Bitter, Brawny and Brilliant

• Vinegar is the natural result of bacteria converting ethanol alcohol to acetic acid. The alcohol is typically beer, wine or cider, but fermented rice, malt and various fruit juices are also common. Each type of vinegar adopts flavor traits from its parent alcohol, along with vitamins and minerals that contribute a distinct taste. Levels of acidity range from 4 to 7 percent, and vinegar's average pH is between 2 and 3.5. Vinegar's low pH is specifically what stresses protein molecules, unraveling their tightly wound matrices and chemically cooking them, or denaturing them, such as in a dish like salmon ceviche.

Skip Heat, Use Vinegar

• Vinegar cooks salmon gradually. Similar to cooking with heat, the amount of time you marinate salmon in a vinegar-based marinade determines how done the salmon will be. Ten to 30 minutes is the optimal time frame, with the lower end corresponding to medium, and the upper end to well done or cooked through. Vinegar is too acidic to serve favorably as a solo marinade ingredient. For the same reason, a scant splash or two mixed into sour orange juice or white wine is sufficient to cook salmon thoroughly while infusing it with sparkling, nuanced flavor. Enliven the marinade with a dash of cilantro and red onion.

A Transcendent Seafood Dish

• Cooking fish in acid calls to mind ceviche, and vinegar is often the acid of choice. The dish's origins are unknown, but one theory suggests the arrival of Spaniards in Mesoamerica introduced citrus to an old Inca method of preserving fish in maize juice. Ceviche is both an appetizer or main dish depending on what accompanies it. Any kind of seafood is a viable choice, such as shrimp, squid, tilapia, striped bass, grouper or salmon. Select the freshest fish possible. It should be firm to touch, have shiny flesh, clear and protruding eyes and it shouldn't smell fishy. If using frozen fish, defrost under running cold water or in the refrigerator until just thaw. For best results when making ceviche, dice the fish into bite size pieces before marinating to increase surface area.

Sour But Still Safe

• Though vinegar chemically "cooks" salmon, vinegar's acidity doesn't kill all microbes associated with foodborne illnesses. The United States Department of Agriculture recommends heating the salmon to 145 degrees Fahrenheit to achieve this aim. An alternative is poaching the salmon for 5 to 10 minutes before briefly marinating it. To prevent the spread of microbes, wash and sanitize all work surfaces and implements after handling raw fish and meat. Serve vinegar-cooked salmon promptly to prevent the growth of bacteria within the dish.