Marinades are a simple way to add big flavor to meat. There are thousands of flavor combinations possible with marinades, but every marinade should include a few basic components:
Fat is an important component in marinades because it helps transfer fat soluble flavors into the meat. A fat component will also help the meat retain moisture as it is cooked. Fats help ground flavor profiles and keep sharp or acidic flavors from overwhelming the experience. Examples of fat components in a marinade can include: olive oil, canola oil, coconut milk, full fat yogurt, or other vegetable oils.
Acids work in multiple ways to help flavor penetrate meat. Acids help break down the connective tissue in meat, which can slightly tenderize the meat and allow deeper penetration. An acidic flavor component is also important for balancing a flavor profile. A tangy top note provided by an acid ingredient will help add zing and freshness to an otherwise heavy flavor. Acids also act as antioxidants, which can counteract the free radicals that are produced when meat is cooked at high temperatures, as with grilling. Examples of acid components include: citrus juices, vinegar, wine, yogurt, or buttermilk.
Seasonings are where marinades really come to life. There are endless possibilities, but a good place to start is with aromatics. Aromatics like garlic, onion, or shallots provide a deep flavor base on which other flavors can be built. Herbs and spices, either dried or fresh, can be added to the marinade for extra layers of flavor.
Salt is also an important part of the seasoning process. Salt helps magnify the other flavors added to the marinade. Sea salt is an excellent choice as it contains minerals that provide extra flavor. Soy sauce is also a common ingredient used as the salt component in a marinade.
Chili peppers are a common ingredient in marinades because they add a uniquely spicy kick that can enhance many flavor profiles. Chile peppers, either dried or fresh, can be added to marinades.
Aromatics and chili peppers should be minced or cut into very small pieces when used in a marinade to increase the surface area and contact with the meat.
Citrus zest is a great way to add citrus flavor without adding extra acid to a marinade. The essential oils contained in the zest provide an exceptional amount of flavor, but contain no acid.
Sugars, such as honey, brown sugar, molasses, or agave nectar, are sometimes added to marinades to balance the acidic component. When used in lower heat cooking methods, such as roasting, the sugar will caramelize and add extra depth. When used with higher heat cooking methods, like grilling, the sugar may burn and cause an off flavor.
The ratio between fat and acid is subjective and often the source of much controversy. Generally, only a small amount of acid is needed and a ratio of 3:1 oil to acid is often used. Too much acid or too much time exposed to the acidic marinade can cause more tender cuts to become mushy.