Pesto Without Parmesan

I want to make an argument about pesto. The argument is small, and it is one of those that, the first time you hear it, sounds obviously wrong. By the time you have made pesto the way I am about to describe two or three times, it will sound obvious.

The argument is this. Parmesan does not belong in the mortar.

The cheese, if you are using cheese, goes on the pasta. Not in the pesto. The pesto is the pesto. The cheese is the cheese. You put them together on the plate.

I did not invent this. I learned it from a woman in Camogli named Edda, who has been making pesto for fifty years and corrected me with a wooden spoon when I was twenty-six. I have written about her elsewhere — the full story of that afternoon is in the postcards. What I want to do here is explain why she was right, because it took me about eight years and a hundred pestos to understand it.

The standard American pesto recipe — call it the Genoese-by-way-of-Trader-Joe’s version — puts six ingredients into a food processor: basil, pine nuts, garlic, parmesan, salt, olive oil. You run it on continuous for thirty seconds. You scrape down the sides. You run it for another fifteen. You decant it into a jar. It tastes like pesto. It is not bad. It is, if you have ever made it the other way, also not pesto.

Here is what’s happening when you process all six things together. The cheese, which contains fat and protein, emulsifies with the olive oil and starts to bind the whole mixture into a paste. That paste, by virtue of its emulsification, holds a uniform flavor profile from first bite to last. Every spoonful tastes the same. The cheese is everywhere — in the basil, in the pine nuts, in the oil. It carries the dish.

The Ligurian version, made with a mortar and a wooden pestle and finished by folding the cheese in at the plate, is a different geometry. The basil stays basil. The pine nuts stay pine nuts. The garlic — ground first, with coarse salt acting as an abrasive — stays garlic. The olive oil is added at the end, in a slow stream, to loosen the paste, never to bind it. What lands on the pasta is a mixture of distinct elements, each retaining its own integrity. The cheese is grated on at the moment of serving and folded in by the heat of the just-drained pasta itself. The result is layered: you taste the basil, then the garlic, then the pine nuts, then — late and warm and savory — the cheese. The dish has texture. The dish has narrative.

There is a second reason for the rule, and Edda explained it to me by tapping her spoon against the rim of the mortar. Parmesan, once introduced into a paste with oil and salt and basil, begins to break down. Within twenty-four hours its proteins denature, its fats migrate, its texture turns gritty. The pesto you made on Saturday and tasted on Sunday does not taste like the pesto from the night before — it tastes like a slightly bitter, slightly mealy version of itself. Keep the cheese out of the mortar, and the pesto holds for a week in the fridge with nothing more than a film of olive oil across the top to keep it from oxidizing. The cheese, kept separate and grated to order, lasts indefinitely.

These two things — the geometric argument about flavor layering, and the practical argument about shelf life — are sufficient on their own. The third reason is the one I find most interesting.

It is about what a recipe is for.

A recipe, in the American food media model, is a set of instructions that produces a uniform result. It assumes the dish should be the same every time. The food processor is the perfect tool for this — it homogenizes, it standardizes, it produces consistency.

A recipe, in the Italian nonna model, is a set of intentions. The dish should reflect the day. The basil that came in this morning is not the basil that came in last week. The pine nuts from this batch are slightly oilier than the previous one. The cheese — the cheese is a finishing element that gets folded in at the table, by the eater, on the eater’s own plate. It is the eater’s contribution to the dish. The recipe ends when the cook delivers a bowl of pasta and a small bowl of grated cheese. The diner finishes the dish.

This is a small thing. It is also the entire game.

When you keep the cheese separate, you give the eater a role in their own dinner. That role used to be ordinary — every Italian-American household kept a grated parmesan dish on the table, and every diner reached for it. Somewhere in the last forty years, in the move from family kitchens to processed-from-the-jar pesto, we automated the diner out of the loop. The dish arrives complete. There is nothing for the eater to add. The cook has decided how much cheese, where, when. The diner just eats.

I think we lost something there. Not a flavor — the flavor is roughly comparable. We lost a small ritual of participation. The grating of cheese over a steaming bowl is a tiny gesture, but it makes the meal a meal instead of a delivery. It is the same impulse that makes us light a candle at dinner, or pour from a carafe instead of a bottle. It costs nothing. It changes everything.

There is also — and this is the part that probably belongs in the manifesto, but I will say it here — a useful corollary for those of us who happen not to be using cheese. If the parmesan is structurally separate from the pesto, then the absence of parmesan is also structurally separate. The pesto recipe does not contain a hole where cheese should be. The pesto contains basil, pine nuts, garlic, salt, oil. That’s the pesto. Whether you grate parmesan, pecorino, a cashew-and-nutritional-yeast blend, or nothing at all over the finished plate is a separate question — answered after the pesto is already made.

This is the same principle as the milanesa, the moussaka, the cassoulet. The dish is the dish. The dish has a structure. The structure does not depend on any particular topping. The pesto is the pesto. The cheese is the cheese. You put them together on the plate.

I have made a thousand pestos since Camogli. I have made them in food processors when I had no mortar, in mortars when I had time, with cashews and nutritional yeast for friends who don’t eat cheese, with pecorino sardo when I was in a Roman mood, with no cheese at all most nights because most nights I do not feel like grating. Edda’s rule has survived every variation. The pesto is the pesto. Whatever finishes the plate is the eater’s decision, at the table, after the pasta has hit the bowl.

If you have a mortar, use it. The motion is a slow press-and-rotate, not a pound. The garlic goes in first, with coarse salt. Then pine nuts. Then basil, a handful at a time. Olive oil at the end, in a trickle. Five minutes of work, real work, with your shoulder. If you do not have a mortar — most of us don’t — use a food processor, but pulse, never run, and stop the moment the basil is crushed and not a second after. Decant. Cover with oil.

Whatever you grate over the bowl, do it at the bowl. Not in the jar.

That’s the entire argument.

— Alexandre Teulade Washington, D.C.