Standards: Moisture 55%; Fat 22%
Traditional Procedure (Structured Feta)
- Standardize milk to P/F = 0.90 and pasteurize (72C, 16 S or 62C, 30 min.). The Greeks prefer a perfectly white smooth product made from sheep's milk. Goat's milk also produces a white cheese. If desired, a smoother cows' milk product can be made by selecting milk with higher fat contents in the range of 5.5 to 6.0%. The undesirable cream colour of cows' milk can be removed by treating the milk with 0.03 - 0.04% titanium dioxide. Titanium dioxide is diluted with 10x its weight of warm water and added to the milk before renneting. Whiter cheese can also be produced from cows' milk by homogenizing the milk.
- Adjust temperature to 30C. Add 3% of S. lactis and/or S. cremoris starter. and 3 g lipase per 1,000 kg milk. Ripen for about an hour until TA increases by at least 0.05% and pH is 6.6 - 6.5.
- Measure 120 ml rennet per 1,000 kg milk. Dilute the rennet with 10 volumes of water and add the mixture to the milk. Agitate for 3 minutes and then allow milk to set. Setting time should be 45 - 60 min.
- Cut the curd using Omega" (12.8 mm knives) knives.
- Stir gently for 20 min.
- Dip curd and whey into rectangular forms on a drain table.
- Drain for two hours at 30C, then place the curd in a room at 18C and 85% RH. In the absence of such a room, cover the cheese with a clean cloth and store overnight at room temperature and humidity.
- When the pH is 4.7, 20 - 24 hrs. after adding culture, take the cheese out of the hoops, weigh to the nearest 0.1 kg, and cut into 10 cm. cubes.
- The required salt is 50 g of salt per kg of cheese. Weigh all the salt for all the cheese at once and distribute it uniformly by rubbing salt on all sides of the cheese surfaces. Place the cheese in 1 l plastic tubs with the lids partially open to allow some drying off of the cheese, and store at room temperature for 24 h. An alternative process, is to dry off for 1 day under a damp cloth and then store in barrels or canisters for up to 30 days at 8 to 10C. After this ripening period, the cheese may be consumed as is or stored in 8% brine.
- Add sufficient 8% brine to cover the cheese, and ripen at 8-10C for up to 30 days. Subsequently store at 2-4C until consumed. The brine solution should contain 0.06% calcium chloride and sufficient acetic acid (vinegar) to adjust the pH to 4.6.
Typically, Feta cheese is packaged and distributed to retailers and restaurants in one of four forms: (1) Cubes and brine in small tubs; (2) Crumbled product in a gas flushed package (nitrogen) ready for addition to salads; (3) Vacuum packed blocks; (4) Bulk shipments of cubes in large containers.
Process and Quality Control Notes
- At least 0.05 increase in TA before renneting
- pH 4.7 before surface salting
- Yeast and mould counts are the best indicators of hygienic problems. The low pH keeps bacterial spoilage to a minimum.
- A comfortable best before date is 6 months after manufacture. Good manufacturing practice and storage can achieve 12 months shelf life.
UF Procedure (Cast Feta)
- Standardize milk to P/F = 0.80.
- Ultrafilter until retentate is 40% solids.
- Add 3% S. lactis culture and 250 ml rennet/1,000 kg of precheese.
- Quickly pour into 1 l plastic containers (3/4 full). Cover and allow to ripen to pH 4.8 (18 - 24 hrs.).
- Add salt (3% of weight of cheese) to surface.
- Store at 18C for at least 1 week before consumption.