No one likes dry, flavorless meat, and for thousands of years cooks have devised methods for keeping cooked meat juicy as well as enhancing its flavor. Many of these techniques fall into one of three categories: brines, marinades, and rubs.
Brining is a technique mainly for keeping meat from drying out when cooking, and secondarily for making it a bit more flavorful. It involves soaking meat in a saltwater bath for anywhere from 15 minutes to several hours.
There’s a lot of bad information out there about what brines actually do, many suggesting that it has something to do with osmosis (it doesn’t – see the note at the end of this article for an explanation). Rather, a brine diffuses the dissolved salt into the meat, and then takes advantage of the effect salt has on proteins.
Proteins in their naturally occurring form are long strings of amino acids that are folded up into intricate forms, in part to strengthen them, but also because the folds (and the places where amino acids touch each other) are important to their function. Mildly salty water causes proteins in the meat to denature, which means that the folds unravel and the protein becomes one long strand. Denatured proteins can trap water molecules, much like how a head of long hair can stay wet for a long time. So a weak saltwater brine can cause meat to absorb and retain more waiter, keeping it juicier as it cooks.
But here’s the trick. A very salty solution has the opposite effect on proteins: it actually tightens them up and squeezes out any water molecules, leaving meat dry and tough. Before refrigeration became commonplace, meat was preserved by covering it with a layer of salt, which would dry out and toughen the outer layer; dry meat deprives bacteria of the water it needs to thrive and multiply, thus keeping the meat from going bad.
What this means is that we want to brine our meat with just enough salt to denature proteins, but not enough to dry and toughen it. There are complicated formulas for calculating this, but as a general rule most brines for meat use 1 cup of kosher salt for every gallon of water.
Brines can often contain other ingredients that either enhance flavor or affect the texture of the meat in other ways. Sugar, for example, will provide some sweetness to counteract the saltiness, but equally important it will caramelize as the meat cooks, enhancing browning (which adds flavor).
The length of time you need to brine meat depends on the thickness and toughness of the meat. A boneless chicken breast may take only 30-60 minutes; a 20-pound Thanksgiving turkey takes hours. Delicate fish, including most white fish, may only need to brine for 15 minutes. But don’t brine meat at room temperature for more than an hour, because bacteria will grow freely and create a food-safety issue. Meat can be safely brined in the refrigerator for hours, though.
When done brining, there are two important steps that must be taken. First, thoroughly pat dry the meat, as liquid remaining on the outside will interfere with the cooking process. Second, throw away the brine: it’s been contaminated with bacteria from raw meat and is not safe.
Marinating meat (and other ingredients, such as vegetables) is primarily a means to add flavor. For some marinades a second goal is to “tenderize” meat, especially tougher cuts; however, the use of a marinade to tenderize is wildly oversold. The only reliable method to tenderize meat is to cook it.
The flavor-imparting ingredients in a marinade are generally large molecules that can’t penetrate into the meat’s cells, so they don’t get very deep into the meat even if it’s marinated for a long period of time. But to assist with this process, most marinades contain either an acid or an enzyme that starts to break down the proteins so that the flavor agents can penetrate a little deeper. A mildly acidic marinade will denature the proteins a bit (like a brine does), giving a more “tenderized” texture; a stronger acid will break the proteins down entirely and can turn the meat into an unappetizing mush. Similar to how brines can only be mildly salty, marinades can only be mildly acidic or they do more harm than good. And let’s not forget that since marinades don’t penetrate very far into meat, any tenderizing they do will only affect the outer part of the meat. One might imagine that marinating meat for longer will give the marinade time to work its way deeper into the meat; and to a certain extent that might be true especially for tougher cuts of meat, but the longer marinating time means that the acid will do much more damage to the texture of the outer part of the meat. In short: marinating is a very good technique for adding flavors to the outer layers of meat and vegetables; it’s a poor technique for tenderizing meat.
Common acids used in marinades include wine, vinegar, and citrus juices. They all have different levels of acidity, and so they are not one-for-one interchangeable. Also, wine has both acid and alcohol: the acid can be good, but the alcohol can have a very negative effect on meat texture. If you plan to use wine in a marinade, you will often need to boil off its alcohol first.
