How to Make Your Pesto a Thousand Times Better
It's all about the method.
Pesto is one of the staple sauces of summer. It's delicious and quick, and a great way to use up any basil lingering in your fridge or growing riotously in your garden. But ever since I watched Samin Nosrat lovingly make pesto in Italy on Salt Fat Acid Heat, using Ligurian olive oil and fresh basil and, crucially, a mortar and pestle, I've been wondering if I'd been missing out on something.
A mortar and pestle, in case you're not familiar, is the traditional way of making all kinds of emulsions and ground spice mixtures. There are a bunch of different kinds, from the Mexican molcajete to the Japanese suribachi, but all of them operate in roughly the same way—you smash and grind the ingredients against the sides and bottom of a coarsely textured bowl using a blunt dowel. The bowl is the mortar, the stick is the pestle. You get it.
Traditional pesto sauce originated from Genoa, the capital of the Italian region of Liguria, which is why basil pesto is also sometimes called pesto alla genovese, and it was traditionally made in a marble mortar with a wooden pestle. These days, most pesto recipes called for a blender or a food processor, which is much faster and more efficient than a mortar and pestle. But traditionalists claim that the flavor is just not as good and, as a woman of food science with access to a test kitchen, I decided I had to investigate.
I started with a recipe for basil pesto that had all the traditional ingredients: toasted pine nuts, Parmigiano-Reggiano, olive oil, salt, garlic, and basil. Then I made pesto twice, using the exact same amounts of the exact same ingredients. One version was in the food processor, and took about two minutes to whizz together. The other version was with a mortar and pestle, and it took a considerably longer time to do, first grinding up the garlic with salt and then adding the pine nuts until they turned into a paste, grinding handfuls of basil and adding cheese before, finally, drizzling in the olive oil.
I really, honestly, didn't want there to be much of a difference. Making pesto the old-fashioned way is quaint, but it's a lot more time-intensive, not to mention a real workout for your arms. I wanted it to be one of those things where the difference was slight, only noticeable to a discerning palate, so I coould continue to blissfully live my life throwing my pesto ingredients in the food processor, and not worry that I was missing out on much.
But that was not the case. The difference between the two pestos was stark. It was almost like two totally different sauces. The emulsion of the version made with the mortar and pestle was creamy, rather than loose or oily. It smelled incredible. The basil wasn't broken up as evenly, which gave it an entirely different texture. And the taste was incredible. It was, far and away, the best pesto I had ever made, even though not a single ingredient was different from the version I made in the food processor.
Don't get me wrong, the food processor version is fine. If I had just made and tasted that, I wouldn't have been unhappy. But compared to the fragrant, intensely flavorful pesto in the mortar and pestle, it was desparately inferior. Just breaking down the ingredients by hand rather than machine made the sauce into something completely different, and much, much better. That's the bad news. But the good news is: Want to make your pesto so much better? Just grab a mortar and pestle.