Brow Beat

The Absolute Best Way to Make Pesto, According to So Many Tests

On a marble countertop, six globs of pesto, labeled "Chef's Knife," "Blender," "Mezzaluna," "Food Processor," "Mortar," and "Immersion."
Ella Quittner

Maurizio Valle makes a lot of pesto—about 100 batches each year, if he had to guess.

Valle, 77 and a Pesto World Championship finalist, lives in Genoa (the capital of Liguria and the capital of pesto) with a collection of 30-some mortars and pestles, including a few dating back to a 17th-century convent. The mortar he selects to demonstrate his signature technique over video chat is made of marble with four docks jutting out around its top, meant to remind the user to turn it every so often for the smoothest-possible pesto.

I got in touch with Valle, one of the “grandpas” featured in Vicky Bennison’s James Beard Award–winning Pasta Grannies, as soon as I knew I’d be addressing pesto for my latest round of Absolute Best Tests, suspecting he might have a hot take (or 10). But while his technique is wildly consistent across every batch he makes—mortar and pestle only; garlic first, then basil, then nuts, then cheese, then oil stirred in with a spoon—Valle has only one hard and fast rule when it comes to others making pesto: Don’t skip the garlic.

A cutting board with garlic, basil, nuts, and grated cheese.
Ella Quittner

According to Saveur, the earliest recipe for pesto genovese—Valle’s specialty—appeared in Giovanni Battista Ratto’s La Cuciniera Genovese in 1863. The word pesto itself, from “pestare,” meaning to crush in Italian, was apparently entered in Giovanni Casaccia’s Genovese-Italian dictionary in 1876. Nearly 150 years later, at least in the U.S., it’s become something of a catch-all for basil-based sauces made any number of ways: in a blender, in a food processor, with a half-moon rocking blade that will be seriously hard to fit onto your magnetic knife rack.

As it’s come to my attention that many of my city-dwelling peers lack a mortar collection like Valle’s, I tested a handful of the most popular ways to make pesto, to determine the pros and cons of each.

Controls & Fine Print

Ingredient ratios for basil pesto vary wildly across the web, with some calling for four times as many pine nuts as others. For each trial, I used a ratio close to Maurizio’s in Pasta Grannies, which I scaled way down per batch, as pine nuts are roughly the price of solid gold:

• 1 clove garlic
• 1/2 teaspoon salt (Valle calls for rock salt, to give you traction with the pestle; I used coarse kosher)
• 3-ish cups basil leaves (if, like me, you can’t get the sweet, young basil grown in Prà that Valle swears by, he suggests looking for bunches with small, tender leaves)
• 3-ish tablespoons Italian pine nuts, untoasted (in one round of trials, I’ll cop to having used walnuts in lieu of pine nuts—see the gold thing above—but I’m pleased to report that the swap produced an equally delicious, even nuttier pesto)
• Heaping 1/3 cup grated cheese (a mixture of Parm and Pecorino; Maurizio calls for 4 tablespoons 18-month or older Parmigiano Reggiano, plus 1/2 tablespoon Pecorino Sardo)
• 1/3 cup mildly flavored extra-virgin olive oil

In each round of trials, I tested seven ways to arrive at pesto:

1.    Mortar and Pestle
2.    Immersion Blender
3.    Mezzaluna
4.    Chef’s Knife
5.    Food Processor, Adding Basil Initially (pictured)
6.    Food Processor, Adding Basil at the End (not pictured)
7.    Blender

Key Takeaways

Mortar & Pestle

A mortar and pestle is the absolute best way to make pesto, which will be unsurprising to anyone who has had the pleasure of FaceTiming with a Pesto World Championship finalist. The resulting sauce was especially creamy, thanks to proper emulsion, and had the most basil-forward flavor of the bunch. Its oil barely seeped away from the pesto as it sat, and no single fleck or chunk remained decipherable when all was said and pestled. A few tips from Valle: Add the basil before the pine nuts, so the nuts can leech up any water released by the basil. Use a circular motion to blend the ingredients within the mortar (rather than an up-and-down pounding). And stir in the oil with a spoon rather than mixing it in with the pestle, so the wood doesn’t affect its flavor.

