In this article there is everything about feta cheese production. In most cheese factories the same steps are followed for the preparation of the most basic cheese products.
First, the milk is transported to the unit by the producers and the collection and refrigeration stations which have been installed in selected locations in the wider area. The transfer takes place at a temperature 4ΟC in stainless steel tanks, which meet the hygiene and safety standards of milk. With pumps it enters inside the unit and is temporarily stored in receiving tanks at a temperature of 4 ° C. Upon receipt of the milk in the unit, quality control is necessary, which includes the following stages:
- Temperature control
- Acidity control
- Antibiotic testing
- Content of fat, protein, lactose, solid residue and non-fat solid residue.
Feta Production Process
The production process of feta is as follows:
The milk that will be used for the cheese making is required to have the lowest possible microbial load and body cells, for this the milking must be done in the appropriate ways and the cold chain (4οC) must be maintained.
Pasteurization is usually achieved in small units with the open type method, in the same boiler that will later coagulate if no clamp is used. The time is 10 minutes at 68oC.
Add rennet – crops and CaCl2
After pasteurization, the milk is allowed to cool to 34oC and rennet and cultures are added. The rennet can be in dry form lyophilized with a coagulation strength of about 1: 115,000. Microbial cultures are also commonly used in yogurt (L. Bulgaricus, S. Thermophilus).Calcium chloride (CaCl2) is added in order to enrich the milk with calcium resulting in greater calcium retention in the gel, greater ability to reorganize peptides after casein cleavage and higher yield in cheese.
The division-cutting is usually done manually with the help of a cheese cutter in cubes of 2 cm3, after the arrival of about 35 minutes from the moment of the addition of the rennet, after a solid body (gel) is created.
Installation in molds
After cutting, the curd is added, with great care to make it evenly distributed in the molds, with the help of a stainless steel utensil.
The cheese mass in the molds is allowed to drain for 24 hours. The largest amount of whey is eliminated in the first 2 hours. After the rennet is added and as soon as we see that the milk has coagulated, we cut the curd into small square pieces in order to better separate the curd from the whey. After cutting it, it enters molds-molds to take shape and also to drain its liquids.
The whey is removed with a pump in stainless steel pipes, while the curd is placed in molds with pressure to drain. Only 50% of the solids present in milk are incorporated into cheese. The rest (90% of lactose, 20% of protein and 10% of fat) remain in whey. There the cheese undergoes its first salting with coarse salt. After a few hours, the liquid salting enters the brine.
The cheese is molded, and placed in simple tins in layers between which they were salted by hand on the surfaces, and left at room temperature (16-18οC) until the pH drops to 4.6. At the end of the process, brine is placed in the tins.
Temperature and pH are the main factors that affect the rate of salt absorption by the cheese and consequently the rate of moisture loss. The higher the temperature, the higher the absorption. For these reasons the cheese is placed in containers to which brine has been added, transferred to a maturation chamber, at a temperature of 22-25oC for about 10 days.
After 10 days it is transferred to the refrigerators where it will remain for another 50 days at 2 ° C. In total, the ripening of the feta lasts 60 days in order to acquire the necessary organoleptic ingredients that give it its characteristic taste and aroma, but also to completely eliminate the risk of developing pathogenic microorganisms that were not killed during the pasteurization process.
The cheese is required by law to mature for at least 2 months from the time of coagulation, in order to kill at low pH the potential pathogens (but not their spores). This maturation takes place at 4oC. The ripening, among other things, aims to give the cheese the necessary organoleptic characteristics that distinguish it, such as aromas and taste.
The feta cheese then matures for at least 2 months in wooden barrels or metal containers in brine so that it is safe for consumption and is promoted in the local markets. The maximum moisture of the feta is 56%, the minimum dry fat content is 43% and the its pH ranges from 4.4 to 4.6.