One of the main things that defines a good goats' cheese is its rind, and getting them to come out exactly how we want them to be is mixture of art, science, experience...and sometimes luck.
If you leave a fresh cheese to ripen at 10C on its own (which is the traditional French way), you get a huge variety of microflora growing on the rind. You get some cream and white moulds, but also a whole array of blue, green and grey mould. They add flavour and complexity - check out this picture of what grows on a Crottin as it ages:
These blue surface moulds on the rind of a goats' cheese are perfectly safe to eat, and some presence on the rind adds flavour. However people are not always used to seeing them, and can find them a bit scary!
To help control what grows on the rind, cheesemakers often add yeasts and moulds to their cheeses. Most of these are naturally occurring in milk anyway, so adding a little bit extra of them just helps tip the balance in favour of the ones you want growing on the rind, making it less likely other things will grow. The two most common things to add to a soft cheese are geotricum, which is a yeast, and penicillium candidum, a mould (but definitely not the same as penicillin the medicine!). The white rind you are used to seeing on a brie or camembert is formed from these two being added to the milk. Geotricum makes the rind take on a cream colour and gives it a wrinkly appearance, while penicillium candidum creates the fluffier, velvety white outer coating.
Our preference is for a rind that is formed of the yeast geotricum as it gives the subtlest flavour and allows the milk itself to be best expressed in the cheese. The cheeses start off with a plain white surface:
Then after a few days of being kept in warm, moist conditions, the wrinkly cream covered geotricum starts to grow:
If we add penicillium candidum, this starts to appear as small white dots a few days later in slightly drier conditions:
Over time, these grow into a thicker coating that covers the cheese. However as the penicillium candidum grows more thickly, the cheese starts to take on the appearance of the rind of a brie - velvety and covered in white. Then the cheeses can start to take on a brie/ camembert flavour which overwhelms the more subtle and natural goats' cheese flavours. You also risk getting a bitter flavour under the rind, which we don't want.
So although the white velvety coat can look attractive, we don't add it to our cheese and instead favour a natural rind.
Traditional French goats cheeses - which is the style our cheese is made in - usually don't have any penicillium candidum added to the rinds, so some amounts of blue/ grey mould typically start to appear after about a week. This is fine and they are safe to eat but are what sometimes cause people concern if they are not used to seeing it on their cheese. This is the kind of mould that grows - you might think it looks different or 'off', but it is actually just at a point of being lovely, tasty and perfectly safe and edible!
Exactly what grows is affected by the original composition of the milk (which changes every day), the season, the weather and humidity during the making and ripening of the cheese, the precise temperature it is kept at, and exactly for how long, how long the cheeses are drained and dried before ripening, and then just a little bit of luck! We make detailed notes for every cheese we make on exactly what the conditions are like and exactly what we do each time, so we can work out what we think works best. However it is an ongoing process - a mixture of art, science, and personal preference. This are some of my favourites at one week, two weeks and three weeks old:
As you can see in the background of last picture, the inside of the cheese remains completely white. So then it's up to you whether to eat the rind or cut it off! Either way it should taste great.
If you've got any views on the rinds on our cheeses, do get in touch and let us know.