Some people talk about raw milk, while others talk about unpasteurised milk. Raw and unpasteurised are not necessarily the same, so what makes them two different things? Well, any heat treatment of the milk above 40 degrees, but which is not pasteurisation. Pasteurisation is about heating the milk to 63 degrees centigrade for 30 minutes or to 73 degrees for 15 seconds. Some choose however to treat the milk in a process called thermisation. This means that you heat the milk to 63 degrees centigrade for 15 seconds. It is the same temperature as in so-called low pasteurisation, but for a much shorter time and is therefore not pasteurisation. Alternatively, the milk can be thermalised by heating it to 56 degrees for 30 minutes.
Thermalisation of the milk does not occur often, but is far from rare. I have received somewhat varying explanations as to why the milk is thermalised. Some say that it is to stabilise the milk where they do not make cheese every day, or where the milk has to be transported over a long distance. Others say that after all, thermalisation kills some dangerous bacteria without harming the good ones.
The reason I use the term raw milk is that unpasteurised is too unvarnished in my world. If the milk is thermalised before curdling, the cheese will still be curd from unpasteurised milk, but not from raw milk. I understand that it can be confusing, and some will argue that it is s on my part. However, many people perceive unpasteurised and raw milk as the same thing, so this is my little crusade.
Some who make cheeses, especially in Great Britain, define the cheeses as unpasteurised, which they actually are, but made from thermalised milk and not from raw milk. It will give a wrong perception of how the milk has been treated when this is not specified. Then I wonder if this is done on purpose since most people think that unpasteurised milk is the same as raw milk. If a French cheese is made with thermalised milk, it will be declared. I don’t think the French even have a term called unpasteurised.
A rule of thumb in cheese making says that if cheese is made from raw milk, they must be extra careful with hygiene up to the cheese vat, but if the milk is pasteurised, they must be similarly careful after the cheese vat. Now, good hygiene control in the barn, milking parlour, the cheese factory and in the ripening room is of utmost importance of course, but cheese made from raw milk is considered more robust against external influences. There are more good knights than villains among the bacteria in general, but the latter get more mention. It’s always like this, the bad kids get the most attention.