The Science of Marinades

Published: November 14, 2015

Marinating food prior to cooking is the essence of food preparation for all types of grills, roasts and so on. Whether it’s a short dip or a long soak, marinating enhances a variety of foods. It’s a versatile and indispensable technique which helps to boost the flavor of meats and vegetables.

Marinating refers to soaking food in a flavorful liquid called a marinade. Marinating is a technique that’s been around at least since the Renaissance, when acidic mixtures were commonly used to help preserve foods.

One always speaks of marinating when they would like to tenderize food. But, contrary to this popular belief, marinating only flavors, not tenderizes, food.  You may also think marinating is time-consuming, but this is true only if you think marinating is to tenderize. In fact marinades only permeate the surface of the food and have little effect on the interior. If you really have no time, simply smear the food with the sauce or marinade as it is going on the grill or the pan. Tenderizing really comes from the way you cook it.

The beef steaks, shown in this picture, were left in the marinade for a couple of hours but the pink centre cleary illustrates how far the marinade has penetrated, which is only the outer layers of the steaks. Of course this would depend on the thickness of the meat, for thin cuts the marinade would permeate evenly.

Beef Steak step1

Beef Steaks in Marinade

The first and most basic of marinades almost always include an acidic element, such as citrus juice or vinegar which boosts flavors and may tenderize the surface proteins of meat.  Oil is another common constituent as it helps coat food, carries flavor and helps food stay moist.  Ingredients such as garlic, ginger, soy sauce, pepper, chillie, enhance the savory qualities of meats and fish.

The second type of marinade included the use of wine/alchohol.  However, when marinating fish or meat that is to be grilled or sauteed, avoid using wine or alchohol, because these cooking methods only heat the meat to about 135 to 165 degrees, well below the boiling point of alcohol, leaving  the meat with a taste and flavor of alcohol. Wine is fine for using in stews and braises because these dishes are cooked for a prolonged period at a temperature that boils off the alcohol and eliminates any harsh flavors.

A third kind of marinade includes those that ‘cook’ raw foods, usually seafood, as in the popular Latin dish Seviche.  Lime and/or lemon juice turns the flesh opaque and firm so it appears “cooked” but the food is actually still raw. Although the acid in a marinade appears to “cook” raw fish in a seviche, it doesn’t eliminate bacteria the same way cooking with heat does. When marinating fish that won’t be cooked, make sure the fish is sushi-grade, or frozen-at-sea (FAS) fish; both are safe for healthy adults to consume raw.

A fourth category of marinade is used to marinate cooked fish in a vinegar-based mixture to impart more subtle flavors. This type of dish is called Escabeche.

Foods kept for marinating should never be kept in aluminium or copper containers as the marinade is acidic and as these metals are reactive, the acids and will promote discoloration of the food and give it a metallic taste.  It is best to use non-reactive containers like glass, ceramic or stainless steel, even plastic is better than aluminium or copper.

Always marinate meat and fish in the refrigerator.  Some of the marinade may be used for basting after removing the meat or fish from it only if the marinade is boiled and cooked for five minutes to kill any bacteria. Marinade brushes and other utensils that are used with raw food should not be used again near the end of cooking.

The length of time you marinate food depends on both the food and the marinade. Delicate fish, shellfish and fruit usually soak for a shorter period of time (from 20 minutes to a few hours), while meats can go longer (up to a day or two, but I would really not want to go beyond 24 hours to preserve the texture of the cooked food). It is really not necessary to soak food too long in a marinade but I find it easier to marinate overnight or say half a day in advance, mainly for reasons of convenience. This allows pre-preparation of food and also for cooking to be done in stages to reduce the pressure and time rather than cooking from start to finish in one go. Especially for occasions, I usually plan a menu around food that requires some sort of marinating so that half the preparation can be done the previous night for an afternoon party or in the morning of the day for a dinner event. However meats should not be soaked in a highly acidic marinade too long as it would alter the texture of the meat which may turn grainy and mushy. If a recipe calls for half-cup of lemon juice, then that is a red-flag.

The science seems clear. ”Acid does break down protein, but after it breaks it down, it causes it to coagulate,” said Shirley O. Corriher, whose book, ”Cookwise” (William Morrow & Company, 1997), explores the reasons some recipes work and others do not. ”If you leave it too long, it toughens or turns to mush.”

While some may be tempted to poke holes in the meat to extend the flavoring beyond the surface, that technique has more drawbacks than benefits. It may improve the distribution of flavor, but more fluid will be lost during cooking, resulting in drier meat.

For Grilled Chicken Example I – The chicken was poked all over with a fork thinking the marinade would penetrate the meat and it would turn out more tasty, but instead the meat turned out dry and the skin shriveled up under the grill and the final presentation did not have a very appealing look.

Grilled Chicken 1

Grilled Chicken Example I

Grilled Chicken Example I

Grilled Chicken Example II – Marinade spices were smeared without poking holes in the chicken and the result was tender and juicy grilled chicken and which looked deliciously appealing.

Grilled Chicken Example II

Grilled Chicken Example II

Another acidic ingredient that has many fans is yogurt. In Indian cooking when food is prepared for the tandoor yogurt breaks down the fiber and tenderizes the meat. Science seems to support the yogurt partisans. Yogurt not only has a far milder acid than those in wine, lemon juice and vinegar, but also contains calcium, which activates enzymes in meat that break down the muscle fiber.

One area where even a harmonizing marinade is not necessary is with an ingredient that is already great and distinctive, like an excellent cut of meat, which needs no marinade to add flavor. (Credits: James Peterson, Mark Bittman, Eric Asimovor)

Illustrations & Recipes :

Tandoori Chicken

Tandoori Chicken

Recipe for Tandoori Chicken using yogurt marinade

Grilled Chicken (1)

Grilled Chicken

Recipe for Grilled Chicken using lemon juice

Beef Roast

My mum’s (Mais Recipes) Roast Beef recipe using vinegar

Chilli Beef8

Chilli Beef

Recipe for Chilli Beef using soy sauce,

All delicious and flavorful in their own right and enhanced with the appropriate combination of marinade ingredients.


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