There are a handful of enzymes that are also effective in breaking down meat proteins; the most common naturally-occurring ones used in marinades are in pineapple, papaya, and ginger. Store-bought marinades will often contain manufactured enzymes. Some of these enzymes, including the natural ones, are very effective: try marinating meat in pineapple juice for a few hours, and you will be stunned (and not in a good way) at the effect it has on the meat. If you are using an enzyme-based marinade, pay close attention so that you don’t let it marinate for too long. As mentioned above, tougher cuts of meat can withstand longer marinating times.
Another common marinade ingredient is dairy, often either yogurt or buttermilk. Most dairy products are slightly acidic, but it’s believed that some of their other ingredients help to protect the texture of the meat.
Because marinades don’t penetrate deeply, and because you don’t want to marinate your meat for too long, it often helps to score or slash the meat to allow the marinade to seep deeper in, or just simply to cut the meat into smaller pieces so there is less thickness that the marinade needs to penetrate. You can also buy a “flavor injector,” which is essentially a big syringe for injecting marinade deeper into a thick cut of meat, if you really care about adding that flavor all the way through the meat.
Many marinades also contain salt, which is fine (as long as it isn’t too much salt) – it’s okay to have one liquid that serves as both a marinade and a brine. Just be aware that even if you combine them, they will act independently: the salt will penetrate into the meat, but it won’t bring any of the other ingredients with it.
As with brines, marinades that come into contact with raw meat are no longer safe for direct consumption; they should either be thrown away immediately, or boiled for 15 minutes to kill any bacteria. If you want to use some of the marinade as a sauce while cooking or for pouring over the meat when served, set aside some of the marinade for that purpose before you combine the raw meat and marinade, so that it never comes into contact with anything that might contaminate it with bacteria or other pathogens.
Also like brines, make sure to thoroughly pat the meat dry after marinating but before cooking.
Rubs are a method of creating a layer of flavor agents on the outside of meat, a kind of “crust of flavor.” They are usually dry: just herbs and spices with a bit of salt, but no liquid. Rubs generally don’t penetrate into meat, though they can potentially help keep meat a bit juicier in the same way that breading can, by providing a layer of protection for the meat from the effects of high heat. But at the same time, a dry rub itself can burn under high heat. If you’re making Cajun food, then “blackening” may be what you’re going for; otherwise, be careful. Cooking over medium to low heat may be better with a dry rub; or alternatively rub some oil on the outside of the meat before applying the rub if you plan to use high heat, since the oil can help protect the rub from burning.
Since rubs don’t really penetrate the meat, there isn’t much need to let the meat rest after applying the rub. A few minutes might help the rub adhere better, but beyond that not much is going to change. That makes a rub the go-to option for flavoring meat when you’re in a hurry.
Often a dry rub can do double-duty as a great flavoring ingredient for a marinade; just stir it in.
Rub recipes often include sugar. Sugar brings a sweetness that balances out spice and salt. But sugar also caramelizes, which gives additional flavor – and browning – to cooked meat.
You can buy rubs of all types and flavors. But you can also mix them yourself; most use common herbs and spices that you can easily buy. Not only will that be cheaper, but you can then adjust the recipe to your liking.
- Marinate food in a glass, ceramic or plastic container — not a metal one. The acid can interact with the metal and ruin the flavor of the food.
- While we tend to focus on using marinades and rubs on meat and fish, you can also use them on vegetables. Though you might need to use some oil in order to get a rub to stick to veggies.
On why osmosis has little to do with brining.
(warning: science ahead)
The essence of osmosis is what happens when two liquids are separated by a membrane (usually a cell wall) that has holes large enough for water to pass through but too small for larger molecules. Say, for example, very sugary water on one side and not-very-sugary water on the other; sugar molecules are too large to pass through the membrane. In this situation, in order to equalize the concentration of sugar, water molecules will get pulled from the fresh side to the sugary side, concentrating what sugar exists on the fresh side and diluting the sugar on the other side. An important observation: sugar doesn’t move from the sugary side across the membrane; water moves in the opposite direction.
When we put meat into a brine, we are creating a situation where there is very salty water on the outside of the meat’s cells, and much less salty water inside the cells. If osmosis were happening, we would see water getting pulled out of the cells. But the telltale sign that it’s not osmosis is that the salt actually penetrates into the meat. What we are seeing instead when we brine meat is diffusion of salt into the meat and trapping of water molecules int he meat, both aided by the denaturing effect of a mildly salty solution on proteins.