There are many different ways we can treat meat before (and after) cooking to impart a huge variety of flavors, but how often have you considered the principles at work? You brine or salt a turkey for Thanksgiving or marinate a steak for the grill without questioning the recipes.
Sometimes the results are disappointing — dry meat even though you marinated for 24 hours, tough bites after salting, or perhaps mushy poultry skin. What happened? Why do some recipes seem to work, and others don’t? This article will break down the chemistry of salt and acids and the effect on the muscle tissue in meat so your meat can be treated right every time.
A brine is defined as a solution of salt and water with a high concentration of salt. This is most often used for lean meats such as pork, chicken, or fish; you can also employ this method with some vegetables. We’ll save the vegetable discussion for a later article and just focus on the meat.
Balance is sought naturally, so when a piece of meat (say, chicken for illustration) is submerged in a brine, there is a high concentration of salt outside the chicken, and a low concentration inside the chicken. Thus, salt will naturally diffuse (move through) the cell walls of the muscle as an equilibrium concentration is sought. Since the salt is dissolved in water, water will also move through (called osmosis). During this process, the meat picks up water weight. (In fact, you have likely felt this yourself if you eat high-salt, heavily processed foods for a day. Your body will retain the water you drink, and you bloat.)
The concentration of salt matters here. If your brine is too salty, then water will actually be drawn out of the meat, which is undesirable. Too little salt, and the diffusion rate is too slow to be effective.
In addition to the diffusion and osmosis balancing that occurs during brining that moves the salt into the meat, there is another chemical effect happening. Salt is ionic; recall from your high school chemistry class that table salt is composed of sodium and chlorine ions, bound together with an ionic bond. That bond is broken when salt is dissolved in water, so we have positively charged sodium ions and negatively charged chlorine ions in solution.
As these ions penetrate the chicken, the proteins are forced to rearrange themselves (proteins have charges too, on various locations of their structure) to accommodate these new ions. The rearrangement of the proteins leaves gaps that water fills, so the meat holds onto more water. In addition, the rearrangement weakens the structural integrity of the proteins, which reduces toughness, leading to more tender, juicy cooked meat.
Example recipe: Grilled Pork Chops
- 3 tbsp salt
- 3 tbsp sugar. Note: You can omit this, but the sugar will actually help the pork brown nicely, and it doesn’t impart a flavor.
- 4-12 oz. bone-in pork chops, about 1.5″ thick. (Boneless works well too, but you’ll have to watch them carefully on the grill.)
- Your favorite spice rub, or pepper to taste.
- Dissolve sugar and salt in 1.5 quarts cold water in a large container.
- Submerge pork chops in the brine, cover with plastic wrap, and refrigerate between 30 minutes and one hour. (This is important. You want the brine to have plenty of time to penetrate, but not so long you make the meat too salty.)
- Remove the pork chops from the brine, pat dry with paper towels, and rub with your favorite spice rub. (I like a good Cajun one.)
- Get your grill going until hot (specifics vary according to whether you’re using a gas or charcoal grill. If charcoal, make sure you use lump charcoal instead of briquettes, and don’t use lighter fluid. That will impart a gross taste.)
- Clean and oil the grate. Place chops on the hotter side of the grill and cook covered until browned on both sides (4-8 minutes. Check frequently, but not too frequently or you’ll lose heat too rapidly.)
- Move the chops to the cooler side and continue to cook, turning once, until the meat registers 145F (7-9 more minutes).
- Pull the chops off the grill, transfer to platter, tent with foil, and let rest for 5-10 minutes, then enjoy.
Salting (or Dry Brining)
What happens if we take the water out of the brine? Why would we want to do that?
While you can use a wet brine and still get a crispy-skinned turkey or chicken, I’ve found more reliable results with salting when the crispiness of the skin is important to me.
Here, we simply rub an appropriate amount of salt directly onto the meat. (I recommend kosher salt, or at least salt that isn’t iodized. I’ll address salt in detail in a future article.)
The mechanism is similar, but this time we are essentially using the salt to create a brine with the meat’s own juices. By the same balance principles discussed above, the salt will diffuse from an area of high concentration to one of low concentration. However, because there is little water on the surface, water will begin to be drawn out of the meat. If you cook meat too soon after you salt, this moisture that has been pulled to the surface will evaporate, and you’ll end up with a sad, dry piece of poultry.
As time passes, the surface becomes a high concentrated brine from the juices pulled to the surface, so the salt will continue to diffuse deeper into the meat. As the salt penetrates the meat, the surface moisture is drawn back into the meat. With salting, there is no net gain or loss of moisture, unlike brining where we increase the water weight of the meat.
Salting will result in a drier surface than brining as the juices follow the salt back into the meat, which yields that crispy skin and moist meat we seek with chicken and other poultry in particular.
Example recipe: Crisp Roast Chicken
This recipe will also make use of baking powder — the same ingredient we used to make crispy chicken wings. The salting takes 12-24 hours. I salt the night before I want to cook the chicken. This is a great recipe to impress the family on a Sunday dinner.
- 1 3.5-4 lb. whole chicken, giblets set aside or discarded.
- 1.5 tsp salt (noniodized)
- 1 tsp baking powder
- 1/2 tsp pepper
- Carefully loosen the skin covering the breasts and thighs.
- Using a metal skewer or the tip of a sharp knife, poke 15-20 holes in the fat deposits on top of the breasts and thighs.
- Combine the salt, pepper, and baking powder in a small bowl.
- Pat the chicken dry with paper towels.
- Sprinkle the salt mixture evenly all over the chicken, and rub in with your (clean) hands.
