Hard on the outside, soft on the inside: almost all cheese has a rind. Why? How does it form? Which are safe to eat and why is such great effort put into cultivating the cheese rind?
It is really quite simple: essentially, rind is nothing other than dried cheese. There is an order to this process, though. The first stage of rind formation occurs automatically. In cheese manufacturing, milk is thickened and whey is a by-product, with the resultant curd put in a form and pressed. This generates a boundary layer between cheese and its environment. “The first stage in the formation of the rind,” comments Klaus Kühefuss, Head of Cheese Development at Emmi. At this point, it is still soft. Things then really get going in the salt bath, when salt goes into the cheese and water – the whey – flows out. “This drying process above all takes place at the outside edges of the cheese,” says Klaus Kühefuss.
Desired and undesired spores
There are different types of rind. For example, Emmental or Sbrinz are dry-matured and treated only with salt water. In smear ripening, as done for Gruyère and Appenzeller, the cheese is regularly brushed with salt water containing bacteria. This bacteria is part of the ageing process, creating the mature flavour, as well as drying and deacidifying the cheese. As the bacteria need oxygen, they do not penetrate into the cheese but remain on the rind.
For bloomy rind cheeses such as Camembert, a mould is added, which is not just edible, but actually tastes good. Mould spores occur naturally and are everywhere in the air. They are green or black and often found in poorly ventilated cellars. These are of course not wanted on the cheese. Great effort is made to ensure they are held at bay while the rind forms. Salt wards off the mould, but also the bacteria and yeast in smear ripening. “It is a constant battle: the spores we want against the spores found in nature.” The rind acts as a barrier to the outside, similar to a banana peel. It preserves the cheese and is a natural packaging.
Cheese rinds can also be made artificially, with wax (Edam) or plastic. Dutch Gouda cheese is famous because the wheel is coated with a thin layer of plastic. “We don’t resort to such tricks here,” assures Klaus Kühefuss. In Switzerland, the cheese rind is all natural.
Eating rind: not for everyone
This begs the question of whether cheese rind is edible. More specifically: which taste good and which do not? Soft cheeses with noble mould such as Camembert and Brie are definitely safe to eat. “Smear-ripened rinds can also generally be eaten,” assures the cheese expert. However, they must be well washed. The rinds of washed Tilsiter and Luzerner Rahmkäse can be consumed without hesitation, but Gruyère and Appenzeller should be avoided as the smear is still on the rind.
With or without rind: when it comes to Raclette, it is almost a philosophical question, says Klaus Kühefuss. “Swiss Raclette cheese is washed and therefore edible – around half of all consumers eat the rind, the other half cut it off.” Cheese rind is a matter of taste and not for everyone. But there is no doubt that it is the protector of cheese. Without this hard shell, we would not have the soft core. And that would be a sad thing indeed.