Click here for the mortar and pestle method.

Immersion Blender

I’m as shocked as a bunch of blanched broccoli to reveal that an immersion blender produces a sleeper-hit pesto—second in texture and flavor only to the mortar’s spoils. While plunging such a tool into a Weck jar of basil, pine nuts, and salt is awkward and unwieldy at first, the blades produce a much finer chop than either a standard blender or a food processor. And once you toss in grated cheese and oil, you’ll forget all about feeling like you’re excavating an oversized cavity. In discussing this unexpected success with Valle, Bennison, and Bennison’s colleague Livia De Giovanni, someone posited an interesting theory: The flavor might’ve remained fresher and sweeter than that of the other blended batches because an immersion blender’s motor is far above what’s being blended, unlike a food processor’s motor, a heat source that sits just below the contents.

Click here for the immersion blender method.

Hand-Chopping

Hand-chopping pesto is great in a lot of ways—it evokes the term “elbow grease,” and provides an excuse to ignore texts for 20 minutes—but it doesn’t produce the world’s smoothest pesto. Using a sharp blade, as on a chef’s knife or mezzaluna, to pulverize little bits of basil, garlic, and pine nuts until you can’t remember your own name does however create pesto with an interesting flavor. If mortar-pesto and immersion blender–pesto were the harmonious chorus of a quartet, hand-chopped pesto would be a song belted by a lead vocalist, supported by a guitarist, and punctuated by a sexy drummer who’s always taking two minute solos. (Garlic’s the hot drummer, keep up.)

Compared to the mezzaluna, the chef’s knife helped me get the pine nuts and garlic a hair finer. When things in each batch got pretty close to mince-mode, the stubborn straggler pieces would scurry away from the mezzaluna’s blade as it came down on them, narrowly avoiding being chopped in two.

If you’re into a chunkier pesto and like to appreciate the individual flavor of each component, hand-chopping could very much be for you.

Click here for the chef’s knife method.
Click here for the mezzaluna method.

Food Processor

I use my food processor for pretty much everything short of talk therapy, so am disappointed to report that it’s only good, not great, for making pesto. Its blades were able to achieve a decent mince, though it wasn’t nearly as fine as that of the immersion blender. And while the oil initially appeared to be well combined, it separated from the solid components somewhat readily.

With this tool, I did two separate trials: One called for the basil upfront and cheese last; the other called for the basil after the cheese, nuts, and garlic had already been blended. Interestingly (this is interesting, right???), the basil-first batch had a better texture, a more even blend. Perhaps as Valle notes when describing his mortar method, crushing the basil earlier allows the nuts to absorb their liquid, creating a creamier mouthfeel.

Click here for the food processor (basil to start) method.
Click here for the food processor (basil to finish) method.

Blender

I used a vintage Osterizer blender for my trial, and I imagine things would’ve gone entirely differently with one of those hulking Vitamixes. As it were, my blender pesto was fine (as in, I dipped many tortilla chips in it for days to come and didn’t complain once), but had the least consistent chop of all the motorized methods. Which is not to say some components weren’t super fine—they were—it’s just that other components may as well have come from the hand-chopped batches. The blender also required double the volume of recipe for the blades to engage with the contents and, hello, have you seen the price of pine nuts?

Click here for the blender method.

Methods

Behold, all of the methods tested, in rough order of most to least delicious pesto produced. (I’d happily take any, for the record, if you’re thinking of having me over for a socially distant dinner. Please make focaccia too!) For ingredient ratios, check out the Controls & Fine Print section above.

Mortar & Pestle

Adapted from Valle’s recipe in Pasta Grannies.

