Cheesecloth is a specially designed fabric which was originally used in cheese production, hence the name. It has numerous other uses, primarily culinary. The fabric usually takes the form of a loosely woven cotton gauze, and is readily available from culinary supply stores as well as some sewing shops. In many cases, cheesecloth is also reusable, although it will break down eventually.
Superficially, cheesecloth looks like a mesh cloth, since the open weave leaves a number of small holes. The holes are close enough together to prevent solids from going through, but open enough to allow for plenty of drainage. For this reason, it is often used as a straining cloth. It is usually made from undyed cotton, so that it will be as neutral as possible.
In cheesemaking, cheesecloth is often used to wrap cheese, as the small holes in the cloth allow the cheese to breathe. Typically, multiple layers will be used to ensure that the cheese does not dry out. It is also used to press and drain curds, especially for farmer's cheese and similar soft cheeses. The curds are poured into the cheesecloth, allowing the whey to dry out, and the cheesemaker can squeeze the cloth to compact the curds before hanging the bundle to cure.
There are other culinary uses for cheesecloth. As a straining cloth, it can be used to clarify stocks and soups. A piece can be stretched over a clean pot to catch the broth, while the solids in the stock will be left behind. Cheesecloth is also used to strain and press yogurt to produce the thick, Greek style. Some cooks use it to make sachets of herbs and spices to be cooked with soups and stews. It may also be used to wrap meats while they cure.
Whatever the use, cheesecloth will not usually transfer flavor, since cotton is neutral. It will also not fall apart when wet and stretched, although over time, the edges may begin to fray. Cooks who wish to reuse cheesecloth can wash it in very hot water and soap, and hang it to dry. It may not always be reusable, especially if it has been simmered in a fatty soup in the form of a sachet, or used to make a very pungent cheese. Around the house, the fabric is also great for drying glass and covering fruits and vegetables to prevent insect infestations.