Vinegar is a sour-tasting liquid used in cooking and cleaning, made when bacteria turn alcohol into acetic acid. If you've ever smelled the sharp, tangy scent of a pickle jar or tasted the zing in salad dressing, you know vinegar.

People have made vinegar for thousands of years, often by accident: when wine or cider sits exposed to air, natural bacteria convert it into vinegar. Today, vinegar comes in many varieties. White vinegar works for cleaning windows or removing stains. Apple cider vinegar adds flavor to recipes. Balsamic vinegar, aged in wooden barrels, becomes sweet and complex enough to drizzle over strawberries.

Vinegar preserves food, which is why pickles last so long in jars. It also makes baking soda fizz dramatically in volcano experiments. In cooking, a splash of vinegar can brighten flavors that taste flat or dull.

The word appears in the expression you catch more flies with honey than with vinegar, meaning kindness works better than harsh words when you want someone's cooperation.