Cheddar cheese is a type of hard cheese that is made mostly from pasteurised cow's milk. In making Cheddar cheese, milk is heated to 30°C and inoculated with a lactic starter culture, after which rennet is added and the firm curd ground to marble-sized bits and heated to 38°C. After discarding the wey, the curd is sliced into slabs. The curd is pressed overnight and stands for 4 days in a cool atmosphere. It is generally matured between 9 and 24 months.

Considering the fact that raw milk is sometimes used, pathogens such as Listeria could be present in the cheese. Listeria contamination can cause miscarriages and stillbirths among pregnant women. In this regard, it is not advisable for pregnant women to eat soft cheeses such as Feta, Brie, and Camembert cheeses, blue-veined cheeses, and Mexican-style cheeses such as "queso blanco fresco."

However, Cheddar cheese is a hard cheese, and is less likely to be contaminated with Listeria; pregnant women may eat it.