Wine does lose alcohol over time, but under normal conditions the loss is so small you’d never notice it. An opened bottle sitting on your counter for a few days won’t meaningfully change in alcohol content. It would take weeks or longer to measure any real difference, and by that point the wine would likely taste like vinegar anyway. The situation changes dramatically, though, when heat, cooking, or long-term barrel aging enters the picture.
What Happens After You Open a Bottle
Once you pull the cork, both the water and alcohol in wine begin to evaporate. Alcohol evaporates somewhat faster than water because it has a higher vapor pressure, meaning its molecules escape into the air more readily at room temperature. But wine is mostly water with only about 12 to 16 percent alcohol by volume, so there just isn’t that much alcohol available to evaporate in the first place.
The practical result: any alcohol loss from an open bottle is negligible. You’d need to leave wine exposed to air for days or weeks before a lab could detect a meaningful drop. And long before the alcohol evaporated away, bacteria called acetobacter would start converting that alcohol into acetic acid, turning your wine into vinegar. So an open bottle goes bad in flavor well before it loses its alcohol content in any significant way.
Why Cooking Doesn’t Burn Off All the Alcohol
A common belief is that alcohol “cooks off” entirely when you add wine to a hot pan. Alcohol’s boiling point is 173°F (78°C), well below water’s 212°F (100°C), so it seems logical that heat would drive it all away. In reality, alcohol and water form a mixture that doesn’t behave like two separate liquids. A good portion of the alcohol hangs on stubbornly.
USDA data on alcohol retention tells the story clearly:
- Flambéed dishes: Around 75% of the original alcohol remains, despite the dramatic flames.
- 15 minutes of simmering: About 40% remains.
- 30 minutes of simmering: About 35% remains.
- 1 hour of simmering: About 25% remains.
- 2 hours of simmering: About 10% remains.
- 2.5 hours of simmering: Around 5% remains, the lowest typical cooking achieves.
Even after hours of simmering, a trace of alcohol persists. For most people this is trivial, but if you’re avoiding alcohol entirely for medical, religious, or personal reasons, it’s worth knowing that cooking with wine doesn’t produce a truly alcohol-free dish.
How Barrel Aging Changes Alcohol Levels
Wine aging in oak barrels is a different story from a sealed bottle. Barrels are slightly porous, allowing slow evaporation over months or years. Winemakers call the liquid lost this way the “angel’s share.” Whether that evaporation lowers or raises the alcohol percentage depends heavily on one factor: humidity.
In a cool, humid cellar (around 70% humidity), alcohol evaporates faster than water through the barrel walls. This gradually lowers the wine’s alcohol content. Some winemakers deliberately age wine in barrel for extended periods partly for this reason, with some reporting a drop of about half a percentage point in alcohol. In high-humidity cellars in France, for example, wines come out of barrel lighter in body and lower in alcohol.
In a dry cellar, the opposite happens. Water evaporates faster than alcohol, concentrating the remaining liquid and actually pushing the alcohol percentage up. In some dry California cellars without humidity control, wines have gone into barrel at 15% and come out at 16.5%. A winemaker on the Central Coast reportedly used extended barrel time in dry conditions specifically to raise already-high alcohol levels.
Alcohol Loss During Bottle Aging
Once wine is sealed in a bottle, evaporation slows to a crawl. A properly corked or screwcapped bottle allows almost no exchange with outside air, so the alcohol content stays essentially stable for years. Research conducted at Mouton Rothschild, one of Bordeaux’s most famous estates, found that alcohol levels decline by roughly half a percentage point over 20 years of bottle aging. That’s a change so gradual it has no practical impact on any bottle you’re likely to drink.
The tiny amount of change that does occur in bottle comes from slow chemical reactions rather than evaporation. Alcohol molecules can combine with acids in the wine to form new compounds called esters, which contribute to the complex aromas of aged wine. This process consumes a small amount of alcohol, but not enough to affect the ABV you’d read on the label.
What About Freezing Wine?
Freezing wine doesn’t reduce its alcohol. It actually concentrates it. When wine begins to freeze, the water crystallizes into ice first because water freezes at a higher temperature than alcohol does. The unfrozen liquid left behind contains a higher concentration of alcohol, sugar, and other dissolved compounds. This is the same principle behind “freeze concentration,” a technique historically used to make stronger beverages like applejack by freezing hard cider and removing the ice.
A typical wine at 12% alcohol starts to freeze around 22°F (-5°C). As ice forms and you remove it, the remaining liquid climbs in alcohol percentage. You’d need to reach extremely cold temperatures, around -75°F (-59°C) or lower, to freeze a solution that’s 80% alcohol. So if your bottle froze in the car overnight and some liquid remained unfrozen, that liquid portion is stronger than what you started with.
Factors That Speed Up Alcohol Loss
Three variables control how quickly alcohol leaves wine in any scenario: temperature, surface area, and airflow. Higher temperatures give alcohol molecules more energy to escape into the air. A wider, shallower container exposes more liquid to the atmosphere. And moving air carries evaporated alcohol away from the surface, preventing it from settling back into the liquid.
This is why a pot of wine simmering on the stove loses alcohol far faster than a glass sitting on a table. The stove provides high heat, the pot offers a broad surface, and the rising steam creates airflow. A wine glass at room temperature in a still room has none of those advantages, which is why casual evaporation is so slow as to be irrelevant. If you recork or reseal an opened bottle and refrigerate it, you’ve minimized all three factors and the alcohol content will remain virtually unchanged for days.