If the broth is the soul of Phở and the spices are its voice, the meats are its personality. A great bowl of phở is never a monolith of a single protein; it is a curated textural canvas. When ordering or preparing phở, diners can choose from a fascinating array of cuts that range from buttery and melt-in-your-mouth to crisp, gelatinous, and toothsome.
Understanding how each cut responds to heat and knife work is essential for mastering the art of phở assembly.
The Meat Matrix: cuts and their characteristics
1. Rare Eye of Round / Tenderloin (“Tái”)
- The Cut: Lean, tender beef cuts (typically eye of round or tenderloin) sliced paper-thin.
- The Science & Culinary Role: Because these cuts are exceptionally lean with almost zero connective tissue, long simmering would turn them dry and chalky. Instead, they are served raw directly into the bowl. When the boiling broth is ladled over them at the table, the residual heat gently denatures the muscle proteins (myoglobin and actin), cooking them to a tender, delicate medium-rare just as you take your first bite.
2. Brisket / Flank (“Nạm”)
- The Cut: Cuts from the lower chest or abdominal muscles containing striated muscle fibers interspersed with ribbons of collagen and fat.
- The Science & Culinary Role: Brisket is cooked in the broth for hours. This long, low-temperature braising transforms tough structural collagen into rich gelatin while keeping the muscle fibers tender. It provides a deeply savory, beef-forward bite that grounds the bowl.
3. Fatty Brisket (Gầu)
- The Cut: A specific section of the brisket rich in solid, unctuous fat cap.
- The Science & Culinary Role: Often intimidating to novices, gầu is prized by connoisseurs. When cooked properly, the thick fat layer becomes translucent and tender rather than greasy. It melts slightly in the piping-hot broth, coating the palate and intensifying the flavor of the lean meats and noodles.
4. Tendon (“Gân”)
- The Cut: Beef tendon (typically from the legs), which is almost entirely composed of dense, tough collagen fibers.
- The Science & Culinary Role: Tendon requires hours—sometimes separate pre-boiling—to break down. When cooked correctly, it loses its raw rubberiness and transforms into a translucent, silky, gelatinous treat that offers a springy, bouncy mouthfeel (dai), highly valued in Vietnamese culinary culture.
5. Beef Tripe (“Sách”)
- The Cut: The lining of the beef stomach (often the honeycomb tripe).
- The Science & Culinary Role: Tripe is composed of smooth muscle tissue arranged in a honeycomb network that traps broth like a sponge. It is blanched separately and added right at the end to retain a distinct, crisp, slightly chewy texture that contrasts sharply with the soft noodles and tender meats.
Summary Strategy for your meat lineup
- The Assembly Order: Slice lean meats (tái) paper-thin so they cook instantly under hot broth; slice cooked cuts (nạm, gầu) slightly thicker to provide structural bites.
- The Balance: A classic “phở chín” (cooked) or “phở tái nạm gân” bowl works because it pairs the clean, soft bite of rare beef with the rich, unctuous depth of tendon and brisket.