Temperature in Cheese: What’s it all about?
Temperature, and the ability to control it, is one of the most important parts of the cheese making process. It would be impossible to make cheese without understanding the effect temperature has on all stages of production; from the temperature the milk is stored at before it reaches us, to the temperature of the packing room before reaching you and all the stages in between!
At its simplest, cheesemaking is the transformation of milk to a solid product preserving the nutrients the milk contains. This process involves a lot of bacteria, both introduced by us as cheesemakers and naturally occurring.
In order for us to safely complete this process we use temperature to control exactly which bacteria are active at any given time during production. Most harmful bacteria do not like cold temperatures which is why you store most fresh food in the fridge as it prevents the rapid growth of spoilage organisms.
We do the same with milk and then the finished cheese: storing it at a low temperature prevents any of the bacteria we do not want from ruining the production. Harmful bacteria are also susceptible to very hot temperatures which is why we pasteurise our milk. Pasteurising is the process of heating milk to 72℃ for 15 seconds to kill any harmful bacteria that may be present.
During the make process there are a set of ‘rules’ that cheese tends to follow. The hotter the milk the faster the starter cultures divide and therefore the faster the acidification of the milk occurs.
The warmer the cut curds are kept, the more moisture they expel and therefore the harder the finished cheese will be. The opposite is true for things like lactic cheese.
The cooler the milk temperature the slower the starter cultures take effect and the slower the acidification of the milk. This means that the moisture in the curd is retained and the finished cheese is then much softer in texture. There are always exceptions to the rules however and some varieties of cheese, halloumi for example, will be treated with very hot temperatures and still retain a supple texture.
Temperature in the ageing rooms is critical. For our softer cheeses we need the initial ageing temperature to be quite high (18-20℃) in order to encourage the ripening bacteria to grow rapidly, thus forming a rind.
We call this ‘hastening’ and by encouraging the bacteria we do want, we help to alleviate the risk of the cheese growing undesirable moulds. For the remainder of the ageing process we reduce the temperature down (10-12℃) to prevent the cheeses from breaking down too quickly. We want the development of the rind to be stable so that the cheese is perfectly ripe when it is sent out to customers.
Hopefully by now you’re getting an idea of how vitally important the role of temperature is in cheese making. There is a lot of science involved in what we do as cheesemakers and this is just a brief overview of how we harness temperature to create cheese making magic.
Heather Taylor, Head Cheesemaker at Nettlebed Creamery