#churnt

Most ice cream recipe books written for general audiences are simplified from the formulae used by the ice cream makers that write those books. One reason for this is that sometimes the recipes (or ingredients) are considered too complex for home cooks; another is that ice cream shops often do not want to give away their proprietary recipes. In any case, the implication is that while most ice cream shops use stabilizers in their recipes, most ice cream recipes do not.

I have only scratched the surface of stabilizer use—but I have found it challenging to find reliable information on stabilizers, so wanted to start putting what I’ve learned in one place. Here is a start.

How do stabilizers work?

Ice cream is a mixture of water (liquid and ice), fat, sugar, air, and often other solids like proteins and fiber. All these things exist in dynamic equilibrium, meaning that—particularly when you take ice cream out of the freezer—some of the water is refreezing while some of the ice melts.

Stabilizers (also called hydrocolloids) help make this equilibrium less dynamic, by creating a structure that helps keep everything in place. This structure of small particles exist in suspension in water, acting almost as roots holding soil more firmly in place.

What do stabilizers do for ice cream?

In the absence of stabilizers, ice crystals melting and re-freezing rapidly degrades ice cream’s quality. Have you tasted Häagen-Dazs after it has been out on the counter for too long and then refrozen? That’s what I’m talking about. It’s a bad scene.

One solution is just to eat your ice cream all in one sitting. But that isn’t always practical. Stabilizers come in handy when, like me, you prefer smaller ice cream servings.

When an ice cream is properly stabilized, the result is that everything stays where it is supposed to be, even as the ice cream mixture’s temperature fluctuates. This helps slow ice crystal growth, which is important because big ice crystals—very intuitively—are typically what make ice cream taste grainy rather than smooth. The ice cream mixture (particularly when it is melted or unfrozen) will also be thicker, more viscous, because stabilizers build structure by locking water into place.

What are stabilizers?

Not all stabilizers are unfamiliar—egg yolks function as stabilizers in custard-base ice creams, and cornstarch is used as a stabilizer in puddings, pie, and gravy. Gelatin and dry milk powder are also both stabilizers. Gums are the most “contentious”—but also the most powerful—stabilizers for ice cream. Gums that are commonly used as ice cream stabilizers include locust (or carob) bean gum, guar gum, carrageenan, and xanthan gum—though there are others. Stabilizer proponents are quick to note that these gums are nearly all plant-derived, as opposed to… mysteriously synthesized or genetically modified in a secret underground lair.

How do I use stabilizers to make better ice cream?

Glad you asked. Each stabilizer works differently. Some need to be heated to a certain temperature in order to be ‘activated’; others (like carrageenan) interact in special ways with dairy; stabilizers vary in strength; carrageenan has several different forms (descriptively called kappa, iota, and lambda) with even *more* different properties; some stabilizers are cheap and easy to find, while others must be special-ordered and can be quite expensive; and complicating matters further still is that stabilizers interact with each other in different ways, such that it is often a good idea to mix them together.

What I would like to have—but have not seen—is a table that attempts to summarize the various parameters for each stabilizer (e.g., heating requirements, ice cream mix concentration range, complementarity with other stabilizers, other chemical considerations, cost/accessibility). Here is a link to the [freely available] readings I have found to date. I’ve also linked to a few good summary blog posts below. Dana Cree’s Hello My Name is Ice Cream is the book that provides the most useful insight into how to incorporate stabilizers into your ice cream, and I have found myself using it as my go-to stabilizer reference when designing new recipes.

Underbelly NYC on stabilizers

Ice Cream Science on stabilizers

Some relevant thoughts from Michael Laiskonis

An example (pistachio sorbet), from Modern Cuisine

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But now he (with contributions from his team at Superiority Burger and many others who have helped along the way, to all of whom he gives liberal credit for the restaurant’s success) has published the restaurant’s eponymous recipe compendium, the aptly named “Superiority Burger Cookbook: The Vegetarian Hamburger is Now Delicious”. I am only a little sad that it doesn’t include his insane focaccia and bean soup recipes but I won’t dwell on this because the book is a treasure trove of insights, and he doesn’t appear to have held back on sharing the secrets of what makes the restaurant’s food sing. He certainly doesn’t with the ice cream.

