Q: Can a homemade wine, or any part of the winemaking process, be responsible for unpleasant physical symptoms such as stomach pain or nausea?—Frank, Pittsburgh
A: When it comes to homemade wine and health, the golden rule is to follow the rules. "If a wine was made following standard winemaking procedures, and if the additives are FDA approved," Cal Poly enology professor and winemaker Dr. Federico Casassa told Wine Spectator, "then it is very unlikely a wine will cause any specific physical symptoms just because it is homemade."
There are still a few hazards that should be addressed, however, including the amount of yeast used. "Homemade wines tend to have a little more yeast than wines purchased at a store," said Dr. Jamie Alan of Michigan State University’s Department of Pharmacology and Toxicology. "The issue with too much yeast in the wine is that it can be fermented in the gut and cause unpleasant bloating." Also, Dr. Alan emphasizes using pre-sterilized, food-grade containers and high-quality filtered water to prevent bacterial contamination. She also notes that there have been cases of lead poisoning resulting from using a bathtub as a fermentor (bathtubs are not considered food-grade containers). Lead poisoning can cause gastrointestinal and neurological symptoms, along with dizziness from the anemia it may cause as well. Although wine's high ethanol content and overall absence of nutrients partly halts the development of microbes, there are still measures in the winemaking process that can cause unpleasant symptoms if not taken seriously.