Ramp Pesto

Ramps, a type of wild onion that grows in eastern North America, are one of those vegetables chefs, food writers, and food enthusiasts speak about with a certain breathlessness. That’s both because they’re delicious and because they’re ephemeral; ramps are resistant to cultivation and in season for a very short window of time (typically between mid-April and mid-May).

I’m of two minds about ramps. On the one hand, I'm put off by some of the hype surrounding their annual arrival. On the other, the grumpy New Yorker living deep within my soul is drawn to the idea of traipsing through the woods in search of undiscovered patches of rare seasonal vegetables. Plus, I think ramps are tasty.

So, when Upstate Farms, a farm in upstate New York that supplies restaurants with both cultivated and foraged ingredients, posted on their Instagram account that they were hosting a foraging day that, for $75 a person, included a catered lunch with a guided foraging expedition, my wife and I rented a car, drove a couple hours north, and soon were in the woods standing ankle-deep in a field of ramps.

Upstate Farms is owned by Jan Greer and Mike Kokas, who founded the farm in 1989. They supply some of New York’s best restaurants, including Stone Barns at Blue Hill (where our colleague Genevieve was a cook). Foraging is a way for them to supplement their commercial produce with ingredients that are wild, explicitly of the local environment, and inherently connected to the season. After hearing them talk about foraging for several hours, it became clear the desire to provide people with hyper-local food is as much of a philosophical position as it is an aspect of their commercial enterprise. For Mike especially, it’s also a hobby, and Jan says he’ll disappear into the woods for many hours at a time, emerging with (amongst other things) fiddlehead ferns, morel and oyster mushrooms, stinging nettles, and, of course, ramps.

On this particular day, it was myself and my wife emerging from the woods with ramps: around eight pounds worth.

Making Ramp Pesto

Back home with my ramps, I had to decide what to do with them, and ramp pesto, being one of the most popular ways to prepare them, was an obvious choice.

Serious Eats has a number of recipes which use ramps, and a common thread between these recipes is that it’s important to preserve and highlight the flavor of the ramps during cooking. While they’re quite garlicky and, if treated incorrectly, can be a bit harsh, there’s no point in going to the trouble and expense of buying a relatively rare foraged vegetable just to drown it out with other flavors. My goal was to maintain and even enhance the flavor of the ramps, while creating a sauce that was creamy and savory but also fresh and bright.

While traditional Ligurian pesto is best made in a mortar and pestle, I knew that wouldn’t work as well for ramps. For one thing, the bulb and stem of the ramp is fibrous, and is better processed into a paste to ensure those fibers get sufficiently broken up. That's not to say a mortar and pestle wouldn't work, but for ramp pesto, it'd be a much more exhausting task than busting up delicate basil leaves. A food processor is therefore my tool of choice, and it still produces a truly excellent pesto.

I knew I wanted to use roughly the same sort of formula for making my ramp pesto as Daniel used for his traditional Genovese pesto (nuts, salt, cheese, olive oil, and the green vegetable), so that was my rough guide for developing this recipe, though the ratios, process, and exact ingredients all required tweaking to make a truly exceptional ramp pesto.

The Ramps

How to Clean the Ramps

To wash them, fill your sink or a large bowl with cold water and swish the greens in the water to loosen any dirt and debris. If the water is extremely dirty, empty your vessel and refill it, and then do the same with the bulbs. Make sure to clean the little crevice which forms where the bulb starts to branch into leaves—that dirty little elbow is a magnet for sand and grit, and you’ll want to make sure none of that gets introduced into your pesto.

Blanching the Ramps

One of the first deviations from a classic pesto recipe I made is to blanch the ramp greens. It's a necessary step given the more fibrous texture of ramp leaves (compared to something like basil), softening them and improving the texture of the pesto. It also helps it retain the leaves' vivid green color.

As Daniel noted in his technique piece about blanching, it’s important to shock the greens in ice water immediately after blanching. Don’t just use a bowl filled with cold tap water or run them under the faucet; use actual ice water. It makes a difference that I could clearly see when testing the recipe: The pesto made with blanched greens shocked in ice water was more vibrant in color and flavor than pesto made with ramps I had more lazily cooled with tap water.

While it’s important to blanch the ramp greens, it's equally important not to blanch the ramp's white bulbs. As noted earlier, ramps have a strong, garlicky flavor (it’s part of the appeal!), and you really want to preserve that punch, especially as it’s tempered by the savory nuts and cheese and complemented by the acidity of the lemon. 

Also worth noting: After blanching and chilling the ramp greens, they only need to be gently squeezed of excess water by hand, with no need to exert additional pressure by wringing them out in a towel. If you find that your ramp greens are still kinda soggy when you go to chop them, don’t worry about it! That small amount of extra ramp-infused water will only help to loosen up the pesto, and if you decide to use the pesto to sauce pasta, you’ll want to introduce extra cooking water anyway. Squeezing out the greens as best you can by hand will do the trick and save you some trouble.

Choosing the Nuts

I tested this recipe with pine nuts, pistachios, and walnuts. Which type of nut you want to use really comes down to personal preference, and my wife Andrea’s favorite version—made with walnuts—was my least favorite. The nut that we could both agree on was pistachios.

During testing, I used both unsalted and salted dry-roasted pistachios, and either works. This recipe calls for unsalted, though, since that will allow you to better control the amount of salt. I found that this pesto can handle quite a bit of salt before tipping into over-salted territory—as much as one tablespoon of Diamond Crystal kosher salt (which weighs nine grams and is not the same as one tablespoon of table salt). Season to taste as you see fit, but don't be too afraid of pushing the salt here.

Choosing the Cheese

I tested this recipe using both Parmesan and Pecorino Romano, and the pecorino was the clear winner. The sharp, salty bite of the cheese complemented the other ingredients well, while the sweeter Parmesan was overwhelmed by the other flavors; it certainly wasn’t bad, but the pecorino was both tastier and less expensive.

I grated the cheese using both a handheld microplane grater and by pulsing it in my food processor. The microplaned cheese integrated perhaps a bit better than the food-processed cheese, but it also had a tendency to clump up, especially when my kitchen was hot and humid, and it’s unequivocally more of a hassle to grate it by hand anyways. If you buy a whole block of pecorino, my recommendation is to weigh the amount of cheese you need, pulse it in your food processor until it’s ground into a fine powder, transfer it to a small bowl, and then prepare the recipe as directed after that; no need to clean the food processor after pulsing the cheese, since whatever residue is left will just get incorporated into the pesto anyway.

Finishing With Lemon

My first test batches of pesto were good, but also somewhat flat and lifeless. It was clear I needed acid—not an ingredient one finds in a classic pesto—and the addition of lemon was perfect. A small amount of lemon juice adds brightness but is still fairly neutral, while lemon zest adds essential oils and a distinct trace of lemon flavor. I first tried this recipe with the zest of a whole lemon and that proved to be too strong. Zesting half a lemon yields the perfect amount, especially since you’re also using juice.

Serving the Pesto

The ramp pesto can be used in a variety of ways, including as a pasta sauce, mixed with cooked beans, slathered on a piece of fish prior to steaming or roasting, tossed with vegetables, with roasted chicken, or even as a spread on a sandwich. The important thing is to make sure the pesto has the correct consistency.

If using the pesto to sauce pasta, make sure to introduce it to the pasta off-heat so that you don’t accidentally cook off the freshness and vibrancy of the sauce. You’ll also want to thin the pesto using some reserved pasta cooking water; the starchy water helps transform the pesto into a beautiful green sauce which gracefully clings to the noodles, and if you use a shape like radiatori, it will seep into every nook and cranny.