Rigatoni

Rigatoni is dried durum wheat pasta extruded as a cylinder with ridges running parallel to its axis, then cut at a right angle. Outside diameter runs 12 to 15mm, length 40 to 45mm, wall thickness 1.2 to 1.5mm. The name comes from rigato, ridged.

Each of those numbers does a job. The thick wall lets the tube hold its own shape when cooked, while a thin-walled tube flattens under a fork and becomes a ribbon. The wide bore lets sauce move into the tube while you toss it in the pan, and stay there. The ridges, usually twelve to twenty on a standard rigatone, add roughly 25% more contact surface than a smooth tube of the same gauge, and more importantly they create channels where sauce parks instead of washing off.

The straight cut is the detail nobody thinks about and the one that matters most. A tube cut at a right angle presents two round, fully open mouths and sauce enters from both. A tube cut on the diagonal, like penne, presents two ellipses that tend to point downward in the pan and drain themselves. That is why the same carbonara tastes richer on rigatoni than on penne with an identical sauce.

Rigatoni is about chew and volume rather than flavour. A properly cooked one gives real resistance, because the thick wall means there is a lot of pasta between your teeth, and each piece carries a mouthful of sauce inside it, so the eating rhythm is very different from a long strand: bite, then a small flood.

The wheat flavour depends on the maker. Slow-dried bronze-cut rigatoni tastes nutty and faintly sweet and holds a chalky centre at the wall. Fast-dried supermarket pasta tastes of very little, though on a heavy ragù you will notice it less than you would on a bare olive-oil sauce.

The visible difference is worth knowing: pick up a piece of good rigatoni after tossing and the ridges should still be coated, with sauce visible inside the tube. If the sauce has run off and pooled in the bowl, either the pasta is smooth-surfaced or the sauce is too thin for the shape.

Use plenty of water, four quarts per pound, because the shape is bulky and the tubes wedge inside each other when crowded. Salt once it boils.

Drain two minutes short of the box time and finish in the pan with a ladle of pasta water. On this shape that step is not a flourish, it is when sauce actually gets inside the tubes. Move the pan back and forth rather than stirring with a spoon, which cracks the walls.

The sauces that suit rigatoni have two components: something creamy and something in small pieces. Carbonara, where the egg and pecorino emulsion grips the ridges while strips of guanciale end up inside the tubes. Amatriciana and gricia for the same reason. Rigatoni con la pajata, the Roman classic made with milk-fed veal intestine that thickens into a sauce as it cooks. Umbrian norcina with crumbled sausage and cream. Pork ragù, provided the meat is cut small enough to enter the bore.

Baked, rigatoni is hard to beat: the ridges hold béchamel, the tubes fill with ragù and the thick wall survives forty minutes in the oven. What it does not suit is anything thin: aglio e olio, clam sauce, a loose pesto. A sauce without body runs straight off the ridges and sits at the bottom of the bowl.

Sealed, in a cupboard away from light, heat and damp, a pack of dry rigatoni runs to the date printed on the box, usually two or three years out. That date belongs to the maker; what you can observe is that the smell of wheat fades over time and the pasta tastes of less. The cupboard directly above the hob is the worst spot in the kitchen, because heat and steam get into the box. Once the pack is open, tip it into an airtight jar: open bags in a warm kitchen are where pantry moths get in during summer.

Cooked and dressed, rigatoni keep two days in the fridge at 4 C under a cover, and they keep drinking the sauce, swelling and softening a little each day; a spoonful of water in a hot pan brings them back. Unlike long pasta, the shape survives the freezer once cooked and dressed, since the tubes hold their walls, and it reheats in a 180 C oven. An assembled but unbaked tray freezes too and goes in straight from frozen with twenty minutes added.

Hold a piece up to the light. The ridges should be deep and sharp with a live crest rather than a rounded one, and the mouths of the tube should be true circles with a clean edge: ovalled or squashed ends come from a bad cut and stay shut in the water. Pinch the wall between two fingers, since anything under a millimetre collapses when tossed with sauce. The colour is matt ivory and the surface leaves a floury trace on your fingertips; bright glossy yellow means a teflon die and fast drying, and sauce slides off it.

On a foreign shelf rigatoni sits next to shapes that are not the same: penne rigate are cut on the angle to a point, tortiglioni have ridges that spiral, and in the United States a similar tube is often sold as mostaccioli. The label words that matter are bronze die (trafilata al bronzo) and slow dried, with protein above 13 percent and a declared cooking time of 11 to 14 minutes. A handful of tubes split lengthways in the pack points to aggressive drying. Bronze-die imports cost two to three times own-label.

In the US, De Cecco and Barilla rigatoni sit in every supermarket at $1.50 to $3 a pound. The worthwhile step up is Rummo, Garofalo, Montebello or Mancini at $4 to $6. Bronze-cut Gragnano IGP and artisan producers (Faella, Setaro, Gentile, Afeltra, Verrigni, Benedetto Cavalieri, Rustichella d'Abruzzo) run $7 to $14 a pound through Eataly, Gustiamo, Market Hall Foods and Amazon.

In the UK, Waitrose, Ocado and Sainsbury's carry De Cecco and Garofalo at £2 to £4.50 per 500g, so £4 to £9 per kilo; Natoora, Vorrei, Vallebona and Seggiano ship artisan Gragnano at £8 to £18 per kilo. Italian prices run €1.10 to €2.20 a kilo for supermarket brands and €6 to €14 for artisan.

On the pack, check three things: 'trafilata al bronzo' or 'bronze cut'; a stated slow-drying time; and the look of the ridges through the window, which should be sharp-crested and deep rather than soft and rounded. Pale matte tubes with a dusting of semolina in the bag are the ones you want.

Rome, and specifically Testaccio. The district grew around the municipal slaughterhouse that opened in 1891, and its cooking is built on the quinto quarto, the offal cuts paid to the workers as part of their wages. Rigatoni con la pajata is the emblem of that kitchen, and the old trattorie between Via Galvani and Via Marmorata still serve it the traditional way. The same streets are the right place for carbonara on rigatoni.

Pigneto and San Lorenzo, on the eastern side of the city, are where the younger Roman kitchens work, usually with named artisan pasta and often with rigatoni as the default for carbonara and amatriciana.

For the pasta rather than the dish, Gragnano near Naples is the trip worth making: the historic factories along Via Roma run tours and sell direct, and their rigatoni has a noticeably thicker wall and a longer cook time than northern industrial pasta.