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Water and food

Brine and salting

Grams of salt for a brine of a given strength, with approximate total mass, density and volume.

L

In litres or kilograms: 1 L of water weighs practically 1 kg.

Most recipes and technical tables use % by weight of the brine. Some say “50 g per litre” or “5 % of the water”: that is relative to the water.

%

As a guide: vegetable fermentation 2-5 %; pickles 5 %; olives 8-10 %; saturated brine about 26 %.

Result

Salt
— g
Mass of brine
— kg
Strength by weight of the brine
— %
Salt per litre of water
— g/L
Approximate density at 20 °C
— kg/L
Approximate volume of brine
— L

How it is calculated

By weight of the brine: salt = water × c ÷ (100 − c). Relative to the water: salt = water × c ÷ 100. Total mass = water + salt.

Example. A 5 % brine with 1 L of water: 1000 g × 5 ÷ 95 = 52.6 g of salt; total mass 1.053 kg. That is not the same as 50 g per litre, which gives 50 ÷ 1050 = 4.76 %.

Density. Interpolated from the table of sodium chloride solutions at 20 °C (CRC Handbook): 1 % 1.005; 5 % 1.034; 10 % 1.071; 15 % 1.109; 20 % 1.148; 26 % 1.197 kg/L. Volume = mass ÷ density: at 5 %, 1.053 ÷ 1.034 = 1.02 L.

Keep in mind

  • Weigh the salt: a level tablespoon weighs between 12 and 20 g depending on the grain, and the error shows in weak brines.
  • Use salt without iodine or anti-caking agents for fermenting and pickling: they cloud the brine and can slow fermentation.
  • Brine alone does not make a preserve of low-acid food safe: botulism risk depends on acidity (pH < 4.6), salt, temperature and time. Follow a tested procedure, keep food submerged and discard any that smells bad, foams abnormally or has a bulging lid.
  • Density lets you check a brine with a hydrometer or by weighing one litre. The floating-egg test is imprecise: it depends on how fresh the egg is.

See also

More tools in “Water and food”