Are you baffled, or even annoyed, by the liquid pooling on top of your yogurt?
Some people suggest stirring it back into the yogurt. Others suggest pouring it down the drain. I suggest pouring it into a container and saving it — but only (and this is important) if you’ve got plain yogurt, without added ingredients, such as fruit, vanilla, coffee, pectin or sugar.
The liquid that you pour off will become a key ingredient for a food that you may have bought at the supermarket, but which you never dreamed you could make yourself at home — a soft cheese similar to Italian ricotta (traditionally used in Italian cooking in lasagna, stuffed pasta such as ravioli, and also pastries).
The liquid on your yogurt is whey, from the Old English hwæg. When whey is a byproduct of cheese-making, it’s known as sweet whey; when it results from the production of yogurt, it’s known as acid or sour whey.
Italian ricotta is made from sweet whey, which forms fine curds when brought almost to the boiling point.
In Tuscany, the two most common kinds of ricotta derive from cheeses made with the milk of sheep or cows. Cows can provide milk year round, but sheep only during the 80 to 100 days after lambing, which takes place in winter or early spring.
Sheep’s ricotta is rich (about 24 per cent fat) and has a slightly nutty flavour.
The ricotta that you can make at home using the acid whey formed by your plain (and preferably organic) yogurt results from a slightly different process, although the end product is as delicious as any ricotta I ever ate when I lived in Florence.
If you search on the web you’ll find various recipes for making ricotta, but none are as simple as the one I use.
The ingredients are whey from plain, preferably organic, yogurt, best if at least two per cent, and (organic) milk, at least two per cent. The proportions are one part whey to four parts milk. I use 250 ml whey to one litre milk, which makes about one cup of ricotta.
Pour whey and milk into a saucepan and stir well to mix the two. Turn the heat to low and use a candy thermometer to check the temperature. Do not stir the mixture again.
When the temperature is about 150 degrees Fahrenheit, you’ll see curds starting to form. Heat until the temperature reaches 180-190 degrees Fahrenheit. Take the saucepan off the stove and let it sit for 10 to 15 minutes.
In the meantime place a sieve, lined with cheese cloth, over a small bowl. Use a mesh ladle to scoop out the curds and place them in the sieve. Let the liquid drain off until the ricotta is as moist or dry as you like it.
Slip the finished ricotta into a container and close with a lid. It’ll keep in the fridge for about one week — unless, like me, you eat it immediately.
Sabine Eiche is a writer and art historian. SabineDellarovere.com
