Brining
In food processing, brining (to
brine) is treating something with brine or steeping it in brine.
Cooking
Brining is a process similar to marination in which meat or
poultry is soaked in brine before cooking.
Salt is added to cold water in a container, where the meat is soaked usually six to twelve hours. The amount of time needed to brine depends on the size of the meat. More time is needed for a large
turkey compared to a broiler fryer chicken. Similarly with a large roast versus a thin cut of meat.
Brining makes cooked meat moister by hydrating the cells of its muscle tissue before cooking, via the process of osmosis, and by allowing the cells to hold on to the water while they are cooked, via the process of denaturation. The brine surrounding the cells has a higher concentration of salt than the fluid within the cells, but the cell fluid has a higher concentration of other solutes. This leads salt ions to diffuse into the cell, whilst the solutes in the cells cannot diffuse through the cell membranes into the brine. The increased salinity of the cell fluid causes the cell to absorb water from the brine via osmosis. The salt introduced into the cell also denatures its proteins. The proteins coagulate, forming a matrix that traps water molecules and holds them during cooking. This prevents the meat from dehydrating.
In many foods the additional salt is also desirable as a
preservative.
Cheese brining
Some cheeses are periodically washed in brine during their ripening. Not only does the brine carry flavors into the cheese (it might be seasoned with spices or wine), but the salty environment may nurture the growth of the Brevibacterium linens bacteria, which can impart a very pronounced odor and interesting flavor. The same bacteria can also have some effect on cheeses that are simply ripened in humid conditions, like Camembert. Large populations of these "smear bacteria" show up as a sticky orange-red layer on some brine-washed cheeses.