From milk to cheese: the processes of cheesemaking

Cheese is one of those products where the dairy technician's expertise really comes into play. The process from milk to cheese is about controlling chemical and microbiological reactions with precision — temperature, time, acidity and the right cultures must work together for the result to be the cheese the recipe describes.

§Two basic routes to cheese

According to Landbrug & Fødevarer, cheese can be made in two fundamentally different ways: as fermentation cheese, where milk coagulates with help from lactic acid bacteria, or as rennet cheese, where an enzyme causes the milk to separate into cheese solids and whey. A third type, whey cheese, is made from the by-product of the other two methods.

§Løbens rolle i processen

Løbe er det enzym, der omdanner mælken ved at få proteinet kasein til at koagulere, så mælken skiller i den faste ostemasse og den flydende valle. Når ostemassen er dannet, skæres den i mindre stykker. Jo mindre stykkerne skæres, jo mere valle kan sive fra, og jo tørrere og fastere bliver den færdige ost — det er en af de knapper, du som mejerist skruer på for at ramme den rette konsistens.

• 01Standardization of milk fat content
• 02Pasteurisation of the milk
• 03Adding fermentation culture and whey
• 04Coagulation and cutting of the cheese mass
• 05Heating ("reheating") and stirring to press whey out
• 06Separation of whey and forming/pressing of the cheese
• 07Salting, either in salt brine or by dry salting
• 08Maturing under controlled temperature and humidity

§The importance of cultures for taste

The flavor differences between different cheeses largely arise from the cultures and enzymes that are added. Work is done with, among other things, lipase enzyme, white mold, blue mold, smear cultures and yeast, each of which develops different flavor nuances during aging. Temperature, humidity and especially time have a major influence on how the flavor develops — a white-mold cheese and a blue-mold cheese can start as the same cheese mass and end up as two completely different products.

§Whey cheese — when the byproduct becomes a new product

With ordinary cheesemaking, approximately 10–20% of the milk's proteins do not end up in the cheese mass but remain in the whey. These proteins can be utilized by heating the whey to 85 °C or more, whereupon the whey proteins precipitate and can be collected for whey cheese such as curd, cnapost, fresh cheese and smoked cheese. It is a way to fully utilize the raw material — something the dairy industry is placing increasing emphasis on as focus on resource utilization grows.

§Dairy worker's tasks during the process

Throughout the entire cheesemaking process it is the cheesemaker's task to continuously monitor temperature pH and timing and adjust according to how the cheese mass reacts—because no batch of milk is quite the same. Documentation of each step is at the same time part of the dairy's quality control so the process can be traced back if anything should later prove to be wrong.

“Osten kan groft sagt laves på tre måder: som syrningsost, som løbeost, eller som valleost af biproduktet fra de to andre.”

— Agriculture & Food, lf.dk