目录导航
- 1. The Undisputed Favorite: Why is 横膈膜 Loved by So Many 烧肉 Enthusiasts?
- 2. The Hidden Truth: Why 横膈膜 is Classified as 牛内脏 (牛内脏) Rather Than Red Meat
- 3. Does Freezing Destroy Umami? The Science of Ice Crystals and “Drip Loss”
- 4. Why Does Frozen Meat Taste Dry or Metallic? Oxidation and Amino Acid Loss
- 5. 黑5’s Commitment to Fresh (Never-Frozen) Beef: Intact Cells and Incredible Juiciness
- 6. Only 2kg Per Cow: The Ultra-Rarity and Rich Sweetness of Domestic A5 和牛 横膈膜
- 7. 2cm Thick & No Score Cuts: Why Fresh 和牛 横膈膜 Needs No Score Cuts
- 8. 纪州备长炭 & 10-15 Second Flipping: The Pro Technique for Sealing in Juices
- 9. Comparison: 3 Key Differences Between Standard Frozen 横膈膜 and 黑5 Fresh 和牛 横膈膜
- 10. Conclusion: Experience Authentic Fresh 横膈膜 at 黑5 Tonight

Hello everyone, this is Sondo from 黑5.
When you visit a 烧肉 restaurant, what is the number one cut you look forward to ordering alongside 牛五花 and 牛里脊? For many meat lovers, the immediate answer is “横膈膜” (横膈膜)—celebrated for its tender texture, rich savory flavor, and juicy finish. It offers a satisfying bite without being as heavy as 牛五花, making it a timeless favorite across all generations.
However, did you know that most of the 横膈膜 served at standard 烧肉 restaurants is actually “frozen 横膈膜” that was frozen solid before being thawed in the kitchen? Between standard frozen 横膈膜 and fresh (never-frozen) 横膈膜, which is kept chilled from sourcing to your table, there is a fundamental difference in texture, aroma, and juiciness. Why does freezing meat degrade its flavor? The answer lies in microscopic cellular structures and fluid dynamics. Today, I would like to explore the appeal of 横膈膜 and share the secrets behind 黑5’s founding obsession with fresh 和牛 and fresh 横膈膜.
1. The Undisputed Favorite: Why is 横膈膜 Loved by So Many 烧肉 Enthusiasts?

First, let us examine why 横膈膜 captivates so many diners.
The main attraction of 横膈膜 is its perfect balance between rich umami and a light, clean finish. Highly marbled 牛五花 delivers an incredible first impression, but eating multiple pieces can feel heavy on the stomach. On the other hand, lean cuts like 牛里脊 are easy to eat, but you may sometimes want a juicier, more substantial flavor. 横膈膜 combines the best qualities of both.
Within its tender muscle fibers, fine marbling is evenly distributed. When seared over 炭火, the surface crisps up while rich juices burst forth with every bite. Yet because its fat profile is light, it never leaves your stomach feeling heavy. This golden balance—offering the satisfaction of 牛五花 with the lightness of 牛里脊—is why 横膈膜 remains a king among 烧肉 cuts.
2. The Hidden Truth: Why 横膈膜 is Classified as 牛内脏 (牛内脏) Rather Than Red Meat

While 横膈膜 looks and tastes like a premium red steak, it holds an interesting classification in the meat industry. According to agricultural and culinary standards in Japan, 横膈膜 is classified not as primary red muscle meat, but as 牛内脏 (牛内脏).
Specifically, 横膈膜 is the cow’s diaphragm muscle. The thinner back portion of the diaphragm is called “横膈膜,” while the slightly thicker abdominal portion is called “Sagari.” In humans, this is the respiratory muscle that moves when you hiccup. Why does an internal diaphragm muscle taste so much like rich red meat?
Because the diaphragm is a respiratory muscle (red muscle) that works continuously 24/7 as the cow breathes, it consumes large amounts of oxygen, making it rich in myoglobin protein and iron, giving it a deep red color. Furthermore, unlike leg muscles that support heavy body weight and grow tough, the diaphragm remains flexible and soft. As a result, when cooked, it does not toughen up, offering the deep richness of 牛内脏 combined with the tenderness of red meat.
3. Does Freezing Destroy Umami? The Science of Ice Crystals and “Drip Loss”

