Pasta myths, settled

Pasta attracts myths the way few foods do. Some are kitchen lore handed down as fact, one was written by a trade magazine in 1929, and several get the cause and effect exactly backwards. Here are six of the most repeated, each settled against the historical or physical record rather than the folklore.

"Marco Polo brought pasta back from China"

He did not. An Arab geographer, al-Idrisi, described the Sicilian town of Trabia milling and drying pasta in quantity for export around 1154, and a Genoese inventory listed a basket of macaroni in 1279, both before Polo returned from his travels in 1295. Food historians trace the modern legend to a single source: a 1929 article in an American trade magazine, the Macaroni Journal, which invented a sailor to tell a better story. Pasta is older than the tale and more Mediterranean, with deep roots in Arab-Norman Sicily, not a souvenir carried from the East.

"Put oil in the water so it doesn't stick"

Oil is lighter than water, so it floats in a slick on the surface and never touches the pasta while it cooks. What keeps strands apart is moving them, a stir in the first minute or two while a real boil holds, back when the surface starch is still setting. The oil only meets the pasta at the very end, when you drain it through that surface film, and then it does the one thing you did not want: it coats the noodles so the sauce slides off and pools at the bottom of the bowl.

"Rinse it after you drain it"

Only if you are about to serve it cold. The cloudy film on a just-drained noodle is starch, and that starch is what a sauce grips, so rinsing it away leaves the sauce nothing to hold. The word pasta means paste, and the paste is the point. The exception proves the rule: for a cold pasta salad you do rinse, because that same surface starch turns sticky and gluey as it cools, so you wash it off and trade cling for separation.

"Make the water as salty as the sea"

A useful exaggeration, not a measurement. Real seawater runs about 3.5 percent salt by weight, by the US Geological Survey's reckoning, while well-salted pasta water sits closer to 0.5 to 1 percent, four to seven times less. The reason to salt at all is that pasta is bland on its own and takes its seasoning from the inside as it drinks up water, so water that is too faint leaves the pasta flat under any sauce. Take it to true ocean strength, though, and the dish is inedible. The honest instruction is by weight, not by sea.

"Throw it at the wall to see if it's done"

This tells you the opposite of what you want. Physicists have actually tested it: a strand sticks reliably only once it is overcooked, and at the al dente window a thrown piece is little better than a coin flip. So the wall confirms doneness only after you have already gone past it. The instrument that works is the one in your hand, a strand bitten in half. The wall just gives you something to clean.

"Never break the long pasta"

Whether to break it is a question of tradition, and Italian tradition is firmly against snapping spaghetti before it meets the pot. The more interesting fact is physical: a dry strand almost never breaks into just two pieces. Bend it until it snaps and the release sends a shock wave racing back down the rod, bending it further and breaking it again, which is why you get three or four flying pieces instead of two. Two physicists explained this in 2005 and were handed an Ig Nobel Prize for it; in 2018 a team at MIT found the only reliable way to force a clean break in two, which is to twist the strand hard before you bend it. The shape is engineering all the way down, even as it fails.