Dhruv asks: Is cheese vegetarian or not? The cheese my mum buys has a green spot on it and says 'For vegetarians', but most others I've seen don't. Can you explain this, please?
Wynnie says: Cheese is made by coagulating milk using an enzyme called rennet to produce solids called curds and a liquid called whey. The curds are used to make a variety of cheeses.
Traditionally, animal rennet is used to curdle milk; it comes from the stomach of a newborn animal such as a calf, ewe or kid. The enzyme helps them to digest and absorb their mother's milk.
Vegetable rennet is often used instead these days. It can come from plants such as thistle, melon, artichoke and fig leaves. These plants contain enzymes capable of curdling milk.
Microbial rennets are becoming increasingly more popular; they are neither vegetable nor animal-based, but are made from micro-organisms derived from moulds such as mucor miehei, bacillus subtilis or bacillus prodigiosum. It's usually very difficult to distinguish any difference in taste between cheeses made with different rennets.
Some cheeses are expressly labelled as suitable as vegetarian, or some have a 'V' or a green dot on the label. It's best to read the ingredients list, if you're unsure. Most companies list vegetable rennet or vegetable enzymes expressly. If the ingredients contain rennet, rennase, chymosin or pepsin, the cheese was curdled with animal rennet.