Starting with our guide to blanching and peeling pistachios, followed by a steady stream of recipes for everything from homemade pistachio paste and pistachio cake to pistachio whipped cream and a pistachio frangipane tart, Serious Eats has been pistachio central for a few weeks now.
But in truth, all of those articles and recipes were a byproduct of my quest for this, the best pistachio ice cream—made from fresh pistachios, not pistachio paste.
Why not paste? To start with, homemade pistachio paste is simply too coarse. If stirred into the base, it would produce an ice cream with an objectionably gritty texture. But if strained out, it would take a substantial portion of the flavorful dairy along with it, since the finely ground nuts are so absorbent.
While commercial pastes are smooth and silky enough to be incorporated into an ice cream base without straining, their quality and freshness may not be apparent until you've bought a jar to taste for yourself. Often, these pastes are quite oxidized, with a muddy brown color and a flavor that's less than fresh.
At least in my neck of the woods, pistachio paste is exclusively a mail-order item, while good quality pistachios are easy to find from local Greek and Indian grocery stores, as well as in specialty food shops and the bulk aisle of a particularly well-stocked supermarket.
Which brings us back to the idea of an ice cream made from whole pistachios, whose flavor and freshness are easy to assess when buying them raw in bulk. Good raw pistachios will look plump and green beneath their skins; they'll smell aromatic and fresh, with a firm (not crumbly) consistency when gently squeezed, and a rich pistachio flavor even prior to peeling and toasting.
Great pistachios will almost always be less expensive than an equally great pistachio paste, as its cost reflects the labor-intensive manufacturing process needed to blanch, peel, toast, and mill the nuts.
Of course, when buying whole, fresh pistachios, most of those chores fall to me, and I can't lie—peeling and blanching pistachios can be a real drag.
Fortunately, it's easy work that can be done while watching a movie or talking with a friend. Once you see (and smell!) the mountain of musty skins standing to the side of a gleaming pile of pistachios, you'll appreciate the necessity of this step, and the clarity of flavor it delivers. Plus, it gives me time to pull off a batch of quick toasted sugar, which pairs particularly well with pistachios.
After blanching and peeling, the pistachios will have a bright, fresh flavor that works nicely in certain applications, such as homemade pistachio paste, an ingredient that will often go on to be used in baked goods, where its flavor will develop a toasty quality in the oven.
But in an ice cream or gelato served at temperatures below freezing, the flavor of raw pistachios will seem muted, translating into something vegetal and dull, like wet lawn clippings. So in recipes like this one, pistachios benefit from being slowly toasted at low heat, both to drive off any water absorbed during the blanching process and to develop some nutty complexity.
I do this by lightly coating the blanched and peeled pistachios with a little oil, preferably pistachio oil* since that gives me a chance to layer in more flavor, but neutral oils will get the job done.
*Look for pistachio oil with other salad oils on supermarket shelves, or pick up a bottle online. It's the key ingredient in our super easy pistachio cake, which will blow your mind when served warm with a scoop of pistachio ice cream on top.)
I spread the lightly oiled pistachios out on a parchment-lined half sheet pan, and toast them at 200°F until they're firm and dry to the touch, with a faintly nutty aroma, and hints of pale gold and olive starting to develop amid the brighter green.
This can take anywhere from three to four hours, depending on the accuracy of the temperature dial on a given oven, as well as how much water the pistachios absorbed during the blanching process (a variable that is, in turn, influenced by both freshness and technique).
It takes time to develop a pistachio flavor that's bold and complex, so don't try to rush this step. When toasted at higher temperatures for a shorter period of time, the pistachios take on a pronounced roasted flavor that's dusty, dull, and generic, like stale white bread that's been toasted too long.
So please, after buying expensive, good pistachios, and all the work of blanching and peeling them, don't throw it all away by neglecting the pistachios while they're in the oven. Stir them often, to help them toast evenly, and to keep yourself abreast of their changes in texture and color. Don't keep toasting until they're baked to a crisp and dull brown; stop when they're firm, dry, and just a little golden, although still quite green all around.
When the toasted pistachios are cool enough to handle, give them a rough chop and combine them with milk and cream in a 3-quart saucier. If you're working with American pistachios, or Sicilian pistachios that are slightly past their prime but too good to toss, add a small sprig of rosemary and a thin strip of lime or orange zest into the pot. These aromatics contain a compound called alpha-Pinene, which is found in toasted pistachios. With subtle use, they can supplement the aromas that may be lacking in mild pistachios, and help the flavor pop.
