Historically, the name udun was used to avoid using a direct word for the buttocks, which was considered unclean because of its proximity to the excretory organs. Top round is a large, lean cut with a slightly dark color that discolors more quickly than other cuts. Its muscle fibers are relatively fine and uniform, but the meat’s tenderness can vary from one section to another, so you should be careful when slicing.
This cut is ideal for dishes where fat is undesirable. It is used in jangjorim (soy-braised beef), bulgogi, jumulleok (marinated beef), sanjeok (skewered meat), beef jerky, pancake dishes, and japchae (stir-fried glass noodles).
Sirloin is a single muscle cut with a bright, crimson-red color. The meat has a fine, soft grain and evenly distributed marbling. When grilled properly, you can fully enjoy its rich juices and the savory flavor of the marbling. However, since it lacks intramuscular fat, be careful not to overcook it, as it can become dry and tough. In other countries, sirloin is primarily used for steaks, but in Korea, it is also great for sanjeok or neobiani (marinated and grilled beef).