Pesto Genovese
Pesto Genovese should taste of fresh basil first, with garlic, nuts, cheese and olive oil holding it up. It is a cool emulsion. Heat is useful later in the pasta pan, not while the basil is being worked.
A fine but perceptibly textured paste, fluid enough to coat without becoming an oil slick.
Fresh, aromatic and savoury, with garlic present but not raw and aggressive.
What the record supports.
Modern pesto Genovese is closely tied to Liguria and the mortar tradition. The familiar ingredient set is basil Genovese, pine nuts, garlic, extra-virgin olive oil, Parmigiano Reggiano, aged sheep's cheese and salt.
Related Ligurian pounded sauces predate the modern formula. That does not make every green blender sauce historically interchangeable with pesto Genovese.
Every ingredient has a job.
Basil
Young fragrant leaves give the sauce its defining aroma and colour.
Pine nuts and garlic
Nuts provide body; garlic gives warmth without taking over.
Two cheeses
Parmigiano supplies savoury depth and Pecorino adds sharper sheep's-milk character.
Olive oil
Oil carries aroma and loosens the pounded paste into a coating sauce.
Build it in order.
Tender locally grown basil works when Basilico Genovese DOP is unavailable. Use good extra-virgin olive oil and freshly grated hard cheese; bagged pre-grated cheese dulls the texture.
- 01
Chill the mortar or processor bowl and dry the basil thoroughly.
- 02
Crush garlic with salt, then pine nuts. Add basil in batches and work quickly without cooking it through friction.
- 03
Fold in finely grated cheeses, then stream in olive oil until the pesto is coarse and spoonable.
- 04
Loosen with warm pasta water only when tossing with pasta. Keep the pesto away from direct pan heat.
Pasta that helps.
- Trofie
- Trenette or linguine
- Gnocchi
- With potato and green beans in the Ligurian manner
Substitutions
Walnuts make a useful basil sauce but not traditional pesto Genovese.
Grana Padano can replace Parmigiano with a milder result.
A small processor is practical if pulsed cold and briefly.
Common mistakes
Processing until the basil warms
Adding pesto to a fiercely hot pan
Leaving wet leaves to dilute and darken the sauce
Pouring in oil until all texture disappears
Storage and freezing
Press a thin film of oil onto the surface, cover and refrigerate for 2 days.
Freeze without the cheese for best aroma, then add cheese after thawing.
Do not reheat pesto alone. Warm it through by tossing with hot pasta and a little pasta water off the heat.
Potato and green beans are an established Ligurian pasta accompaniment.
Rocket, spinach and coriander versions are modern herb sauces and should be named accordingly.
Put the technique to work.
Sources and method
DocumentedPesto al Mortaio traditionTraditional ingredient set and mortar practice