Now let us address the core question. Despite 横膈膜’s qualities, most 横膈膜 at standard restaurants is frozen for long-distance ocean transport or easier inventory management. However, freezing meat even once alters its fundamental quality. There is a clear scientific reason for this.
Meat is composed of roughly 60% to 70% water. When meat is frozen, the water inside its cells freezes into ice crystals. In standard commercial freezing, where temperature drops slowly, these ice crystals grow large and sharp, acting like microscopic needles that puncture and destroy the cell walls from within.
When this frozen meat is thawed in the kitchen, the fluid held inside the cells leaks out through the damaged cell walls. This liquid is known as “drip loss.” While it might look like clear fluid or blood, this drip is packed with the meat’s primary umami components (glutamic acid and inosinic acid), amino acids, vitamins, and minerals. Losing drip means draining away the beef’s natural flavor and nutritional value.
4. Why Does Frozen Meat Taste Dry or Metallic? Oxidation and Amino Acid Loss

Thawed meat that has lost its cellular fluid exhibits two major flaws when placed on the grill.
First, because the cell walls are damaged and can no longer hold moisture or fat, heat causes the remaining moisture to evaporate immediately. As a result, the cooked beef becomes dry, chewy, and fibrous. No matter how rich the marinade is, it cannot restore the natural juiciness of intact meat cells.
Second, there is the issue of odor. As the leaked fluid (containing blood and moisture) contacts the air, the fats and hemoglobin oxidize rapidly. This oxidation produces a stale, metallic, or bloody odor. Because diaphragm and 牛舌 tissues have active blood circulation, they are especially vulnerable to oxidation odor when frozen and thawed. If you have ever disliked 横膈膜 due to a metallic aftertaste, you were likely tasting oxidized drip loss from frozen meat rather than true 横膈膜.
5. 黑5’s Commitment to Fresh (Never-Frozen) Beef: Intact Cells and Incredible Juiciness

At 黑5, our founding principle is our uncompromising commitment to fresh, never-frozen beef. From sourcing to preparation to your table, our beef is never placed in a freezer.
Our 和牛 横膈膜 and 和牛 牛舌 are shipped fresh under strict chilled temperature control (0°C to 2°C). Because it is never frozen, the cell walls remain 100% intact. The natural moisture, amino acids, and low-melting-point oleic fats stay sealed inside the cells.
When fresh 横膈膜 is placed on our 炭火 grill, no drip leaks out. As far-infrared heat warms the meat, the intact cell walls lock the juices inside, causing the meat to plump up on the grate. The moment you bite into fresh 和牛 横膈膜, smooth tenderness yields to a burst of rich juice and sweet 和牛 fat. Free of dryness or metallic odor, this clean, rich flavor is only possible with fresh, never-frozen 和牛.
6. Only 2kg Per Cow: The Ultra-Rarity and Rich Sweetness of Domestic A5 和牛 横膈膜

黑5’s 横膈膜 also stands out due to its bloodline and quality. Over 90% of 横膈膜 served in Japan is imported beef from the US or Australia. While imported 横膈膜 has a bold red-meat flavor, it cannot match 和牛 in fat sweetness or tenderness.
We source exclusively domestic A5-rank Kuroge 和牛 fresh 横膈膜. A single 和牛 cow (weighing 700kg to 800kg) yields only 4kg to 5kg of 横膈膜. After trimming away excess fat and connective tissue, only about 2kg of usable 烧肉 meat remains per cow, making it an extremely rare delicacy.
Domestic A5 和牛 横膈膜 features dark red muscle fibers covered in a layer of pure white 和牛 fat. High in oleic acid, this fat has a melting point below human body temperature, rendering it smooth and easy to digest. Grilling it over 炭火 releases a sweet, aromatic “和牛 fragrance” (和牛-ko), pairing rich red meat flavor with clean fat sweetness.
7. 2cm Thick & No Score Cuts: Why Fresh 和牛 横膈膜 Needs No Score Cuts

