book recommendations on the Penn State Extension Enology website.
Need more help in learning how to identify wine problems? Check out some of Penn State’s local workshops pertaining to wine defect identification. The next workshop is coming up on June 9th, 2016!