As Alex Guarnaschelli told Food & Wine, the worst mistake one can make when cooking with wine is not letting the alcohol cook out of it before adding other liquids to the dish.

For instance, if you're adding wine to a sauce or braise, you should add it to your aromatics in the pan and let the alcohol fully cook before adding in a stock or tomato sauce.

Per Guarnaschelli, if you don't fully allow your wine to cook, "there will be that uncooked wine flavor." This can make your dish slightly bitter, throwing off its flavor profile.