Before going straight to the explanation of the cheese elaboration process, it is necessary to clarify that we speak about a global generic process because all the cheeses aren’t made all the same.

What is cheese and how is it made?
Cheese is a fresh or mature product obtained by curdling and parting of all of these components: milk, cream, totally or partially skimmed milk, butter serum.

Cheese Elaboration process
Reception and pre-treatment of milk
When receiving the milk, it is necessary to eliminate all solid impurities that could come from the breeding stock. Once it is purified, the milk homogenizes if we want to give it a special fat content. In order to do that, we use a machine that separates the fat.
In the case we don’t use the homogenization process, we speak of whole milk.
Later, if the milk hasn’t been through the making process at this moment, we cool it at 3 to 4 degrees (optimal temperature for preservation).
 
Thermal treatment of the milk
Before starting the elaboration, with freshly received or refrigerated milk, we need to heat it up from 70 to 80ºC during 15 to 40 seconds. This process is called pasteurization. The aim of this treatment is to eliminate all pathogenic germs from the milk.
Raw milk cheese is exquisite and can be consumed without any problem if it has more than 60 days maturation or if the milk comes from a very clean farm. It is important to stretch out that before milk was not heated because pasteurization did not exist.

Tank filling and leaven addition
Once we have treated milk or not, we pour it in a tank and heat it up to 25-30ºC and then add lactic bacteria, leaven and mildew which role is to bring aroma and taste throughout the maturation process.

Curdling
Then we add rennet (extract obtained from the cow’s stomach curds or from plants) and it is from there that the milk transforms itself because the casein (the protein most present in milk) is curdled at 30-32ºC, including a good part of fat and other components.
The other form of curdling is done through the acidification of milk because if we leave the milk to room temperature, its acidity will rise little by little until obtaining curd milk. Thanks to this technique, we can make Cottage cheese.

Cutting
When the curdling is over, we have a great mass of milk. The latter is cut with blades, the aim being to cut the milky mass: depending if we need big or small grains for the cheese we want to make. Generally, a more humid cheese is made by bigger grain that acts like a « sponge ». It is also during this process that we extract the whey.

Heating
Once the paste is cut and has liberated the whey, it is heated to 30-40ºC while it is shaken so the grains stay separated. When the grains are heated even more, whey is also liberated. Depending on what temperature we heat the paste; we obtain soft, semi-cooked and cooked paste. 

Pressing
After the heating phase, we proceed to the molds filling (container that give the cheese its form and size).The molds can be submitted or not to an external pressing.
Pressing helps getting out more whey and giving the cheese a more compact form. We then speak about pressed paste cheese or non pressed cheese.

Salting
Once the cheese is pressed, we need to salt tit. We can either do that on a dried cheese or put the salt directly in the mass with water.
 
Maturation
Maturation is the last phase of the elaboration and it can last from a few hours to a few months. During this phase, many aromas and tastes are bursting out.
Maturation is done in very special places where the temperature and humidity are scheduled for each cheese. These cellars can also be natural ones (as for the Cabrales cheese or the Picon-Tresvijo).
 
Throughout the maturation, the cheese looses progressively its humidity thanks to evaporation. This causes a reduction of its weight and a progressive growth of its dry matter content. This means that if for example we have a 1 kg of cheese the first day, it will be composed of 450 gr of fat and 450 of water. After maturation, this cheese will only weight 900 gr and its composition will be 450 gr of dry matter and 450 gr of water.
Depending on its time maturation, we speak of fresh cheese, tend, semi dry, dry and mature cheese.

The cheese elaboration has surely been discovered by many different communities at the same time. Ewes were domesticated more than 12 000 years ago and in the Ancient Egypt cows were domesticated for their milk. It would be logical then to think that they knew how to make cheese.
The milk was preserved in skin, wood or ceramic containers; but as it was difficult to keep them clean, the milk was curdling very quickly. The next step was to extract the milk serum to elaborate a fresh cheese, without any rennet, with a strong and acid flavour. The legend says that an Arabic shepherd, coming from a very long journey in the desert, had put ewe’s milk in a bag made of animal tripes and when he opened it he found the milk curdled, with a solid form.
The Romans integrated cheese in their alimentary diet with thyme, pepper, gable and other dry fruits, and when they installed their camp, they were making cheese.

All the antiquity is full of fresh and curdled cheese references. In the Antique Greece, people didn’t eat cheese alone but with flour, honey, oil and dried fruits; we can actually still find cooking recipes that dates back to this time.
The word cheese comes from the Greek  fornos  and from there comes the French word fromage, fortmatge in Catalan and formaggio in Italian. The latin word caseus brought the word cheese in English because the caseine is the principal albuminoidal of the milk and cheese.

During the Middle Age, the religious orders have transformed themselves in important places for the farming activities. The cheese has gained great importance during the large times of abstention and the religious have developped a lot of different types of cheeses.

Thanks to the quick development of commerce and the rise of town population, cheese has started to be commercialized and became important for the oversee after the discovery of the New World.
 
At the beginning, people used raw milk in the 1850’s, but the biologist Louis Pasteur discovered pasteurization which has changed the way of making cheese.

People started to mix different cheeses until obtaining a homogenous product that didn’t have any bad microorganisms.

In Spain, people developed ewe’s and goat’s cheese but much later cow’s milk. In other countries, cheese was made with buffalo’s milk. 
Comsumption of cheese has really started in France, and then in Switzerland, in Italy and in Spain.