Yuzu is a citrus fruit, somewhat similar to lemon though often described as having more aroma and flavor.  The fruit can grow up to 16 cm in diameter and has yellowish skin that is relatively thick with bumpy sections that adhere easily to the juice within. The yuzu's flavor is usually classified into four categories- sweet, bitter, sour, and salty- each of which corresponds roughly to one of these four adjectives added together with some very subtle differences.