The Subtle Secrets to Making the Best Ice Cream Mix-Ins

If you're like my mom, for whom a pint of Ben & Jerry's is happily dinner, ice cream barely counts as ice cream until you put "stuff" in it. That's why we're a New York Super Fudge Chunk family; I challenge you to find an ice cream with a higher chunky-stuff index in the grocery store.

So when I make ice cream for mom, adding lots of stuff is at the top of the priority list. That's one of the reasons why I developed this rocky road recipe, which is 30% chunk by volume. It's also why I want to set a few things straight today. Sure, adding mix-ins to homemade ice cream seems as simple as dump-and-stir, but a few bench notes will turn a merely chunky ice cream into a fantastic one.

Curious about the best chocolate chips for ice cream and how to make those pretty swirls? Welcome to the ultimate guide to mix-ins.

How Much Junk You Want in That Trunk?

Ice cream recipes always include amounts of chunky stuff to put in your churn, but rarely do they tell you just how chunky the resulting ice cream will be. Here are the guidelines I use for nuts, candy, and chocolate per quart of ice cream:

• 2 ounces = about 1/2 cup = noticeable chunkiness but with chunk-free bites
• 4 ounces = about 1 cup = fully loaded train to chunkytown

Using lighter chunks like marshmallows? The volume measurements above are good guides. As for swirls of fudge, caramel, or jam, 3/4 to 1 cup of gooey stuff per quart is your sweet spot for swirls in every spoonful without overwhelming your ice cream base.

Sieve Those Chunks

Chopped candy, nuts, and chocolate rarely come out in perfectly even sizes. This is good! A variety of sizes adds interest to the texture of your ice cream. But you know those tiny little specks of dust you get as you chop? All they'll add to your ice cream is grittiness. Fortunately, the solution is easy—put all your chunks in a fine mesh sieve and shake it until the dust falls through. What stays behind is large enough to stand out in your ice cream.

Then Chill Them Down

Once you've sieved your chunks, give them a chill in your freezer while your ice cream churns. This is especially true if you've just toasted nuts for deeper nutty flavor. Why the fuss? Because ice cream doesn't like changes in temperature, and adding warm or room temperature nuts to freshly churned ice cream will melt pockets of the ice cream before the base can fully harden.

It's a subtle difference, but a noticeable one. Ice creams full of chunks take longer to set, and pre-chilling chunks makes for faster hardening times, which in turn means slightly smoother, creamier ice cream when it fully freezes.

The Best Way to Make Chocolate Chips

Let's take a minute to talk about pieces of chocolate in ice cream. Namely, their problems.

As temperature drops, chocolate turns brittle, taking on a chalky quality that melts slowly in your mouth. That's why I tend to avoid adding large chunks of chocolate to my ice cream, and when I do, it's usually milk chocolate, which, thanks to its higher amounts of sugar and milk solids, stays softer even when fully frozen. But even then, the chunks just aren't ideal.

You might consider chocolate chips instead. After all, they're the right size and melt in your mouth well enough when baked into cookies. But the very thing that makes chips so good in cookies makes them a bad choice for ice cream: They contain stabilizers to help them keep their shape while melting, which means they make frozen chips as stubborn to melt as plain 'ol frozen chocolate, just with a waxiness replacing chocolate's typical grit.

So here are my two moves. If I want an even distribution of tiny chocolate shards in my ice cream, like in this boozy burnt caramel, I'll shave the chocolate with a vegetable peeler to form light, fluffy flakes that melt quickly in your mouth.

If I want chips, I'll take a tip from the Italians and make straciatella. Straciatella is Italian for "shreds," and in ice cream terms it means a drizzle of warm chocolate swirled into churning ice cream that sets into snappy ribbons, which then break into chips. With a mix of whisper-thin threads and thicker clumps that naturally form in the churn, straciatella offers the best variety of textures in a single scoop. Better yet, with one simple trick, the chocolate itself melts in your mouth, velvety and soft rather than unpleasantly hard and crunchy, as often happens with frozen chocolate.

That trick? Adding a teensy bit of neutral-flavored oil to the chocolate as it's melting (I use a teaspoon for every two ounces of chocolate), which, when the chocolate refreezes, lowers its melting point so the chips melt faster and smoother in your mouth. You could use cream or butter to the same effect, but oil delivers the cleanest texture while preserving the chocolate's intense bitterness. You'll want to drizzle the chocolate in during the last minute or two of churning. Add it earlier and the "chips" may streak and start blending into the ice cream for a murky brown effect.

How to Swirl

Want to add a pretty swirl of jam, caramel, or fudge to your ice cream? Great. But don't think swirl. Think layer.

Start drizzling fudge or caramel into your churning ice cream and you won't make a swirl; you'll get a muddy streak. To keep swirls clear and unmuddied, add them once the ice cream is already churned. By layering ice cream with its swirl in a long, wide container like a loaf pan (the best tool for storing ice cream in your freezer!), you create striations that, when scooped, formed nice swirls. Here's how it's done.

Start with a bed of ice cream along the bottom.

Then gently spoon in your filling, dolloping it on top rather than spreading it around with a spoon. I'm using room temperature strawberry jam that I stirred vigorously until it loosened up.

Add more ice cream...

...and more filling.

When you get to your top layer, give a couple swirly flourishes with your spoon.

The only challenge here is to work as quickly as you can. Freshly churned ice cream melts fast, and every second before you can get it into the freezer means an icier final product. So once you start swirling, don't pause, don't wipe up any spills, don't stop to Instagram it, until that ice cream is safely in the freezer.

You can take all the pretty pictures you want once that sucker's firmed up.