1. Use a mortar to crush garlic and salt into a paste.
2. Add the basil, and move the pestle in a circular motion around the inner rim of the mortar to crush, rather than pounding it in an up-and-down motion.
3. Add the pine nuts, and combine into the garlic and basil in the same way. Repeat with the cheese until you have a thick, bright paste.
4. With a spoon—not the pestle—stir in olive oil.

Immersion Blender

Inspired by this technique on My Food Story.

1. Place all ingredients, except the cheese and olive oil, into a jar slightly wider than the immersion blender. Blend as finely as you can, pausing to scrape out the inside of the immersion blender with a spatula or spoon every so often.
2. Add the cheese and continue to blend, drizzling in the oil.

Chef’s Knife

Adapted from 101 Cookbooks.

1. Use your sharpest chef’s knife to chop the garlic and a small handful of the basil leaves. Once the basil is in confetti-like pieces, add another handful and keep chopping. Repeat until you’ve chopped in all the basil.
2. Once the basil and garlic is in a fine mice, chop in the pine nuts. Get those down to a fine mince, and chop in the cheese. By the time you’re finished, you should be able to use your blade to form a little block of pesto (sans oil) that will hold its shape.
3. To turn this pesto cake into sauce, transfer to a bowl and stir in oil until combined.

Mezzaluna

Adapted from 101 Cookbooks.

1. Rocking the mezzaluna back and forth, chop the garlic and a small handful of the basil leaves. Once the basil is in confetti-like pieces, add another handful and keep chopping. Repeat until you’ve chopped in all the basil.
2. Once the basil and garlic is in a fine mice, chop in the pine nuts. Get those down to a fine mince, and chop in the cheese. By the time you’re finished, you should be able to use your blade to form a little block of pesto (sans oil) that will hold its shape.
3. To turn this pesto cake into sauce, transfer to a bowl and stir in oil until combined.

Food Processor, Adding Basil Initially

Adapted from NYT Cooking.

1. Add the basil, nuts, garlic, and salt to the food processor. Process until all ingredients are finely ground.
2. Drizzle in the oil through the top spout as the motor runs, about a minute, or until the pesto is smooth and fully combined.
3. Add the cheese, and pulse just to combine.

Food Processor, Adding Basil At The End

Adapted from Bon Appétit.

1. Add the nuts, salt, garlic, and cheese to the food processor. Pulse until all ingredients are finely ground.
2. Add the basil and start running the motor, drizzling in the oil through the top spout, about a minute, or until the pesto is smooth and fully combined.

Blender

Adapted from this Genius Danny Bowien pesto recipe.

1. Add the nuts, salt, and a bit of oil to the blender. Blend for a few moments until well combined.
2. Add the basil, garlic, and remaining oil. Continue to blend until the mixture is smooth.
3. Add the cheese and pulse until homogenous.

Two bunches of basil, the stems submerged in glasses of water while the leaves billow above.
Ella Quittner

A Note On Basil & Pesto Storage

According to former Food52er Sarah Jampel, the best way to keep bunches of basil fresh is to store on the countertop with the stems in a bit of water, like a bouquet of flowers. (Marcella Hazan suggest this, too, in Marcella Cucina. She recommends keeping the basil somewhere cool, but not a refrigerator.)

If you’re not planning to use it immediately, you can cover pesto with a little extra oil and store in an airtight container in the fridge for a few days, or freeze it into cubes using an ice tray, then transfer to an airtight freezer bag for a few weeks.

More from Food52:

Life After Layoffs: How Empanadas Gave Me A Sense Of Belonging
The Summery Vegetable Soup That Makes Itself
For the Easiest Fruit Jam, Skip the Stove—and the Sugar
How to Tell if an Avocado Is Bad
Your 2 Best Eaten-While-Typing Lunches
Let Mascarpone Luxe Up Mushroom Pasta & So Much More