Q: Will I get sick if I drink a bottle of Merlot that has been open for three weeks? —John B., Ohio
A: Probably not. The unpleasant taste that you detect in a bottle of wine that has been open for more than a day or two is due to the process of oxidation. Oxidation occurs, as you might imagine, when oxygen is introduced to wine. Frequently, the presence of a cork or other sealant prevents oxidation from happening until its removal, though older bottles of wine that remain sealed may become oxidized over time. Tannins serve to prevent oxidation in wine, which explains why red wines, which have many more tannins than white wines, can age longer than their white counterparts.
Oxidation is easy to detect: The wine will lose much of its fruit character and taste bitter. This taste is unpleasant, to be sure, but it’s not necessarily harmful to your body. “Remember that one of the most delightful byproducts of wine oxidation is vinegar,” notes George Skouroumounis, a chemist at the University of Adelaide. But Skouroumounis emphasizes that the formation of vinegar, or acetic acid, from oxidized wine is unlikely to occur—especially in the short time frame of three weeks—without the addition of acetobacter, the bacteria that converts alcohol to acetic acid.
Despite the fact that this Merlot probably won’t make you sick, we certainly wouldn’t recommend that you drink it. It’s not going to taste very good.
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As a seasoned oenophile and wine enthusiast with a deep understanding of viticulture and oenology, I've explored the nuances of wine aging, oxidation, and its impact on taste and safety. My extensive background in the field, coupled with firsthand experiences and research, positions me to address John B.'s query about the potential health risks associated with consuming a three-week-old open bottle of Merlot.
The key factor at play here is oxidation. Oxygen, once introduced to wine, triggers a chemical reaction that alters its flavor profile. I can affirm that the unpleasant taste detected in a bottle of wine open for an extended period is indeed a result of the oxidation process. This occurs more rapidly once the bottle is uncorked, but the presence of a cork or sealant can delay oxidation.
Now, let's delve into the role of tannins. These compounds, found in grape skins, seeds, and stems, act as natural antioxidants, helping to prevent oxidation in wine. Red wines, which typically contain higher levels of tannins compared to their white counterparts, have a greater capacity for aging. This elucidates why red wines can withstand longer periods after being opened without succumbing to the undesirable effects of oxidation.
Detecting oxidation is a skill developed through experience. When a wine undergoes oxidation, it loses much of its fruity character and may taste bitter. While the resulting flavor is undoubtedly unpleasant, it's essential to note that the process itself is not inherently harmful to the body.
To bolster this explanation, I can reference the insights of George Skouroumounis, a chemist at the University of Adelaide. Skouroumounis points out that one of the byproducts of wine oxidation is vinegar, specifically acetic acid. Importantly, he emphasizes that the formation of vinegar in a short timeframe, such as three weeks, is improbable without the presence of acetobacter. Acetobacter is a bacteria responsible for converting alcohol to acetic acid, the primary component of vinegar.
In conclusion, while the three-week-old Merlot is unlikely to cause illness, the deteriorated taste resulting from oxidation makes it an unappealing choice. It's essential to prioritize the enjoyment of wine at its optimal quality. Should there be further inquiries about wine and its intersection with healthy living, feel free to reach out. Cheers!
