Authentic spaghetti alla carbonara has four ingredients besides the pasta: guanciale, eggs, pecorino romano and black pepper. No cream, no garlic, no onion, no parsley. For 4 people you need 400 g of spaghetti, 150 g of guanciale, 4 egg yolks plus 1 whole egg, 100 g of grated pecorino romano and plenty of freshly ground pepper. The only real difficulty is temperature: the eggs must meet the pasta away from the flame, and this article explains exactly how.

Why guanciale and not bacon or pancetta?

Guanciale is cured pork cheek. It has a much higher fat content than pancetta, and that fat melts into a clear, intensely flavoured liquid that becomes the base of the sauce. Pancetta, which is cured pork belly, is an acceptable substitute if you cannot find guanciale. Smoked bacon changes the dish: the smoke covers the pecorino and the result is a different recipe.

Cut the guanciale into strips about 1 cm thick and 3 cm long, removing the hard rind. Put it in a cold, dry pan, without oil, and turn the heat to medium-low. In 8 to 10 minutes the fat becomes liquid and the strips turn golden and slightly crisp. Turn off the heat and leave everything in the pan.

How do you make the egg and pecorino cream?

In a large bowl, combine the 4 yolks and the whole egg with 80 g of the grated pecorino and a generous amount of black pepper, about 2 teaspoons. Whisk with a fork until you have a thick, uniform paste. Then add 1 or 2 tablespoons of the warm guanciale fat from the pan and whisk again: the fat starts to loosen the cream and carries the flavour of the pork into the eggs.

Using more yolks than whole eggs is what gives carbonara its deep yellow colour and rich texture. Whole eggs only make the sauce thinner and paler. Keep the remaining 20 g of pecorino for serving.

How do you combine everything without scrambling the eggs?

Egg yolks begin to set at around 65 °C and are fully cooked at 70 °C. Pasta straight from the pot is close to 100 °C, and a pan that has just left the flame is hotter still. If the eggs touch either of those, you get scrambled eggs with pasta. The technique is built around bringing the temperature down before the eggs arrive.

Drain the spaghetti 1 minute before the package time, keeping a cup of cooking water. Tip the pasta into the pan with the guanciale, with the heat off, and toss for 30 seconds. Then pour in the egg cream and toss vigorously, adding hot pasta water one tablespoon at a time. In about a minute the sauce turns from thick paste to a glossy, flowing cream that coats every strand. Never put the pan back on the flame. If it feels cold, the residual heat of the pasta, around 75 °C, is still doing the work.

If you are nervous about the pan, use the bowl instead: pour the drained pasta and the guanciale into the bowl with the egg cream and toss there. The bowl is at room temperature and there is almost no way to overheat the eggs.

How much salt goes in the pasta water?

Less than usual. Guanciale and pecorino romano are both very salty, so use 7 g of salt per litre of water instead of the standard 10 g. For 400 g of spaghetti that means 4 litres of water and about 28 g of salt. Taste the finished dish before adding any more.

How do you serve carbonara?

Immediately, on warm plates, with the remaining pecorino and another turn of black pepper on top. Carbonara does not wait: after 5 minutes the cream thickens and after 10 it dries out. It cannot be reheated, because any heat above 70 °C will cook the eggs through. Make it when everyone is already at the table.

The five mistakes that ruin a carbonara

  • Adding cream. The egg and pecorino emulsion is the cream. Dairy cream flattens the flavour and makes the dish heavy.
  • Garlic or onion in the pan. They cover the guanciale and the pecorino, which are the whole point of the dish.
  • Pan still on the flame. The eggs scramble in seconds.
  • Too little pasta water. The sauce stays a thick paste instead of flowing.
  • Cold plates and slow service. The cream sets before it reaches the table.