Monterey Jack is an American semi-hard cheese made using cow's milk. It is commonly sold by itself, or mixed with Colby to make a marbled cheese known as Colby-Jack (or Co-Jack). Cheddar-Jack varieties are also available.
In its earliest form, Monterey Jack was made by the Mexican Franciscan friars of Monterey, California, during the 1800s. A Californian businessman by the name of David Jack first began to mass market the cheese. He produced a mild, white cheese, which came to be known at first as "Jack's Cheese", and eventually "Monterey Jack".
Most of the softer types generally found in American markets are aged for only one month, while another variety of Monterey Jack is aged for up to six months.
An aged version of this cheese, known as Dry jack, can be churned or grated and used much like Parmesan cheese. Dry Jack was originally developed during World War II by Peter Vella as the Italian styled cheeses became increasingly difficult to obtain due to the embargo imposed on Italy during the war.
Another version called Pepper jack mixes hot peppers with Monterey Jack for flavor. Pepper jack is often used as an alternative cheese in dishes such as quesadillas, but can be eaten with bread or crackers as a snack.
A common misspelling is 'Monterrey Jack', presumably in confusion with the Mexican city of Monterrey.
Because of its low content of tyramine, an organic compound thought to be associated with headaches, it is frequently recommended as one of the few cheeses that are safe to eat for migraine sufferers.