Whether a bottle of wine that has gone “bad” can cause genuine sickness, such as food poisoning or a dangerous infection, is a common question. The answer is generally no, but the distinction between spoiled-tasting wine and a truly contaminated beverage is important. “Getting sick” from wine usually refers to gastrointestinal distress or adverse physiological reactions, not infection from a pathogen. Commercially produced wine is safe from a microbiological standpoint, though certain wine faults and natural compounds can still lead to unpleasant, non-infectious reactions.
Is Spoiled Wine Pathogenic?
Wine is a hostile environment for the bacteria that cause human food poisoning. The combination of high acidity (low pH, typically 2.9 to 3.9) and alcohol content makes it nearly impossible for pathogens like Salmonella or E. coli to survive. The ethanol content (usually 10% to 15%) further inhibits bacterial growth, acting as a natural antimicrobial agent.
The microbes responsible for wine spoilage are not pathogenic to humans. For example, Acetobacter species convert ethanol into acetic acid, turning the wine into vinegar, which is harmless to consume. Spoilage yeasts like Brettanomyces only affect the flavor, producing undesirable aromas, but pose no physical health risk. The antimicrobial factors present in wine, including organic acids and polyphenolic compounds, result in a low microbiological food safety risk.
Common Causes of Wine Spoilage
The most common wine defects that make a bottle taste bad are matters of quality and flavor, not safety. Oxidation occurs when wine is exposed to too much air, causing it to lose fresh fruit character and develop flat, nutty, or bruised apple notes. This process is safe, and the resulting oxidation products are not toxic. Consuming oxidized wine will not cause infection or food poisoning.
Another common fault is volatile acidity, which is the presence of acetic acid and its derivatives, giving the wine a sharp, vinegar-like smell. While unpleasant, vinegar is not harmful to ingest. A wine with cork taint, caused by the compound 2,4,6-trichloroanisole (TCA), will smell like a musty basement or wet cardboard. TCA itself has no harmful effect on humans, meaning a corked bottle is safe to consume, though the flavor is often ruined.
Rare Scenarios for Contamination
While commercial wine is overwhelmingly safe, extremely rare contamination risks exist, mostly related to mycotoxins. Ochratoxin A (OTA) is a mycotoxin produced by molds, mainly Aspergillus carbonarius, which can infect grapes in the vineyard. If grapes are heavily rotted before winemaking, this toxin can be transferred into the wine.
Modern winemaking practices, including clarifying the wine and using fining agents, reduce OTA levels, and international regulations set maximum tolerable limits for this compound. A more common, though still rare, risk involves opened bottles that are improperly stored. If an opened bottle is left for a long period, especially low-alcohol or sweet wines, massive mold or bacterial growth can occur, which could theoretically cause stomach upset.
Non-Pathogenic Reasons for Feeling Sick
Many adverse reactions attributed to “bad wine” are physiological responses to natural wine compounds. Biogenic amines, such as histamine and tyramine, are produced during fermentation, particularly in red wines that undergo malolactic conversion. In sensitive individuals, these amines can trigger symptoms like flushing, headaches, nausea, and gastrointestinal discomfort, sometimes mistaken for food poisoning.
Sulfite Sensitivity
Sulfite sensitivity is a common culprit for adverse reactions, especially in asthmatics, where the preservative can cause respiratory symptoms like wheezing, or digestive issues like stomach cramps and diarrhea. True sulfite allergies are rare, but sensitivities affecting the respiratory or digestive system are more common.
Tannins and Digestive Upset
The tannins found primarily in red wine can irritate the stomach lining in some people. Tannins have astringent properties and can cause nausea, cramps, or general digestive upset, especially when consumed on an empty stomach.