Brine is water with a great deal of salt dissolved in it — in fact, at a higher ratio than even ocean water. The ratio required to be “brine” varies depending on who defines it, but many sources say that it is a salinity greater than 50 parts per thousand. Warm water can hold more slightly more salt than cold water.
The word can also be used as a verb meaning to soak something in a brine.
Brine can occur naturally when ocean water, such as that trapped in tidal pools, evaporates, leaving behind higher salt levels in the remaining water. Brine also occurs underground, and in salt lakes.
Food-grade Brine is made by the cook by adding salt to water. It can be used for pickling and to preserve foods such as vegetables, fish, meat, cheese (such as Feta and Halloumi), etc. It is used for washing cheeses during maturation, and is used in one of the methods for curing olives and curing ham.
For cooking purposes, a good brine should have enough salt in it that a raw (unopened) egg will float in it. That will generally be about 1 cup of salt per gallon of water. Brine can be flavoured with spices, herbs, wine or fruit juice.
You can make meat moister by brining it before cooking. Salt ions pass into cells from the brine water, leaving the brine water slightly less salty. The salt ions in the cells then draw that outside water back to themselves, drawing water into the cells. This helps to weaken the proteins a bit, so that they slacken and coagulate, trapping yet more water inside the coagulation that is happening. By this means, more water gets into the flesh, helping the meat to stay moister during cooking. Brining Turkeys has become somewhat popular in America.
Dry brining is just sprinkling the food item with salt. This term is sometimes used to refer to the process such as that by which sauerkraut is made.
Language Notes
From the Anglo-Saxon word “bryne”, which in terms come from the Anglo-Saxon word “to burn”, “brynnan”. A solution so strong in salt it would burn your eyes.
Sometimes referred to as a “saline solution.”