Sticky, short-grained rice is the staple food in Japan. Uncooked rice is called kome. The cultivation of rice in paddy fields traditionally required great cooperation between villagers and this is said to have been central to the evolution of Japanese culture. Their are several thousand varieties grown in Japan, with Koshihikari and Akita Komachi being among the most popular. Rice is also used to make mochi (rice cakes), senbei (rice crackers) and sake (rice wine). Rice can also be cooked with red beans (sekihan), seafood and vegetables (Takikomi gohan) or as a kind of watery porridge seasoned with salt (kayu) which is very popular as a cold remedy. Onigiri are rice balls with seafood or vegetables in the middle, usually wrapped in a piece of dried seaweed (nori). They are traditionally part of a packed lunch or picnic. Individually wrapped onigiri, usually a trianular shape, make a good snack and are available at convenience stores.