Cuts and Their Uses.
A cow's tenderloin barely moves; its shank carries it about all day. They are the same protein and need opposite cooking.
A carcass is divided into cuts, and the most useful thing to know about any cut is how hard its muscle worked. Muscles of locomotion and support — the shoulder (chuck), the leg (shank), the chest (brisket) — are built with more connective tissue (collagen sheaths around fibres and bundles, VI.6) and coarser fibres, because they bear load all day. Muscles along the spine — the tenderloin, the loin and rib (sirloin, rib-eye, pork loin) — do little work and are fine-grained and low in collagen.
That sets the method. Tender cuts are cooked fast and hot to a precise core temperature and no further: seared, grilled, roasted (Vol. XV), because their fibres toughen and dry as they pass 60–65 °C (VI.5) and there is little collagen to gain. Tough cuts are cooked long and moist until their collagen turns to gelatin (VI.6, XVI.4): braised, stewed, simmered, smoked. Fat helps either way: marbling (fat inside the muscle) lubricates and carries flavour. The workshop compares collagen across six beef cuts.
Below: the collagen content of six beef cuts (teaching values in the measured order), the one you choose highlighted, with its best method.
- Explain why working muscles are tougher.
- Tell tender cuts from tough ones.
- Match a cut to a method.
- Explain what marbling does.
Fast for the lazy muscles, slow for the busy ones
In these teaching values the shank carries about 6 times the collagen of the tenderloin. Below roughly 0.7 % the gain from melting collagen is small and the loss from overcooking the fibres is large, so the cut is cooked fast; above it, hours of moist heat turn a tough cut into the most succulent meat on the animal, while a tender cut cooked that way would just be dry. Middle cuts — chuck, pork shoulder — are versatile: braised whole, minced, or sliced thin across the grain and cooked fast.
The same logic runs through every animal. In pork, the loin and tenderloin are fast cuts and the shoulder, belly and hock slow ones; in lamb, the rack and loin against the shoulder and shank; in chicken, the breast (little-used flight muscle in a farmed bird) against the legs, which carry the bird and are darker, richer and more forgiving (XVIII.7). Chinese butchery adds its own cuts — 牛腩 (flank and belly for braising), 牛腱 (shank, for 卤 and cold slicing), 里脊 (tenderloin, for stir-fries) — and the same rule applies.
At the butcher's counter, sort what is there into "fast" and "slow" cuts by where on the animal it came from. Check the price: tender cuts cost more per kilogram, though the slow ones often taste of more.
Terms
- Working muscle
- A muscle that bears load or moves the animal; tougher and more flavourful.
- Connective tissue
- Collagen sheaths around muscle fibres and bundles.
- Marbling
- Fat inside a muscle, between its fibre bundles.
- Tender cut
- A low-collagen cut cooked fast to a precise temperature.
Sources
- A teaching value chosen for the course: the right order of magnitude and shape, not a measurement of a particular food.
- Differential scanning calorimetry of muscle: myosin denatures around 54–58 °C, collagen shrinks around 60–67 °C, actin around 70–80 °C (A. Wright, I. B. Leach and P. Wilding, "Differential scanning calorimetric studies of muscle and its constituent proteins", J. Sci. Food Agric. 28, 1977; H. McGee, On Food and Cooking, 2004). The course uses midpoints within these ranges.
- H. McGee, On Food and Cooking: The Science and Lore of the Kitchen, 2nd ed., Scribner, 2004.