Is alcohol removed from wine or liquor when it is used for cooking?

Wine that is simmered for a long time in a stew would probably retain only a small fraction of its alcohol, but other dishes, like briefly flambeed crepes Grand Marnier or a soup with sherry added at the last minute, would probably still have enough to be of concern to those who want to avoid it altogether.

A study first reported in 1990 found evidence that alcoholic beverages retain from 5 percent to as much as 85 percent of alcohol after cooking.
In that study, six recipes using wine or spirits were prepared according to directions and analyzed.

The study found that the amount of alcohol left behind varied by the type of heat applied (simmering, baking, or flaming), the source of the alcohol (wine or spirits), the length of cooking, and the treatment of the food after preparation and storage.

A sauce made with Burgundy accompanying pot roast retained 5 percent of its alcohol after it had simmered for two and a half hours. Another wine sauce accompanying a chicken dish retained 40 percent of its alcohol. It simmered only ten minutes after the wine was added.

Forty-five percent of the alcohol in sherry used to make scalloped oysters remained after baking for twenty-five minutes. Brandy that was heated and quickly flamed before being served over cherries jubilee retained 75 percent of its alcohol.

Two tablespoons of a Grand Marnier sauce, cooked slightly, retained 85 percent of the alcohol. The liqueur was added to a hot liquid sauce after it had been removed from the heat.

A slice of brandy alexander pie, made with brandy and creme de cacao, was not heated. After it sat uncovered for sixteen hours in a refrigerator, the researchers found, it had lost 25 percent of its alcohol, probably through evaporation.

In other words, there can be enough alcohol left in food to be of particular concern to recovering alcoholics, pregnant women, and children old enough to eat the table food served to the rest of the family.

However, as food writers pointed out when the study was first reported in 1990, it seems likely that further heating of the cherries jubilee and cooking of the Grand Marnier sauce would have further reduced the alcohol content.