유자 is a citrus fruit native to East Asia, particularly popular in Korea, Japan, and China. It has a unique flavor that is a mix of lemon and grapefruit, with a fragrant aroma. The fruit is typically yellow or green and is often used in cooking, beverages, and traditional remedies. In Korean cuisine, 유자 is commonly made into a sweet and tangy preserve called 유자청 (yujacha), which is enjoyed as a tea or used as a flavoring in various dishes. The fruit is also rich in vitamin C and antioxidants, making it a healthy addition to the diet.