Brining is the addition of food to salty liquid. At a lower concentration of salt the fluid penetrates most food, but especially meat. This lower level brining results in added moisture. It is particularly popular for poultry before it goes into roast. The difference in texture is very noticeable and it doesn’t necessarily introduce any extra saltiness to the meat.Adding something less than sea water strength brine to chicken works well. Sea water is about 3.5% dry salt to water, or 7 level teaspoons to 1 litre of water, about the level needed for brining. This measure is used with fine tablesalt. Brining should be for about 1 hour per lb, not exceeding 12 hours.
The more concentrated the brine solution the closer it becomes to matching or exceeding the balance of the cells osmotic weight. Osmotic balance indicates which way fluid will flow through the cell wall. If the inside is lower weight the fluid will flow outwards. This is the level at which brining can then be used for preservation purposes. The amount of salt would be about twice that of the above brine and the meat would be stored in the solution for days rather than hours.
Salt can vary a lot in weight to measured volume. This be double between fine and coarse sea salt. The only accurate way to do this is by aiming for a target salinity. A floating measure called a brinometer is used for this, which looks like the specific gravity measure for beer.