Hand-Pulled Noodles.
A noodle maker swings a rope of dough, folds it, swings it again. After eight pulls there are 256 strands; after thirteen, 8 192, each finer than a thread.
拉面 (also 抻面) turns a single piece of dough into noodles without a knife. A firm dough of high-protein flour and water, with alkali — traditionally 蓬灰, ash from a desert plant, now usually a carbonate solution (XXI.7) — is kneaded long and rested repeatedly until it is smooth, strong and, above all, extensible: it can be stretched a long way without tearing and without springing back. The alkali tightens the gluten into a springy but slippery network; rest lets the gluten relax so it stretches (XXIV.4).
The pulling is geometry. The rested dough is rolled into a rope, swung and stretched to the width of the cook's arms, folded in half so the ends meet, and pulled again. Each pull doubles the number of strands and, because the volume is conserved while the length doubles, halves each strand's cross-sectional area — its diameter shrinks by √2. Lanzhou noodle shops name their widths by how many pulls: thick 大宽 after a few, fine 二细 after about seven or eight, hair-fine 毛细 after nine or ten. The workshop counts the pulls.
Below: the number of strands and the diameter of each after the pulls you choose, starting from a rope of the thickness you choose (exact geometry: strands = 2ⁿ, diameter = starting diameter ÷ 2^(n/2)), with the Lanzhou names for the widths.
- Explain why each pull doubles the strands.
- Calculate strand thickness.
- Make an extensible noodle dough.
- Name the Lanzhou widths.
Double, halve, repeat
From a 24 mm rope, eight pulls give 256 strands about 1.5 mm thick — 二细 territory; ten give 1 024 strands about 0.75 mm — 毛细; thirteen give 8,192 strands about 0.27 mm, the "dragon's beard" (龙须面) of demonstrations. The dough never changes; only the arithmetic of folding does. Each doubling also doubles the length of strand that must not tear, which is why the last pulls need the most extensible dough and the lightest hands.
At home, a simpler 抻面: knead 300 g bread flour, 165 g water, 3 g salt and 2 g of baked soda (XXI.7) into a smooth, firm dough; rest 30 minutes; knead again; rest an hour, oiled and covered; cut into finger-thick strips, oil them, rest again 30 minutes; then hold each strip by the ends and pull gently to arm's length, bouncing it on the counter, fold once or twice and pull again. Boil at once in plenty of water for 1–2 minutes (XXI.7). If the dough tears, it needs more rest; if it springs back, more rest still.
Make a small 抻面 dough and pull one strip with two folds and another with four. Measure the thickness of a strand from each.
Terms
- 拉面 / 抻面
- Hand-pulled noodles, stretched and folded from one dough.
- 蓬灰
- Traditional plant-ash alkali for noodle dough.
- Extensibility
- How far a dough stretches without tearing or springing back.
- 毛细
- Hair-fine pulled noodles.
Sources
- A teaching value chosen for the course: the right order of magnitude and shape, not a measurement of a particular food.