Feta Cheese Production

Feta and Feta-Style Cheese Categories

Traditional Feta Production

1. Milk preparation

Traditional Greek feta uses sheep milk (often blended with up to 30% goat milk). Milk is HTST pasteurised at 72°C/15s, then cooled to ~32–34°C cheesemaking temperature.

2. Inoculation

Mesophilic or thermophilic starter culture is added depending on the producer. Streptococcus thermophilus with Lactobacillus delbrueckii subsp. bulgaricus is common for traditional feta.

3. Coagulation

Calcium chloride at 10–20 g/100 L and rennet at 20–30 mL/100 L are added. Coagulation takes 45–60 minutes at 32–34°C.

4. Cutting and curd handling

The coagulum is cut into large pieces (~25 mm cubes) and allowed to settle with minimal stirring. Whey is drained partially and the curd is transferred to perforated moulds. No cooking step — the cheese retains high moisture.

5. Pressing and forming

Curd is allowed to drain in moulds under its own weight for 12–24 hours, with periodic turning. Final pressed cheese has approximately 55% moisture and 21–24% fat.

6. Dry salting

Pressed cheese blocks are salted with dry salt at 3–4% by weight, applied to all surfaces. This draws additional whey out and forms the surface salt layer that will equilibrate during brine maturation.

7. Brine maturation

Cheeses are transferred to brine tanks at 8–12% NaCl, 12–15°C, and matured for a minimum of 2 months (PDO requirement) up to 6–12 months for premium product. During this time:

• Salt equilibrates between cheese and brine to 2–4% in the final cheese
• Mild proteolysis develops the characteristic salty-tangy flavour
• Texture transitions from firm pressed curd to crumbly-creamy

Ultrafiltration (UF) Feta Production

UF feta uses membrane filtration to concentrate the milk to cheese composition before coagulation, fundamentally changing the process economics.

The UF advantage

In traditional feta, whey carries away ~50% of the protein (mainly whey proteins) as a loss. In UF feta, ultrafiltration retains essentially 100% of the protein in the retentate, increasing yield by 15–25%.

The UF process

1. Standardisation — milk is standardised to target fat:protein ratio
2. Pasteurisation — HTST 72°C/15s or higher
3. Ultrafiltration — milk is concentrated to ~5:1 (volume reduction) using polymeric or ceramic UF membranes (10–20 kDa cutoff). The retentate has ~22% protein, ~22% fat, ~50% total solids.
4. Direct packing — the UF retentate is dosed with starter culture and rennet, then immediately packed into the final retail containers. Coagulation happens in-pack.
5. In-pack ripening — containers are held at 25–30°C for 4–6 hours for coagulation, then transferred to cold maturation at 8–12°C.
6. Brine addition — for traditional appearance, brine is added to the containers after initial coagulation.

UF feta retains whey proteins in the curd, giving slightly different texture and flavour than traditional feta. EU regulations distinguish between traditional and UF processes for PDO purposes.

Yield Comparison

Brine Maturation — The Critical Process

Whether traditional or UF, brine maturation determines final feta character:

• Brine concentration — typically 8–12% NaCl for the maturation phase, sometimes higher (14–18%) for long-term storage
• Brine temperature — 12–15°C for active ripening; 4–8°C for storage
• Brine pH — should equilibrate to ~4.4–4.6; lower pH accelerates protein softening
• Calcium balance — calcium leaches from cheese to brine over time; periodic brine replacement or CaCl₂ addition controls this
• Microbial control — salt above 8% suppresses most spoilage; periodic brine filtration removes accumulated proteins and microbes

Common Defects and Troubleshooting

Frequently Asked Questions

What makes feta different from other cheeses?

Feta is distinctive in being matured in brine rather than aged in air or wax. Traditional feta is made from sheep milk (or sheep + goat) using a curd-cutting process with no cooking step, giving it high moisture (~55%) and a crumbly-creamy texture. EU PDO restricts the name "Feta" to cheese produced in specified Greek regions.

What's the difference between traditional feta and UF feta?

Traditional feta drains whey from cut curd before pressing — whey proteins (~50% of total protein) are lost. UF feta concentrates milk by ultrafiltration before coagulation, retaining all protein in the curd. UF gives 15–25% higher yield but slightly different texture and flavour. EU regulations distinguish the two for PDO purposes.

How long does feta need to mature?

EU PDO requires a minimum of 2 months brine maturation. Most commercial feta matures 2–6 months; premium aged feta can be 6–12 months. Longer maturation develops more pungent, sharp character.

Is feta always made from sheep milk?

Traditional Greek PDO Feta must be sheep milk or sheep + up to 30% goat milk. Outside the EU, "feta-style" white cheese is made from cow milk (most commercial production), sheep, goat or mixed milks. Within EU/UK, cow-milk products cannot be labelled "Feta".

What is the salt content of feta?

Final salt content is typically 2–4% in the cheese, equilibrated from the surrounding 8–12% brine. Some traditional and aged feta runs up to 6% salt.

Why is feta stored in brine?

Brine storage serves three functions: (1) preservation — high salt suppresses spoilage organisms; (2) flavour development — mild proteolysis during brine maturation develops characteristic taste; (3) texture maintenance — brine prevents cheese drying and surface rind formation.

Can you make feta from cow milk?

Yes, technically — many feta-style white cheeses are made from cow milk and the process is essentially the same. Yield is lower (cow milk has lower fat and protein than sheep milk), and the flavour is different (sheep-milk fat composition gives the distinctive feta character). In the EU/UK, cow-milk products must be labelled differently (e.g. "salad cheese", "white cheese").

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