Guests ordering fresh 和牛 横膈膜 at 黑5 often notice two features: our generous 2cm thick cut and the absence of score cuts (隠し包丁なし) on the meat surface.
Standard restaurants often slice 横膈膜 thin or score the surface with fine cuts to make tough, frozen-thawed meat easier to chew. However, scoring the surface ruptures the cells, allowing juices to drain onto the grill during cooking.
黑5’s fresh A5 和牛 横膈膜 requires no score cuts. Because it is never frozen, its natural muscle fibers remain tender and supple, allowing your teeth to slice effortlessly through a 2cm thick cut. By leaving the surface smooth and uncut, we sear the exterior evenly over 炭火, sealing 100% of the juices inside the thick block of beef.
8. 纪州备长炭 & 10-15 Second Flipping: The Pro Technique for Sealing in Juices

To cook this 2cm thick fresh 和牛 横膈膜 perfectly, 黑5 staff grills every piece at your table using our “full-attend style.” Grilling a 2cm thick cut requires precise heat control to avoid burning the exterior while ensuring the center is properly heated.
We practice a method of frequent flipping every 10 to 15 seconds over 纪州备长炭 炭火.
By turning the meat every 10 to 15 seconds over high far-infrared heat, we protect the surface while encouraging internal thermal convection. This gentle, frequent turning acts like a covered roast on an open grill, elevating the core temperature without contracting the muscle fibers.
The result is a caramelized, smoky exterior wrapping a juicy, medium-rare center. When served to your plate, every bite delivers a contrast of crisp exterior, tender texture, and bursting juice.
Serving Suggestions:
Enjoy thick slices of fresh 横膈膜 simply with salt and pepper to taste the pure sweetness of fresh 和牛 fat. For standard slices, we recommend our special tare mixed with a touch of miso. The deep savory notes of miso and soy tare enhance the rich beef flavor—especially when enjoyed over a bowl of hot white rice.
9. Comparison: 3 Key Differences Between Standard Frozen 横膈膜 and 黑5 Fresh 和牛 横膈膜
3 Differences Between Standard Frozen 横膈膜 and 黑5 Fresh 横膈膜
1. Storage Condition and Cell Integrity:
- Standard 横膈膜: Frozen and thawed before serving. Large ice crystals rupture cell walls, causing heavy drip loss, dryness, and metallic odors.
- 黑5 横膈膜: Kept chilled and fresh from sourcing to table. Cell walls remain 100% intact, locking in natural juices, amino acids, and aroma.
2. Bloodline, Thickness, and Scoring:
- Standard 横膈膜: Uses imported beef sliced thin or scored with cuts to soften tough, thawed fibers (allowing juices to leak during grilling).
- 黑5 横膈膜: Uses rare domestic A5 和牛 (2kg yield per cow), served in 2cm thick cuts without score cuts to preserve internal moisture.
3. Grilling Method and Pairings:
- Standard 横膈膜: Left to guests to grill, often leading to charred exteriors or dry centers.
- 黑5 横膈膜: Grilled by staff using 纪州备长炭 炭火 and 10-15 second flips for a medium-rare finish, paired with salt or signature miso-tare over rice.
10. Conclusion: Experience Authentic Fresh 横膈膜 at 黑5 Tonight
横膈膜 is far more than a simple everyday 烧肉 cut. When sourced fresh and never frozen, A5 和牛 横膈膜 offers an extraordinary combination of tender texture, rich juiciness, and sweet aroma that redefines what 横膈膜 can be.
At 黑5, we maintain our commitment to fresh beef, hand trimming, and table-side 纪州备长炭 grilling so our guests can experience beef at its absolute best.
We invite you to visit 黑5 Honten, Higashiguchi, or 歌舞伎町店 tonight. Let our trained staff grill our signature fresh 和牛 横膈膜 for you at your table for an unforgettable dining experience.

- 炭火 烧肉 黑5 Honten
1F Nishi-池袋 Bldg, 2-46-3 Nishi-池袋, Toshima-ku, Tokyo / 5 min walk from JR 池袋 Station - 炭火 烧肉 黑5 Higashiguchi
1F Tsukiji Bldg, 1-42-16 Higashi-池袋, Toshima-ku, Tokyo / 3 min walk from JR 池袋 Station East Exit - 炭火 烧肉 黑5 歌舞伎町店
1F Sankyo Akagawa Bldg, 2-21-4 歌舞伎町店, Shinjuku-ku, Tokyo

