>>10581628>>10581655First, as osmosis pulls in the brine and any flavoring you mix with the salt water, it also pulls in water until there's an equilibrium of moisture throughout the bird. The meat becomes saturated initially, so that a brined piece of poultry going into the oven does so with an initial moisture content both higher and more universally distributed throughout than an unbrined fowl. You can afford to lose more moisture because it's starting with more moisture right out of the gate.
Second, and this is where the science comes in, brining lessons moisture loss during cooking by denaturing the food ahead of time. See, anything that causes loss of moisture in the meat, be it contact with air, salt, or heat, can be lumped together as denaturing. The salinity of the brine causes some initial denaturing of the flesh, but does so in a controlled way that allows moisture to recover. By the time it's cooking, some of the denaturing that would have been caused by heat has already been done, and has already been mitigated. As a result the final product is juicier and more tender.
It's kind of like dry aging a steak, in that regard. You kind of pre-traumatize the food on your terms to uncoordinated trauma happening during cooking. Which is not at all a good metaphor, really, just the best I can do on short notice.
And that's why brining and marinading are different.
