In its simplest form, a marinade is a seasoned liquid. Beyond that, all is fair. Often there is an acidic liquid and many times, an oil component. As for the flavoring, it can be any variety of herbs, spices, seeds, condiments, sugar -- and the list just keeps on going.
Enhance Flavor No matter what, a marinade will always impart flavor to the food.
"Tenderize" Food When there is an acidic component to a marinade, such as lemon juice, it may also serve to tenderize the food.
Marinades containing acid (such as wine, vinegar, or acids from food such as tomatoes) will denature the food that it flavors. Whether a marinade "tenderizes" food is a source of debate. What the acid truly does is break down the enzymes of the food on its surface. Many people feel that therefore the food is tenderized. Others translate the feeling of denatured enzymes on the food's surface as "mushy" rather than a "tender" mouth-feel (particularly if it is a less densely packed food such as fish that has been marinating a long time).
How much a marinade affects the texture of a food is a result of intertwined factors:
Protect Foods from Drying Out Oil protects leaner foods from drying out during high-heat cooking. It helps to hold in the natural moisture and reduce the loss of moisture during cooking.
These times serve as guidelines only.
Each pairing of marinade and food is different. The best advice is to know and trust the source of the recipe. If it has been properly tested, then the suggested times in the recipe will be accurate.
Times in a trusted recipe are guidelines. Most foods will not suffer irreparable harm by being marinated a little longer or shorter than suggested.
Marinating can be overdone, particularly if there is acid in the mixture and the food is less dense and small.
If the marinade has oil in it, be sure to pat the food dry before placing it on the grill. This will reduce the possibility of flare-ups from dripping oil.
Marinades can be wonderfully convenient. If you plan ahead, marinades can make a weeknight meal something really special -- and fast -- upon your return home from work.
A vinaigrette can be used as a no-fuss, easy marinade.