On the whole, there are basically just two genres of pasta: egg pasta and non-egg pasta. Non-egg pasta is mostly made with durum wheat, egg pasta with traditional wheat (the previous sentences have long tails, in statistical terms). Problem (or delight) is, each genre can be declined in an infinite variety of ways.
The composition and taste of each genre are fixed and identical, although we Italians can bicker indefinitely as to how many eggs per kilo to use (answer: any integer between 5 and 12). One would then expect shape to be but a decoration issue. Nothing could be farther from the truth.
We do not taste pasta with our taste buds alone. Tenacity is also important —hence the obsession with size and cooking al dente— as is texture, hence the many different shapes.
If we were to concentrate on ingredients or taste alone, for instance, pasta al ragù would be essentially the same whether the pasta was stelline (literally, small stars), spaghetti, or tagliatelle. To an italian palate, though, the first combination would be kid gunk, the second a hoax and only the third will be The Real Thing.
Why is it? Tenacity and texture:
- stelline is a minute egg pasta normally used in soups or as kid food; whichever sauce you put on it the gunky, spoon-feeding result is anything but attractive to us
- spaghetti have a blander taste (no egg) and are less porous than egg pasta, so the sauce tends to slip away as you fork up
- tagliatelle are tasty (a good pairing with rich sauces) and porous, so the sauce will literally stick to the pasta.
We use to say that each variety of pasta has “its own” sauce. This is not to be taken literally, but it is a reasonable approximation. To make things more difficult, each “perfect match” will have at least one exception, to the extent that even among Italians some matches are more a matter of opinion or habit than anything else (for instance, all Italy eats spaghetti carbonara, but in Rome you will just as likely be served rigatoni).
How is the poor non-native to find his way in this maze to a proper Italian pasta-sauce combination? Here are a few thumb rules; use them wisely and you’ll be able to fake an Italian ascendant nine times out of ten:
- use a recipe book written by an Italy-grown Italian
- use the variety of pasta the recipe indicates, or another of a similar shape
- ragu (so-called bolognese sauce) only goes with egg pasta, either long or short of stuffed, or with potato gnocchi
- there is no such thing as “spaghetti bolognese”, see above
- for fish sauces prefer thinner long pastas, either egg or non-egg (“spaghettini”, “linguine”)
- thicker long pastas are ideal for thick meat sauces
- sauces with diced vegetables, peas or chick peas are a perfect match for large short pastas where the bits can sneak into: “lumaconi”, “maniche”, etc.; the same could be said for meat sauces, only we don’t do it
- for simple sauces (“aglio e olio”, “pomodoro e basilico”, etc.) or when in doubt, use thick spaghetti
- stuffed pastas are a world apart, do as the recipe says.