With or without these "bonus" ingredients, bring the dairy to a simmer over medium heat, stirring frequently until the first bubbles appear and the cream begins to foam. Immediately take the saucier off heat, cover tightly, and set aside until cool to the touch. I'll typically refrigerate the pistachio-milk between 12 to 36 hours. For me, 24 hours is the sweet spot for both convenience and flavor, but you've got plenty of wiggle room either way.
This long-term, hot-to-cold infusion will pull out an incredibly complex pistachio flavor, so much so that you'll be able to strain the pistachios out altogether.
But don't feel like anything's going to waste! Because of that gentle toasting, those milk-soaked pistachios still have plenty of flavor left for making homemade pistachio paste, an ingredient that can go on to be used in recipes like triple-pistachio buns, pistachio whipped cream, and our pistachio frangipane tart! There are plenty of options, so don't fret about not using those milk-soaked pistachios here.
When the saucier is comfortable to touch, warm but not hot, it can be used to make the custard, without any pause to wash-up. Just add in the sugar (preferably toasted), egg yolks, and salt, then whisk to combine. When smooth, whisk in the warm pistachio milk, as well.
I start the custard off over medium-low heat, stirring and scraping constantly with a flexible, heat-resistant spatula until it feels warm to the touch. After that, I can safely increase the heat to medium in order to cook the custard through, stirring and scraping all the while. Extreme precision isn't required for a step like this; I usually cook the custard until I can see visible wisps of steam rising up, but 165°F is a safe target to aim for.
After straining, I like to add a splash of alcohol to both improve the consistency of the finished ice cream, and to serve as an aromatic. Many different types of spirits and liqueurs will work well, so let the options in your liqueur cabinet guide you, and don't feel compelled to spring for a bottle of something new.
Spirits with a stone fruit or citrus profile can mesh well with pistachio, like Maraschino or Cointreau, or you can opt for those with an overtly nutty profile, like Pistacchino or even Amaretto. I've also found that amaros work particularly well, as their herbaceous profile adds a nice sense of freshness when diluted into the base.
I've been happy with Cardamaro in that role, but Cynar is a standout option that works wonders for the flavor of pistachio.
If your liquor cabinet doesn't seem to have any good options, or if you abstain from alcohol, there's no need to add a thing. The ice cream may be a little harder straight from the freezer, and a touch less aromatic, but these aren't make or break details.
Another optional step for this ice cream—color correction. Purists may revolt at the notion of food coloring, but between the yellow-gold of the toasted nuts and rich orange color of egg yolks, this ice cream can't help but have a naturally beige to yellow hue.
It's a well established fact that we eat with our eyes, and I'm not above using a touch of food coloring. The idea isn't to dye the ice cream an artificial green, but to use a hint of blue (!) gel paste to neutralize the yellow tones that pistachios develop with toasting, so that the ice cream's color will better telegraph its flavor at a glance.
Skip this step if you like, or embrace the science of color correction with a light blue gel paste from a brand like Americolor. Color correction requires so little blue food coloring, you won't even use half a drop, just whatever little wisp you can smudge onto the edge of a whisk or spatula.
Be patient, and stir more than you think is necessary, to ensure the blue dye has fully dissolved into the base. Or skip this step altogether, and embrace the khaki vibe of the ice cream au naturel.
The final step before churning is to chill the ice cream base to about 39°F (4°C), which can be done passively in the fridge or proactively over an ice water bath. (See our guide to the best ice cream machines for more information on which models we like to use.)
Churn the chilled base until the ice cream is fluffy, light, and wonderfully thick, with nothing runny or milkshake-like about it. Enjoy as soft-serve, or transfer to a chilled non-reactive container with a chilled flexible spatula, cover tightly, and freeze until firm enough to scoop.
Despite all the time and effort involved (which ranks high, even for me), this is absolutely one of my favorite ice creams, as smooth and aromatic as they come, with a true pistachio flavor that shines through in every bite.
It's wonderful when served all on its own, or as an à la mode component to the aforementioned pistachio cake or tart. It's also a bang-up combination with our no-churn blueberry ice cream, as its rich and nutty flavors are offset by the floral/fruity notes so well.
And if you were to decide on a batch of homemade waffle cones, be sure to use that roasted pistachio oil in the batter!