"To Brine or Not to Brine?" That is the Question.

Perhaps the most discussed “innovation” of the last few years is the technique of brining a turkey before roasting. Adherents claim that submerging the whole bird in heavily salted water overnight produces moister and more tender meat on the plate.

Does it work?

Yes, to some degree.

Unfortunately, it has drawbacks as well. I am inclined to believe that the results people are getting have more to do with lower roasting temperatures in the new brining recipes and less to do with the brining itself.

When I first read of the technique, I was skeptical because of the junk-science given to explain it.  All were variants on the osmosis theory.

Still, I had to try it.  And to tell you the truth, the results were underwhelming. It seemed to have an unnatural mouth feel – slightly gel-like – as well as a slightly less natural flavor - something akin to the difference between a cooked piece of fresh salmon and a cooked piece of gravlax.

Was it tender and juicy? Well yes, but so were all the turkeys I have cooked since 1980, when I first began cooking proteins with a radically low-temperature technique that I developed as a result of my scientific studies in Molecular Biophysics and Biochemistry.  So, the comparison is unfair. Most people would experience a more dramatic difference from both the brining and the lower roasting temperatures of these new recipes.

How important is the lower roasting temperature?  In the case of fresh birds, I think it is even more important than what the brining contributes. In the case of frozen birds, it is of equal importance.

Every empirical experience in my 35 years of cooking supports the dictum that lower cooking temperature improves the tenderness and juiciness of all proteins. High cooking temperature is the number one affront to protein. And recent rigorous scientific investigation in France conclusively confirms those beliefs.

But before we get to that, let’s examine the original claims that were made for brining, which all seemed to be some variant on osmosis.

Osmosis, in very simple terms, is the passage of water through a semi-permeable membrane until a pressure balance, or homeostasis, occurs. Unsalted water, as is well known, will move toward salt water. Actually, the area of high salt concentration sucks the water through the semi-permeable membrane to the area of lower salt concentration to equalize ionic pressure.

When animal cells are placed in highly-concentrated saline solutions, water is sucked out of the cell by osmosis and the cell shrinks. If the process is unchecked, the cell dies. So the animal cell must always be bathed in a solution that has the same osmotic strength as its own cytoplasm.

(For a fuller explanation, see biologycorner.com). Maintaining this balance is one of the primary functions of our kidneys.

Osmotic theory tells us that immersing animal cells (read: turkey) in a solution whose salt content is much higher that that of the cells themselves will suck water from the flesh and dry it out.  Indeed, long before the scientific age, peoples the world over preserved food by packing it in salt or brine to dry it out. It worked because bacteria have a hard time surviving in dry environments.

 “Well,” said the osmonauts, “even if that is true, the lower pressure in the cell makes the meat more tender.”

This argument confuses the nature of plant cells with the nature of animal cells. Plant cells have a firm wall that allows internal pressure to vary. Flaccid celery sticks, for example, will “firm up” in cold water. Animal cells do not really vary in pressure—they just swell or shrink. As far as animal tissue is concerned, tenderness has everything to do with the structure of the proteins (such as collagen and various other proteins) and the quantity of water trapped in the protein lattices after cooking. The more water trapped the better.

Then the osmonauts tried this: “Well, first the water is sucked out, then the salt ions go into the cells and the water gets sucked back in until there is more water in the cell than you started with.”

But this explanation suspends the laws of physics. Taste will confirm that even after hours of soaking, the brine remains much saltier than the meat. There is only one way cells can move materials in the opposite direction of osmotic pressure, and that is called “active transport.” Unfortunately for the osmonauts’ theory, active transport requires energy and can only be performed by a living organism. 

No, there had to be another explanation that relied on something other than osmosis. Real scientists eventually brought forth an ionic-protein deformation theory. It appears that the salt ions in the brine react with proteins to soften them and help them retain more cellular water upon cooking.

 Here, I’ll turn to the great American scholar of cooking science, Harold McGee. In On Food and Cooking (Scribners, 2004) he writes, “Brining has two initial effects. First, salt disrupts the structure of the muscle filaments. A 3 percent salt solution (2 tablespoons per quart/30 gm. per liter) dissolves parts of the protein structure that supports the contracting filaments themselves.

"Second, the interactions of salt and proteins result in a greater water-holding capacity in the muscle cells, which then absorb water from the brine…The meat’s weight increases by 10% or more…In addition, the dissolved protein filaments can’t coagulate into the normally dense aggregates, so the cooked meat seems more tender.” (pages 155-156)

While McGee describes what is happening, he doesn’t really explain how it is happening on a chemical/molecular level. Is it a reversible or non-reversible “field-effect?” Or do the ions actually "complex" with the proteins? A recent study in Denmark on the movements of sodium ions in pork loin during brining seems to confirm that the salt ions complex with the proteins of the meat.  

In addition, research indicates that the concentration of the brine has an effect on the degree of swelling. NOTE: I will spare readers further academic citations for these studies. But if you're interested, post a comment to that effect and I'll provide them.

 ven more interesting is an Ohio State study that seems to prove that there is something special about turkey protein as far as its ability to trap water in the wet-curing process. Sausages, to which turkey protein was added, retained more water after wet-curing than sausages made of pork alone. 

Wet-curing does seem to have, in certain cases, the opposite effect of dry-curing, which definitely shrinks proteins. McGee himself explains that dry-curing “…makes the tissue denser and more concentrated.” (page 174)

French chemist Hervé This (pronounced Teess)—known as the father of molecular gastronomy—has conducted important research on dry salting. The results seem to prove that when dry salt is added to meat for relatively short time periods (as when you heavily salt a steak before searing it), the salt does not migrate through the meat

In his indispensable 2006 book, Molecular Gastronomy, This explains, “We salted the meat before and after cooking, measuring the loss of juice and, most importantly, analyzing the pieces of cooked meat with a scanning electron microscope and a device for detecting chemical elements by means of X-rays.” (page 52) In fact, “There is no disgorging of liquid, even though the meat has been coated with salt.” (page 51)

Furthermore, “X-analysis reveals the presence of various chemical elements (notably sodium and chlorine in the case of kitchen salt) making it possible to determine whether the salt diffuses through the meat.  Again, the answer is clear: Rather than penetrating to the center, it actually passes out of the meat during cooking.” (page 52)

So what is really going on here?  It would seem that the salt behaves quite differently when it is applied dry to meat than when it is applied in brine of specific concentrations.

In the next installment of this post, we’ll move on from theory to explore the gustatory effects of brining.

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