The Science of Salting from Ancient Rome

Even in Ancient Rome stuffing large fish into terracotta urns, in between generous layers of salt. Salting, as it is called, is a technique for preserving food that lives on and is still carried out using the same methods and processes. For the reasons we are about to discover, salt is actually able to preserve most foodstuffs for months and even years. Why does salt act as a preserve? The salt absorbs the water in the meat.To dehydrate means to remove water, the most precious element of life, comprising the bacteria responsible for decomposition. Which is the exact phenomenon we wish to prevent! By removing water, we prevent bacteria from making our precious food go rotten! For a correct salting process, whatever raw material is involved, we must follow a one important rules. 
First of all, we will use a highly concentrated salt solution. Ideally, we will take the amount of water necessary to completely cover the food and then we will add salt gradually, mixing as we go, until we reach the point where salt starts to deposit on the bottom. This is now a “saturated” solution and therefore perfect for our purpose. Once the food has been immersed in the solution, keep it in the fridge for several days (depending on its type and quantity), closed with a stopper or a hermetic lid.And second rule is choice a right salt. As you know, there are several types of salt: table salt, canning salt and pickling salt.The canning and pickling salt is ideal for canning because  they don’t contain the iodine and anticaking agents that are traditionally added to table salt. Because of its purity and its ability to dissolve easily, canning salt is ideal for pickling vegetables and canning and preserving other foods.