In cooking, brining is a process
similar to marination in which meat is soaked in a salt solution
(the brine) before cooking.
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 enter
the cell via diffusion. 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 which traps water molecules
and holds them during cooking. This prevents the meat from
drying out, or dehydrating.
In many foods the additional salt is also
desirable as a preservative. Note that kosher meats are salted
during the process of koshering so they should not be brined.
Some cheeses are periodically washed in a
saltwater 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 (Limburger) and interesting flavor. The same
bacteria can also have some impact 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