Dried Pasta.
"Four litres of water for every 400 grams of pasta" is a habit, not a law. Less water cooks pasta just as well and makes better water for the sauce.
Dried pasta is made from durum wheat semolina, a hard, high-protein, yellow wheat whose gluten forms a firm network around the starch (VI.10). Extruded through dies — bronze ones leave a rough, sauce-gripping surface — and dried slowly, it keeps for years. In boiling water it absorbs about 1.4 times its weight, the outside gelatinises first (VII.1), and some starch washes off into the water. "Al dente" — to the tooth — is pasta taken out while the very centre is still a little firm, a thin pale line when bitten, because it keeps cooking in the sauce.
The traditional large pot (about a litre per 100 g) has a reason: when cold pasta goes in, a big pot drops less in temperature and returns to the boil sooner, and the starch is diluted so pieces stick less. But a smaller amount of water works if you stir in the first minutes, and it has an advantage: the water ends up much starchier, and starchy pasta water is the cook's best tool for binding fat and liquid into a glossy sauce that clings (X.2). Salt is a matter of concentration, not volume: about 1 % seasons the pasta from the inside. The workshop boils pasta.
Below: for 100 g of dried pasta in the water and salt you choose, the drop in water temperature when the pasta goes in (exact heat balance), the starch in the water at the end (about 4 g shed per 100 g, a teaching value), and the salt the cooked pasta takes up with the water it absorbs.
- Describe durum pasta and al dente.
- Choose the amount of water.
- Salt pasta water by concentration.
- Use starchy pasta water in sauces.
Less water, starchier water, same salt
A litre of boiling water per 100 g of pasta cools by about 3.3 °C when the pasta goes in; half a litre by 6.3 °C — still close to the boil, and back within a minute on a decent burner. The half litre ends up at about 8 g of starch per litre against 4: twice as starchy, twice as good at binding a sauce. Salted at 10 g per litre (a teaspoon and a half), the cooked pasta holds about 0.58 % salt — seasoned through, which salting the sauce cannot do. Oil in the water does nothing useful; it floats.
Method: bring the water to a rolling boil, salt it at about 10 g/L, add the pasta and stir for the first two minutes; cook to a minute or two short of the packet time, tasting; save a cup of the water; drain and finish the pasta in its sauce over heat for the last minute with splashes of pasta water, tossing until the sauce turns glossy and clings (cacio e pepe and carbonara depend on it, X.2). Do not rinse pasta for hot sauces — it washes off the starch that helps the sauce cling; rinse only for cold pasta salads.
Cook 100 g of spaghetti in half a litre of salted water in a wide pan, stirring often, and another 100 g in two litres. Compare the cooking time, the stickiness and how milky the water is.
Terms
- Durum wheat
- A hard, high-protein wheat ground to semolina for dried pasta.
- Al dente
- Pasta cooked until just firm at the centre.
- Pasta water
- The starchy cooking water, used to bind sauces.
- Bronze die
- An extrusion die that leaves a rough surface sauces grip.
Sources
- A teaching value chosen for the course: the right order of magnitude and shape, not a measurement of a particular food.
- H. McGee, On Food and Cooking: The Science and Lore of the Kitchen, 2nd ed., Scribner, 2004.