Almost all sushi bars in America, and most in Japan, serve imitation wasabi because the real product is extremely expensive. Imitation wasabi is usually made from horseradish, mustard, and green food coloring (sometimes spirulina), often as a powder to be mixed with water to make a paste. Since real wasabi loses its flavor if dried, powders containing real wasabi do not capture the genuine flavor. To distinguish between the true variety of wasabi and the imitation product, real wasabi is known in Japan as hon-wasabi (本山葵), meaning "original", or "true" wasabi.