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 anywhere from 30 minutes to a few days. 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.