We’ve put together a short guide that covers the basics of cheesemaking – for whatever cheese it is that you want to make.
Milk supply
A good milk supply is of course crucial. We’re lucky enough to be able to use our own milk as soon as our cows are milked each morning – you can’t get fresher than that!
It doesn’t matter whether you decide to use cows’, goats’, sheep’s or buffaloes’ milk. The key thing is to know that it is as fresh as it can be.
We gently pasteurise our milk by heating it and holding it at 63°C for 30 minutes. This approach means that the milk is guaranteed to be free of any nasties when we start cheesemaking – not that we’d expect there to be any! We’d recommend that novice cheesemakers use pasteurised milk too, particularly if you’re interested in making soft cheese. However, raw milk is an option if you are confident of the source.
Much of the milk you can find in a supermarket will have been flash pasteurised, which can damage it as far as cheesemaking is concerned (it is heated to 72°C for a minimum of 15 seconds – but frequently to a higher temperature and for more time). However, you should be able to buy good quality milk at your local farm shop, farmers’ market or even from our café.
Acidification
Fresh milk typically has a fairly neutral pH of around 6.6. Now, whether raw or pasteurised, the milk is now encouraged to acidify. This is the first stage in the process of turning milk from a liquid to a solid.
This is done by allowing (good) bacteria to consume the lactose in the milk and turn it into lactic acid. These bacteria occur naturally and these can sometimes be harnessed if you use raw milk (although it can be unpredictable). However, the majority of cheesemakers, ourselves included, will add a starter culture of bacteria to the milk to begin the process.
These cultures will vary depending on what type of cheese is being made and what types of flavour are being encouraged to develop. The temperature of the milk is also vital at this stage – if it is too hot the bacteria will be killed, too cold and the bacteria will not wake up. It depends on the type of culture but for most cheeses the milk temperature will be between 30°C and 35°C – although certain cultures, for example those used to make emmental, are heat loving and the milk will be correspondingly warmer.
Again, depending on what cheese is being made, ripening cultures may also be added to the milk at around this stage. There are many combinations of cultures to choose from but, for example, if you want to produce a white rind such as is found on a Brie, Camembert or our own Bath Soft Cheese, you would add Penicillium Camemberti while blue cheeses like our Bath Blue are typically ripened using Penicillium Roqueforti.
Coagulation
Once the acidification process is judged to be sufficiently underway, rennet is added to coagulate the milk into a solid. Rennet does this by causing the casein in the milk to precipitate (around 80% of the protein in cow’s milk is casein). Without getting too technical, the fat in the milk becomes trapped in a matrix of casein, leading to the formation of curd.
Traditionally, rennet is extracted from the fourth stomach of an unweaned calf (the enzyme in the rennet that acts on the casein helps the calf digest milk). However, today there are vegetarian options such as microbial rennet or plant extracts from cardoons or thistles. Opinions differ over whether the type of rennet affects the overall taste of the cheese but we use animal rennet in our Bath Soft Cheese, Kelston Park and Bath Blue but we use a microbial rennet for Wyfe of Bath – so it is entirely suitable for vegetarians.
It is also possible to make cheese without any rennet at all, using the lactic acid that has now developed in the cheese. Many goats’ milk cheeses are lactic cheeses – in part because goats’ milk responds less well to rennet than cows’ or sheep’s milk. Be that as it may, with the rennet added, the milk is left undisturbed while coagulation occurs.
Cutting the Curd
After an hour or so, the rennet will have transformed the milk into a solid, slightly gelatinous mass of curd. The whey (the liquid part of the milk) must now be released from the curd. This is done by cutting the curd evenly into smaller pieces.
The smaller the pieces of curd, the more whey is released and – by and large – the firmer and drier the eventual cheese will be. So our Bath Soft Cheese will be cut into larger pieces than Bath Blue .
Stirring at this stage will also help to release more whey. It takes all the cheesemaker’s skill and know-how to determine just how much to stir or cut the cheese to achieve the desired texture and consistency.
With some cheeses, such as Cheddar and Wyfe of Bath, it is desirable to increase the temperature of the curd to achieve a firmer set. The curd is scalded by draining off some of the whey and replacing it with hot water. Stacking the resulting curd in blocks on top of one another (a process known as ‘cheddaring’) also drives out more of the whey.
Salting and Shaping
The cheese has continued to acidify throughout the process. When it has reached a sufficient level of acidity, salt is added to halt further acidification. The salt also serves to add flavour, works as a preservative and helps to develop a rind on the cheese.
The salt can be added directly to the curds (Bath Blue), rubbed into the surface of the cheese once it has been moulded (Bath Soft Cheese) or the cheese can be soaked in a salt brine (Wyfe of Bath).
The curds are poured into moulds. These moulds will determine the size and shape of the finished cheese. Whey will continue to be expelled from the cheese through holes in the moulds. Some cheeses, such as Cheddar, are pressed to expel even more whey.
Affinage
The final stage of cheesemaking is to ripen the cheeses. Temperature and humidity must be carefully controlled to ensure the cheese matures at the right speed and with the right texture and flavour. Surface moulds are encouraged to develop (some cheeses have other cultures added at this stage) – or they may be washed in alcohol or brine.
It’s a delicate process requiring the full attention of the cheesemaker. Many cheeses require regular turning to ensure that they maintain a uniform shape. Our Bath Blue has to be pierced hundreds of times, allowing air in – without this, the blue moulds will fail to ripen evenly throughout the cheese. By contrast, Bath Soft Cheese develops a white furry mould which, with regular turning, is compressed into the distinctive white rind found on Brie and Camembert.
Soft cheeses ripen quickly – our Bath Soft Cheese is ready to eat within three weeks of being made. Hard cheeses mature more slowly with our extra mature Wyfe of Bath being allowed anywhere between one and two years. At this end of the scale, the resulting cheese develops an almost crystalline texture.