Pasta al sugo needs five ingredients and about 30 minutes: 400 g of pasta, 700 g of tomato passata, one clove of garlic or half an onion, 4 tablespoons of extra virgin olive oil, fresh basil and salt. The secret is not an ingredient. It is simmering the sauce slowly for at least 20 minutes and finishing the pasta inside the pan with the sauce, not on the plate. These quantities serve 4 people.

Which tomatoes should you use for pasta al sugo?

You have three good options, and each gives a slightly different result:

  • Tomato passata (700 g bottle): smooth, ready to use, the everyday choice in Italian homes.
  • Whole peeled tomatoes (two 400 g cans): crush them by hand or with a fork for a sauce with more texture. San Marzano type tomatoes are sweeter and less watery.
  • Fresh ripe tomatoes (1 kg, in summer only): blanch for 1 minute in boiling water, peel, remove the seeds and chop.

Avoid pre-diced canned tomatoes. They are often treated with calcium chloride to keep the cubes firm, which means they never break down into a proper sauce.

Garlic or onion: which one is right?

Both are traditional, and they give two different sauces. Garlic is the faster, sharper, southern Italian version: one whole clove, lightly crushed with the side of a knife, sizzled in the oil for 1 minute over low heat and removed before serving if you prefer a milder taste. Onion gives a sweeter, rounder sauce: half a white or golden onion, finely chopped, softened in the oil for 5 minutes over low heat until translucent, never browned.

Pick one. Using both is not wrong, but the flavours compete and the tomato ends up in the background.

How long should tomato sauce cook?

Twenty to 25 minutes over low heat, with the lid half on, stirring every few minutes. Pour the tomato into the pan with the garlic or onion, add a teaspoon of salt, and wait. In 20 minutes the sauce reduces by about a quarter, the colour shifts from bright orange-red to a deep red, and a little oil rises to the surface. That is the sign it is done.

A raw tomato sauce cooked for 5 minutes tastes acidic and watery. If your sauce still tastes sharp after 20 minutes, the tomatoes were probably not very ripe: add a pinch of sugar, no more than half a teaspoon, or a small piece of carrot while it simmers. Tear 6 to 8 basil leaves in by hand at the end, with the heat off. Cooked basil loses its perfume in minutes.

How do you cook the pasta and combine it with the sauce?

Use 1 litre of water for every 100 g of pasta, so 4 litres for this recipe, and add 10 g of coarse salt per litre once the water boils. Spaghetti, penne and rigatoni all work well with a plain tomato sauce.

Drain the pasta 1 minute before the time written on the package and keep a cup of the cooking water. Tip the pasta straight into the pan with the sauce, turn the heat to medium, and toss for 1 minute, adding a splash of pasta water if the sauce looks tight. The starch in the water binds the sauce to the pasta and gives it a glossy coating. This single minute in the pan is what separates pasta al sugo from pasta with sauce spooned on top.

How do you serve it, and which variations work?

Serve immediately with grated Parmigiano Reggiano or pecorino, a few fresh basil leaves and a thread of raw olive oil. From here the same base becomes several other classic dishes: add a dried chilli with the garlic and you have penne all'arrabbiata; add a knob of butter at the end for a rounder, sweeter sauce; add capers, black olives and a little anchovy for a southern style sauce.

The four mistakes that ruin pasta al sugo

  • Heat too high. The sauce sputters, sticks and turns bitter at the edges.
  • Cooking time too short. Under 15 minutes the sauce stays acidic and thin.
  • Rinsing the pasta. It washes away the starch that helps the sauce cling.
  • Too much sauce. In Italy the pasta is coated, not drowned: about 150 g of sauce per 100 g of pasta is plenty.