Aging or preserving cheese in brine is common with Aegean Sea originated cheeses such as φέτα/Feta/Fetta, and Halloumi where, depending upon recipe, they can be stored up to 12 months.

Brine Concentration
Brines used to store these cheeses are normally 16% salt, the minimum for minimising unwanted bacteria growth.

Higher % salt could be used, but is not required and will make the cheese taste very salty.

Lower % salt will result in a more immediately edible cheese but with shorter shelf life due to unwanted bacteria growth.

Brine Fluid
Brine are normally made using water as the base fluid, the exception is brine for preserving cheese. Here the options are:  water, half water and half whey, or all whey from your cheese making. Using whey gives the brine a higher calcium component and a lower pH, reducing the need for the addition of Calcium Chloride and vinegar in newly made brine. The use of whey also makes the brine preserved cheese more flavourful. Many people who use whey for the base of their brine boil it first.

Ways To Reduce The Salty Taste
16% brine preserved cheese, if used in a cooking recipe is fine, but if eaten directly is to most people, very salty to the taste. Methods to reduce the salty taste are

1. Remove cheese from brine and soak in fresh water or milk for up to 1 hour before consuming.
2. Instead of all non iodised salt (NaCl), use up to 50% Potassium Chloride salt (KCl) also known as LO Salt.
3. Try the 7% Low salt with added Calcium Chloride recipe below.

Understanding Brines Used To Preserve Cheese
Many cheese making procedures, when using brine for salting, call for brine between 18 & 23% salt. This is because the range of brine resistant spoilage bacteria that can survive in brine increases significantly at less than 16% salt. Weak brines are notorious sources of contamination and thus if used, should be disposed of after using and not re-used. Weak brines also result in less moisture loss from the cheese surface, resulting in several possible defects:

• The body of the cheese will have a higher water content and thus be weaker and softer than desired.

• Soft or swollen cheese and a slimy, greasy, or “melting” surface of the newly formed cheese.

• Less salt in the cheese, causing the acidity to continue to develop, resulting in higher acidity (lower pH). This will favour the growth of spoilage organisms.  Aged type cheeses may develop sticky and discoloured rind patches, varying from yellow to bright orange, red or brown. Also, the surface will be prone to show growths of the black or grey mucor moulds (poille de chat) which look like fine black cat hairs

Brines above 23% salt increases the risk that moisture will be lost too rapidly from the surface of the cheese. This can result in a very dehydrated layer which may hinder or reduce the further uptake of salt into the body of the cheese to reach the correct % salt in cheese, depending on the cheese type.However, some ‘home’ cheese making recipes call for brining with saturated (26% salt at 15°C) brines. This is because:

• Saturated brines are easier to make and maintain.

• They provide an easy standard against which future cheese making batches can be measured.

Freshly made brines will exhibit what is known as ‘cat ion exchange’ whereby the calcium and hydrogen ions in the cheese surface will transfer to the brine until the brine and cheese reach a balance. This transfer will result in the casein in the cheese surface to absorb water and swell leaving a soft slimy layer that in aged cheeses leads to rind rot during aging. To mitigate this transfer:

• Acidify the new brine to a pH of ~5.0, or roughly the same pH as the cheese. The most common way to do this is by adding white vinegar or citric acid. Typically 1 teaspoon per litre of water of standard 5% vinegar.

• Add ~0.1% food grade Calcium Chloride (CaCl2) to the brine.

Brine Table

• This table is based on the water temp for your brine being at 15°C.

• The table only goes to 26% as at 26.395% brine is fully saturated and any additional salt will not dissolve.

• % weight of brine means % of total brine including salt - i.e. if you put dissolve 1 kg of salt in 5 litres of water, the brine will weigh 6 kg and you will have 1/6 = 16.7% brine. 

E.g. To make 5 litres of 16% brine the table below says 0.1905 kg salt/litre water for ~16% brine. Therefore, combine 5 litres water and 5 x 0.1905 = 0.9525 kg salt and stir until dissolved.

% Salt Kg        Salt / Litre Water
     0                            0
     2                            0.0204
     4                            0.0417
     6                            0.0638
     8                            0.0870
    10                           0.1111
    12                           0.1364
    14                           0.1628
    16                           0.1905
    18                           0.2195
    20                           0.2500
    22                           0.2820
    24                           0.3158
    26                           0.3513
 

This information about brining has been collated and adapted from the following sources – Icelandic Sheep Breeders of North America Vol6, No. 2 Spring 2002 and www.Cheeseforum.org