Role of alcohol in cooking.

A glass of wine with dinner makes a meal more civilized and enjoyable. Yet the real power of alcohol, especially for the cook, lies not in what it does at the table but what it does in the kitchen.

Like salt, alcohol brings out the flavor in food. Whether you’re cooking with wine, beer, or liquor, the alcohol in those beverages improves flavor perception in at least two important ways: by evaporation and by molecular bonding. Let’s take them one at a time.

Into thin air
Open a bottle of 16-year-old Lagavulin single malt and you smell the scotch right away. The alcohol molecules swiftly carry subtle caramel aromas and soft peaty smoke to your olfactory sensors (that is, your nose). The alcohol molecules can do this because they’re volatile, meaning they evaporate rapidly.

That’s why adding a splash of kirsch to a fruit salad or macerating peaches in Pinot Noir helps convey the fruit’s aroma to our nostrils, enhancing our overall enjoyment of the food. This “volatility effect” works best when a dish contains a low concentration of alcohol-1 percent or less. If more than 5 percent of the dish is alcohol, the aroma of the alcohol will dominate.

Hitching a ride
Food also benefits from alcohol’s second remarkable quality: It bonds with both fat and water molecules. In this way, alcohol bridges the gap between our aroma receptors (which respond only to molecules that can be dissolved in fat) and food (which consists primarily of water). This is crucial, because most of the great “flavor” in food comes from aromas in the nose rather than tastes in the mouth. (Notice that you can’t fully “taste” your food when you have a stuffy nose.)

Alcohol’s ability to bond with both fat and water is well illustrated by a marinade or brine. In this case, the flavor compounds in aromatics like garlic, herbs, or other seasonings dissolve only in fat (i.e., they are fat-soluble). Alcohol helps carry those compounds into the meat that’s soaking in the marinade. At the same time, alcohol also carries any water-soluble flavor compounds into the meat’s cells. (Water-soluble flavors include sweet, sour, salty, and bitter.) The result of alcohol’s efforts? More flavor and aroma in the marinated food. And it doesn’t take much: Adding even a tablespoon of neutral-tasting vodka to a marinade or brine noticeably improves the flavor penetration of the marinade.

The same principle is at work when you baste a piece of meat with wine, beer, or spirits during cooking. Of course, the liquid helps moisten the meat’s surface, but the alcohol also carries flavor compounds into the meat, improving its taste.

High intensity
Alcohol’s enhancement of flavor perception can be seen in reduction sauces as well. When you deglaze a pan with wine after searing a steak, not only are you capturing the deliciously browned proteins stuck to the bottom of the pan, but you’re also dissolving them in alcohol, which carries additional flavor to the sauce. If you deglaze with a nonalcoholic liquid such as broth, fruit juice, or water, the flavor of your sauce won’t be as intense.

With both of alcohol’s flavor-enhancing abilities, less is more. When it comes to evaporation, just a jigger of tawny port in a braised beef dish can make a distinct difference in flavor perception. And with molecular bonding, just a splash of a spirit in a marinade intensifies the flavors in the finished dish. All the more reason to bring alcohol into the kitchen.