Monterey Jack (sometimes shortened simply to Jack cheese) is an American semihard cheese, customarily of pale yellow, 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 19th century. Californian businessman David Jack sold the cheese commercially. He produced a mild, white cheese, which came to be known as "Jack's Cheese", and eventually "Monterey Jack".
A common misspelling is "Monterrey" Jack, presumably in confusion with the Mexican city of Monterrey.
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 grated and used much like Parmesan cheese. Dry Jack was originally created by accident in 1915 when a San Francisco cheese wholesaler stored and forgot a number of wheels of fresh Jack cheese.
When shipments of hard cheese from Europe were subsequently interrupted as World War I intensified, he rediscovered the stored Jack, which had become a well-aged hard cheese his customers found to be a good substitute for classic, aged hard cheeses such as Parmesan.
Another version called pepper jack mixes hot peppers with Monterey Jack. 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. Other versions are flavored with garlic or pesto, though they are less common than pepper jack.
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 is safe to eat for migraine sufferers.