Cheese-making is a fascinating combination of art and science. Every step in the process, from choosing the right milk to implementing suitable ripening methods, contributes to the creation of distinct flavours, textures, and aromas that define different types of cheese. The art of making certain cheeses has been passed down from generation to generation. Each new generation adding its improvements. This entry serves as a comprehensive guide and sheds light on all the different steps a cheese maker goes through to create this amazing product called cheese.
Milk Selection and Treatment
The quality and source of milk are fundamental to the cheese-making process, profoundly influencing the flavour, texture, and nutritional profile of the resulting cheese. Milk from different animals such as cows, goats, or sheep, each imparts unique characteristics due to variations in fat content, protein structure, and the presence of specific fatty acids.
The process of pasteurisation, involving heating the milk to 63°C for 30 min to eliminate pathogenic microorganisms, is a critical step in ensuring the safety and consistency of the final product. This treatment also affects the milk’s microbiological and enzymatic profile; therefore, some cheeses are done without this step to preserve the final flavour and texture. At this stage, calcium chloride may be introduced to improve curd formation later in the process. It can also increase the yield by 2-3%. Particularly useful is calcium chloride when making goat cheese since goat milk has a naturally soft curd, which helps to make a firmer curd.
Acidification
Acidification is a pivotal step in cheese making, where the transformation of milk into cheese begins through bacterial activity. This process involves the addition of specific starter cultures, typically lactic acid bacteria such as Lactococcus, Lactobacillus, or Streptococcus. These bacteria ferment lactose, the sugar in milk, producing lactic acid as a byproduct. The resulting decrease in pH causes changes in the milk proteins, particularly casein, leading to coagulation (destabilisation of the milk micelles, causing them to merge and form a solid mass).
Acidification significantly influences the texture and flavour of the cheese; a lower pH leads to a firmer texture due to tighter protein networks. Additionally, the type and activity of the bacteria used can impart distinct flavour profiles to the cheese, as different strains produce varying amounts and types of metabolites during fermentation.
Coagulation
The coagulation process is crucial not only for determining the basic structure of the cheese but also for influencing its final texture. The firmness, elasticity, and moisture of the curds can be manipulated through subsequent cheese-making steps, allowing for the production of a wide variety of cheese types with distinct characteristics. This process can occur through different methods, including rennet coagulation or acid coagulation.
Rennet Coagulation: Rennet is a complex of enzymes typically derived from the stomachs of young, nursing ruminant animals as part of livestock butchering and contains the enzyme chymosin. This enzyme acts on the milk proteins, causing them to form a gel or curd.
Acid Coagulation: Acid coagulation, also known as lactic coagulation, involves using acid to coagulate milk. This can be achieved by directly adding acid or using starter cultures to lower the pH by converting lactose to lactic acid
Both coagulation methods lead to the destabilisation of the milk micelles, causing them to merge and form a solid mass. This process is fundamental in cheese making, as it is the initial step in transforming liquid milk into a solid curd, which is a key component in producing various cheese varieties
Curd Processing
After the milk has coagulated, the curds undergo cutting, cooking, and stirring; each step is crucial in defining the cheese’s final texture and moisture content. Cutting the curd increases its surface area, facilitating whey expulsion. The size of the curd pieces is key: smaller curds release more whey, resulting in a firmer cheese, while larger curds retain more moisture, leading to a softer cheese. They are then cooked to expel more whey, which enhances the firmness of the cheese. The temperature and duration of cooking are carefully controlled to achieve the desired consistency, as higher temperatures lead to tighter curd formation and a harder cheese texture. The heating temperature of cheese curds typically ranges from 35°C to 38°C. This temperature is achieved over 30 to 60 minutes, with a recommended increase of about 1°C degree every 5 minutes. If the curds are heated too fast, they form a rind-type surface, preventing the whey from being expelled. To prevent matting and even cooking, curds are stirred while they are heated.
