Blue cheese is a type of cheese that is characterized by its distinct blue or green veins, which are created by the mold Penicillium. This mold is introduced during the cheese-making process, giving blue cheese its unique flavor and aroma. The texture can range from creamy to crumbly, and it is often aged for several months to develop its strong taste. Common varieties of blue cheese include Roquefort, Gorgonzola, and Stilton. These cheeses are often used in salads, dressings, and sauces, or enjoyed on their own with crackers or fruit. Blue cheese pairs well with sweet flavors, making it a popular choice for gourmet dishes.