Gruyère is formed in large wheels of 70 to 80 pounds (32 to 36 kg) with a brownish, wrinkled natural rind. The interior is pale gold with pea-sized, or slightly larger, holes and a rich, nutty flavour; it is similar to Emmentaler (q.v.) and other Swiss-type cheeses but firmer in texture, with fewer holes and a more assertive flavour. Most Gruyère is aged for three to six months, although some may be allowed to ripen for a year or more. It keeps well for many weeks if securely wrapped and refrigerated.