Deungsim (Korean Sirloin Primal)

Longissimus dorsi and adjacent muscles along the dorsal spine, from rib 5–6 through the lumbar region. Includes the rib section (analogous to Western ribeye/rib cap) and the loin section (analogous to striploin/NY strip). Korean butchers often keep this as a unified block rather than separating at the rib-loin break.

1. 1For gui steaks (1–1.5 cm thick): bring to room temperature 30 minutes before grilling; cook on a very hot charcoal grill 2–3 minutes per side for medium-rare.
2. 2Fat cap management: Korean diners debate 'fat on' vs. 'fat trimmed.' Leaving the fat cap on creates self-basting; trimming it and cooking the fat strip separately as a grill lubricant is equally traditional.
3. 3Score the external fat cap at 1 cm intervals before grilling to prevent the steak from curling as the fat contracts.
4. 4For bulgogi slices: semi-freeze the block, slice 2–3 mm across the grain, marinate in soy-pear-sesame mixture 30–60 minutes, grill on high heat.
5. 5Hanwoo deungsim (1++ grade) needs no marinade—salt and sesame oil only, like yakiniku preparation.
6. 6Rest steaks 3–5 minutes before slicing; serve with perilla leaves, doenjang, and sliced garlic.

• The external fat cap is typically trimmed to 5–8 mm for gui; Korean butchers leave more than Western steakhouses to protect the meat over high direct heat.
• Score the fat cap shallowly every 1 cm to allow rendering without causing the steak to buckle.
• For gui presentation: cut across the grain into 1–1.5 cm slabs; for bulgogi, semi-freeze and slice 2–3 mm.
• Trim silver skin from the cap muscle (spinalis) end if present—it does not render and will tighten during cooking.

• Striploin (NY strip)

  The closest Western equivalent to the loin-end of deungsim; slightly less marbled than the rib-end.

• Ribeye

  Equivalent to the rib-end of deungsim; both share the spinalis cap muscle and intramuscular fat distribution.

• Wagyu striploin

  Best substitute for hanwoo deungsim when Korean cattle are unavailable; similar BMS marbling level.

• Ribeye

  Western equivalent of the rib-end deungsim; identical muscle (longissimus dorsi + spinalis) with different butchery conventions.

• Striploin (NY Strip)

  Western equivalent of the loin-end deungsim.

• Bulgogi Slice

  The 2–3 mm sliced retail product most often derived from deungsim.

• Chaekeut (Tenderloin Sirloin)

  Adjacent primal—leaner, more tender, less marbled; sometimes confused with deungsim by non-specialists.

1. 1.Korean Beef — National Agricultural Products Quality Management Service (NAQS), Korea
2. 2.The Korean Cookbook — Judith Ridner & Taekyung Chung, Phaidon
3. 3.Meat Buyer's Guide — NAMP / North American Meat Institute (for cross-reference to Western primal mapping)

Confidence: high