Food is brined for either flavor or preservation. Concentrations below 0.5% are seasoned perfectly for eating, but are too low to kill most bacteria. Levels above 2% unwind, densify and dry out muscle fibers, leading to the classic cured meat texture. Above 5%, salt concentrations are high enough to kill most bacteria, but the food is way too salty to eat, and has to be washed out or diluted with other ingredients to become palatable. Above 10% meat is being salted for longer-term preservation.
You can either "equilibrium" brine or "gradient" brine. In gradient brining, the meat is placed in a 6% or higher solution which is strong enough to kill bacteria on the meat's surface. Assuming the muscle group remains intact, has not been perforated with needles or knives, and the lymph nodes have been removed or are uninfected, bacterial contamination inside meat is rare. So, an hour or two in a strong brine acts as a disinfectant.
More often, the same brine is used to quickly flavor the meat. For example, a large turkey might be brined in a 6% solution for 24 hours. The salt concentration will run from 6% at the surface, to near zero a half inch below the surface (it could take a week for salt to diffuse all the way to the center of a thick brisket or turkey breast). The meat is then removed from the concentrated brine and cooked. The salt band moves rapidly inward, propelled by heat of cooking. Assuming the surface brined layer is a third of the total turkey volume, this second diffusion step averages out the salt level to around 2%.
Quick and convenient, thought not as uniform or as effective as equilibrium brining at retaining moisture during cooking.
In equilibrium brining, the meat is placed in a low concentration brine until the meat's salt level and the brine's salt level average out1. Which might take a few days or weeks- our calculator estimates the curing time based on the meat's shape and thickness. Often, equilibrium brining is used to prepare a bucket of chicken wings or slices of meat for grilling, which are too gnarly for uniformly applying a dry brine. In that case, use the total weight in the calculator to determine the salt level, but input the thickness of a single piece of meat to estimate brine time. Assuming you frequently agitate the meat in the brine.
A quarter or a half percent salt level is typical for equilibrium brining.
Clicking "dry brine" automatically inserts "0" liquid in the equilibrium brine calculator.
Granulated salt varies greatly in density, depending on the salt crystal shape. Table salt is around 2x as dense as kosher salt, and 3x as dense as some fancy large flaked artisinal sea salts. So best to weigh out your ingredients. However, if you must rely on a measuring cup, that alternative measure is available in the calculator.
If all you are looking for is a standard 6% salt brine, try our fool-proof Archimedes inspired method that works with any shape or mixture of salt crystals.
If you are looking wet cure meat with sodium nitrate powder, read this article first.
In order to maintain the full strength of the gradient brine, make sure the brine volume is a few times large than the meat volume.
1 Do not confuse the brine's salt level with the meat's salt level. Meat consists of actual liquid water juices, water trapped inside cells, and water that is loosely bound to muscle proteins. It also contains some water molecules that are chemical bound to proteins, and are basically immobile. It is the free, mobile water that nourishes bacteria and is most easily salted from the brine. A 1% brine salt level will eventually convert all the free water to 1% salt levels, and some but not all of the fat, immobile water and bone will become slightly salted. So the average salt level in a slice of meat is alway a bit lower than the brine. Perhaps 5-10%. Not a big deal.
Interestingly, when you measure out salt by volume, the dry measuring “cup” is a bit of a fake. The two expensive cups I calibrated are actually 225 cc vs a true 236 cc in volume (even though one was marked as holding 240cc!), because at 225cc, one cup weighs exactly 8 oz. While an accurate cup of water actually should weigh 8.35 oz. They decided to fit our rhyming expectations of "a pint is a pound the world round” in lieu of precision. But only a 4% error.