Cheese Making: It’s all about the curds!

When I’m out and about with my Cheese Making Kits, I often ask people if they’ve ever had a go at making cheese. There are a few standard responses: 1. they look at me as if I should be locked-up. 2. They are interested and intrigued and can’t wait to have a go:),  and 3. ‘only by mistake’ they say, and by the way, ‘it wasn’t very nice’ (no surprises there then!).

Cheese making is all about separating the curds from the whey which happens when milk is curdled using an enzyme or acid. We use Citric Acid,  a natural weak organic acid, often derived from fruit.  When it’s used in cheese making, it sours the milk and produces the chemical reaction which causes the milk proteins and fat molecules to come together and form the curd. This is the ingredient that those people who made cheese ‘by mistake’ missed, and so didn’t actually make cheese at all. Acidifying the milk not only helps the curds to form, but also to control the growth of undesirable bacteria which causes lumpy, gone-off milk to smell quite so bad!

Whey  is the yellowish water which we drain off after the curds have formed. The curds you’re left with can look and feel very different according to the recipe you are following, and the type of cheese you are making; this can be off-putting for the rookie cheese maker. The type and quality of the milk you use, the rate and temperature at which you heat the milk, and the addition of other ingredients all have a part to play in forming the curds.

The fat molecules in cow’s milk for example are much larger than those in goat’s (and sheep’s) milk.  This means the curds produced from goat’s milk are much smaller and softer, so much so they appear as small white specks which can be hard to see.

small goats cheese curds on stainless steel spoon

Curds forming from goat’s milk

When separated in a similar way, the curds from cow’s milk should appear as relatively large, light and fluffy lumps floating on the surface of the whey. You should avoid over-stirring the curds as you may damage their quality if they are not strong.

Ricotta curds forming within heating milk in a saucepan

The formation of ricotta curds from cow’s milk

The addition of Rennet will help to form a stronger curd, and is used in the making of mozzarella and hard cheeses. Rennet causes the curd to come together in a relatively firm mass which floats in the whey and looks and feels a bit like a giant blancmange!

“So, what should I do …as a last ditch attempt, to rescue things if it all looks to be going wrong?” was a question a wise lady asked me at the weekend.  Well, just dissolve a tiny bit of citric acid in water, add it to the pan, stir gently and you should find that is enough to really sort the curds from the whey :)