- Set the chicken breast-side up in a V-rack set in a roasting pan or rimmed backing sheet and refrigerate uncovered for 12-24 hours.
- Set the oven rack at the lowest position and heat the oven to 450F.
- Poke 20 holes about 1.5″ apart into a 16″x12″ piece of foil, and place the foil loosely in the roasting pan.
- Flip the chicken breast side down and set the V-rack in the prepared pan on top of the foil.
- Roast the chicken for 25 minutes, then remove the pan from the oven and (carefully!) rotate the chicken breast side up. I use either a really long pair of sturdy tongs to do it, or you can use two large paper towel wads and your hands. Just be careful not to touch the hot pan.
- Continue to roast until the breast registers 135F (15-25 minutes).
- Increase oven temperature to 500F. Continue to roast until the skin is brown and crisp and the breast registers 160F (10-20 minutes). Transfer the chicken to a carving board and let it rest for 20 minutes, then serve.
Perhaps you’re used to marinating meat in a store-bought salad dressing, or some other bottled concoction. You’ve probably been disappointed with the results. Why is that?
A marinade aims to impart flavor in addition to the salt, but what flavors we choose and the components of the marinade can make or break a dish. The salt will perform the same role as it has in a brine (dry or wet). Sometimes the flavors seem to only hang out at the surface; this is because most herbs and spices are not water-soluble, which means they won’t get carried into the meat through osmosis the way the salt will. Glutamates are water-soluble and can impart an umami flavor deep into the meat. Soy sauce and MSG are some examples, which is why many packaged foods can seem so “flavorful”.
Marinades almost always have a large oil component (olive oil works well here if you’re trying to avoid the vegetable oils) to help handle our non-water-soluble flavors. Many of these flavors are fat soluble (see the butter article as well), so the oil will help dissolve those flavors. In addition, the oil helps these flavors cling to the surface of the meat and penetrate the fat.
One component we see often in marinades but don’t really want much of is acid, such as lemon juice or vinegars. Why not? Acid dissolves proteins, which tenderizes meat, right?
Yes, that is partially true. The acid only dissolves proteins at the surface, which will end up just making your meat mushy. Why?
Protein molecules contain both positive and negative charges, typically more of one than the other. This imbalance causes the proteins to repel each other. If the electrical charges balance out, we call this the isoelectric point, and the proteins will pack closer together, which squeezes out liquid, and makes your meat tougher. This is the opposite of what we want. Acids push the meat and marinade towards that isoelectric point, which occurs in muscle at a pH of 5.2. Most meats start out slightly acidic, so too much acid pushes our dinner to that undesirable point.
If we are to use any acids, we must keep it at a very low concentration, or use acidic marinades for only a brief time period.
Example Recipe: Spanish-style Garlic Shrimp (Serves 4-6)
- 14 peeled garlic cloves
- 1 lb. large shrimp (26-30/lb), peeled, deveined, tails removed
- 1/2 c. olive oil
- 1/2 tsp salt
- 1 bay leaf
- 1 2″ piece of mild dried chile (if desired), chopped roughly
- 1.5 tsp. sherry vinegar (you can substitute white wine vinegar if desired)
- 1 tbsp. minced fresh parsley
- Mince 2 garlic cloves and toss with 2 tbsp olive oil, salt, and shrimp in a medium bowl. Let the shrimp marinate at room temperature for 30 minutes.
- Smash 4 garlic cloves with the flat of a chef’s knife.
- Heat the smashed garlic with the remaining 6 tbsp olive oil in a 12″ skillet over medium heat, stirring occasionally, until the garlic is a light golden brown (4-7 minutes). Remove the pan from heat and cool to room temperature, then discard smashed garlic.
- Thinly slice the remaining 8 garlic cloves. Return the skillet with the garlic oil you just made to low heat. Add sliced garlic, bay leaf, and chile if using.
- Cook until garlic is tender but not browned.
- Increase the heat to a medium-low and add the shrimp with the marinade to the pan in a single layer.
- Cook the shrimp without disturbing it for about 2 minutes. The oil will begin to gently bubble.
- Flip the shrimp and continue to cook until almost done, another 2 minutes.
- Increase the heat to medium-high and add vinegar and parsley. Cook while stirring well another 15-20 seconds to finish the shrimp, and serve.
Understanding some of the chemistry behind recipes makes for well-informed cooks and predictably good results. As a summary, use brines and salting for a period of time mainly for lean meats, such as poultry. Marinades can be done with just about any type of meat, but one should take note of the recipe for proper marinade components and marinating time. Marinating rarely needs to be done longer than an hour or so.
- McGee, Harold (2004). The Science And Lore Of The Kitchen. Scribner. pp. 155–156. ISBN 978-0-684-80001-1.
- Crosby, Guy (2012). The Science of Good Cooking. America’s test Kitchen. ISBN: 978-1-933615-98-1
- Oreskovich, D.C., Bechtel, P.J., KcKeith, F.K., Novakofski, J., and Basgall, E.J. “Marinade pH Affects Textural Properties of Beef.”.Journal of Food Science, 57 (1992). pp. 305-311.
- Yusop, S.M., O’Sullivan, M.G., Kerry, J.F., Kerry, J.P. “Effect of Marinating Time and Low pH on Marinade Performance and Sensory Acceptability of Poultry Meat”. Meat Science 85 (2010). pp. 657-663.
- Offer, G. and Trinick, J. “On the Mechanism of Water Holding in Meat: The Swelling and Shrinking of Myofibrils.” Meat Science 8 (1983) pp. 245-281
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