Vol. VI · Proteins and Heat Plate 4 of 11muscle, fibres, connective tissue, grain, slicing, tendernessMT

Muscle.

A steak is a bundle of long fibres all pointing one way. Cut along them and you chew long strings; cut across them and every strand is as short as the slice is thick.

Meat is skeletal muscle. Each muscle is made of long cells, the fibres, each as thin as a hair and up to several centimetres long, packed with the contracting proteins myosin and actin. Fibres are wrapped in bundles by thin sheets of connective tissue — mostly collagen — and the bundles in turn are wrapped into the whole muscle. All the fibres run the same way, which shows on a cut surface as the grain.

Tenderness depends on three things: how tough the fibres themselves have become (cooking tightens them, VI.5), how much connective tissue holds them (VI.6), and how long a piece of fibre you have to chew through. The cook controls the last with the knife. The workshop shows a slice cut at different angles to the grain.

Below: fibres running at the angle you choose to the cut, and the length of each strand in a slice of the thickness you choose.

What you will learn

Describe the structure of muscle.
Find the grain of a piece of meat.
Explain why cutting across the grain tenderises.
Relate structure to tough and tender cuts.

Workshop

Fibres at the chosen angle to the knife. A fibre crossing a slice of thickness d at angle θ is d ÷ sin θ long: shortest when θ = 90° (straight across the grain).

The knife as tenderiser

Cut a 5 mm slice straight across the grain and every fibre in it is 5.0 mm long: your teeth only have to part short stubs. Cut nearly along the grain and the strands are 28.8 mm long, 5.8 times longer — the same meat now chews like string. Flank steak, skirt and brisket, which have long, coarse fibres, are the classic cases: sliced thinly across the grain they are tender; sliced with it, tough.

Chinese cooks apply the rule before cooking: beef for stir-frying is sliced thinly against the grain (横切牛肉) so the slices stay tender in the wok, and pork for shredding is cut along the grain (顺丝) so the shreds hold together. Find the grain by looking at the fine parallel lines on the surface; on a large roast it may change direction from one muscle to the next, so turn the joint as you carve (XVIII.10).

At the stove

Take a piece of flank or skirt steak, find the grain, and cook it as one piece. Cut half into thin slices across the grain and half along it, and taste one of each.

A rule of Chinese knife work says 横切牛羊竖切猪: beef and lamb across the grain, pork along it — because beef and lamb fibres are coarser and pork's finer and more tender.

Terms

Muscle fibre: A single long muscle cell, packed with contracting proteins.
Connective tissue: Collagen sheets wrapping fibres, bundles and whole muscles.
Grain: The direction the muscle fibres run, visible as fine lines.
Across the grain: Cutting at right angles to the fibres, so each strand is short.

Cut across the grain and every strand is only as long as the slice is thick.

Sources

H. McGee, On Food and Cooking: The Science and Lore of the Kitchen, 2nd ed., Scribner, 2004.