Sometimes it is challenging to surface salting the large cheese, which must be repeated several times. For this reason, the commercial maker brines the cheese as they add the entire cheese into a brine. The brine is a liquid, usually whey from the cheese production that was heavily salted. To make a brine, you need to use a warm whey (or water) and add about 1,5 to 2kg salt to every 5L of whey(or water) or measured in another way 15 grams of salt per 1Kg of cheese. Then cool it down in the refrigerator or cheese cave. The soft cheeses are mostly placed for 4 hours in brine for every KG (500 grams of cheese - 2 hours in brine) 2 Kg of cheese might need 8 hours in brine. The harder chees types need to spend more time in brine per KG, which can be 6 to 8 hours per 1KG of cheese. The salt saturation always needs to be at least 80%.
Soft cheese like feta can be brined with weak brine, but the contact time is longer. However, the hard cheeses are removed from the brine to mature outside.
The brine must be kept in a cool, dry place, and the cheeses need to be flipped, mainly if they should stay a few days in there. A different brine must be used for different cheese types as some fungi are salt-loving(those that deliver blue colour on the blue cheese) and can grow in salt brine and transfer on a cheese that should be white.
Some brines can be made more saturated with salt or the salt can be 10%, 15%, 20%, 25%
Usually, the soft cheeses are salted as salt is mixed with curds. Some hard cheeses are salted before forming.
Other cheeses are surface salted - after draining and removing from the form, the salt is spread on the surface of the cheese. In most cases, this salting process is usually used for fresh soft cheeses as it is challenging to salt the harder cheese variants, although there are exceptions.
Internally salted cheeses use the same amount of salt as any other surface salted cheese - 2% per kg.