Some like it hot – Temperature

Why do you need a good thermometer when making cheese and yoghurt? And why do you need the Finest Kind thermometer, specifically? Well, the Finest Kind thermometer floats in the milk or whey, constantly measuring its all-too-important temperature during the process of making any fermented food product.

Temperature is so important in making fermented food products because fermenting means you are utilising living organisms and enzymes to produce a delicious product such as cheese, yoghurt or bread.

Whereas fungi, which are plant-like, help to make bread, bacteria, which are more animal-like, are mostly used in the dairy industry (although some fungi are also used, for instance, to make camembert). Bacteria are very fussy creatures and can just park off if conditions aren’t just right for them to multiply and grow. Most lactic bacteria we use in milk, to convert the sugar lactose to lactic acid, are active at a temperature around 30°C. These are known as mesophilic bacteria. But some do like it hot.

Cheese is a way of storing milk and the drier the cheese the longer we can store it. Just think of Parmesan – it is stored for 18 months before we eat it. But to make a dry cheese we need to remove more moisture or whey from the curd and to do so we need to heat the curd. And this is where the thermophilic bacteria play their part. They like temperatures of 45°C and over.

Rennet, the enzyme that coagulates the milk in cheesemaking, also has a temperature preference, namely 30 – 43°C.  And the naturally occurring enzymes in milk such as the peroxidase, lipase, and phosphatases can be de-activated by high temperatures. Enzymes are molecules that activate a chemical reaction and are released again afterward. Most enzymes have a preferred temperature of between 25 and 50°C.

Vitamin A, B1, B2, C and D are found in whole milk. Of these, vitamin C is the most sensitive to heat and is the only one not found in cheese.

Proteins in milk are also affected by heating. The rate of coagulation of milk by rennet decreases with increasing pasteurization temperatures. This is because the casein protein in milk loses its calcium. Hence the need to add calcium chloride to pasteurized milk when making cheese.

Try making cheese with thermophilic bacteria – Asiago is one cheese which can be made. It originates from the town of Asiago just northwest of Venice and is good for grating on top of pasta, gratins, and soups. And best of all, it keeps well with minimal refrigeration, making it ideal when going on a camping trip.