This past week I got to work. The gelato recipes all have the same structure: mix the dairy and sugars, heat to a simmer (180 degrees F), hold the mixture there for thirty minutes while you infuse whatever the flavor is, then add salt, strain, cool, and let sit overnight before churning. Likewise, the sorbet recipes each use a consistent structure: a mixture of a pre-made syrup (water, sugar/sucrose, and dextrose) and a fruit puree (or chocolate). A pleasant surprise (but also not a surprise, given how good the ice cream is) is also that Dana Cree, the author of the best home ice cream cookbook written to date and co-owner of Chicago’s Pretty Cool Ice Cream, once upon a time helped design these base recipes with Brooks via late-night text message. But I digress.

The results are revelatory. I made chocolate sorbet (which is generally superior to chocolate ice cream if you love chocolate -- don’t @ me) and used the Superiority gelato base to make a black cardamom ice cream. The reason these recipes blew me away is that the results stay astoundingly soft in the freezer, with no stabilizers. The surprising yet subtle flavors (”cone” gelato and cherry vanilla sorbet, on my most recent visit) and impossibly soft texture right out of the freezer are what sets Superiority Burger’s ice creams apart from the rest. 

A big part of the reason for that softness is the process. By heating the gelato base above , you denature proteins in the dairy, which allows them to bind with more water, functioning like a stabilizer. This allows you to avoid worrying about stabilizers in the first place, and to avoid using eggs, which can alter the flavor of the base (and which, especially among Superiority Burger patrons, many people don’t eat). Keeping the mix at a relatively low temperature reduces the risk of scalding the milk, but is more than high enough to denature those proteins (they start denaturing around 70 degrees C; 180 degrees F is about 80 degrees C). Holding the temperature there for thirty minutes requires a thermometer, a whisk, a watchful eye, and steady, low burner heat, but the results are well-worth it if you have the time and inclination (just try not to forget to halve the black cardamom if you’re halving the rest of the ingredients, or it might taste a little too strong). 

I haven’t done a more detailed analysis of these recipes to see where they sit in terms of water/sugar/fat/solids ratios and now that I’m thinking about it, I should also check my freezer temperature (I moved recently) , but both the sorbet and the ice cream might be a little *too* soft, which could require some adjustments to refine for my home set-up and personal preference -- in other words, some trial and error. Delicious, delicious trial and error. 

At some point, the same friend warned that I should use the paste sooner than later, lest it go bad. I am sure it tastes best fresher but given the near-unlimited shelf-life of peanut butter I was unconcerned. The night before a dinner party in March, I decided it was time, procured the necessary ingredients, and set everything out on the counter.

Opening the jar, my heart sank—a strange, alien substance was coating the surface of the pistachio paste, in the form of countless tiny pale green globules (I am so sorry, for both our sakes, that I did not take a photo). My plans were ruined.

Or were they? After Google proved uncharacteristically unhelpful, I decided to risk a bad stomach ache and tasted a spoonful of the globules to see if they might just be congealed oil. Bingo—back in business. It is a good thing, too, because I never would have heard the end of it.

Max’s pistachio gelato recipe is straight-forward and he is very good at making ice cream so I am sure it is also delicious. At the other end of the spectrum, I am also sure that the dizzyingly complex pistachio gelato recipe from Modernist Cuisine (which is technically a sorbet) is delicious, but I have neither Polysorbate 80 nor Gylcerol monostearate in my pantry so I figured I would save that for another, more ambitious day.

I prefer a middle ground, somewhere between a classic French-style ice cream and molecular gastronomy, which is hard to find online. Dana Cree’s exceptional Hello, My Name Is Ice Cream sets the standard for that middle ground, but we will have to wait for her next book to get a pistachio recipe (although I did use a couple of her tricks).

So I wrote my own. I wanted a low-sweetness, [relatively] high-salt recipe to let the pistachio paste take center stage (another inspiration: a distant summer memory of a salty pistachio milkshake from the Momofuku Milk Bar). Here’s where I landed:

When you let the ice cream soften for a little too long before scooping it

Pistachio ice cream

Makes about a quart of rich, savory-sweet ice cream

690g whole milk

230g pistachio paste

115g sugar

3 egg yolks

54g skim milk powder

34g glucose powder

6g tapioca starch

5g salt

2g stabilizer (I used a 3:1 mix of guar and xanthan gums)

Mix tapioca starch with 10g milk into a slurry and set aside

Set aside 200g milk and refrigerate

Prepare an ice bath

Mix remainder of milk, egg yolks, sugar, and glucose in saucepan over medium heat and whisk constantly until mixture reaches 160 degrees

Pour resulting custard into a metal bowl and mix in tapioca slurry (I use an immersion blender)

Add pistachio paste and refrigerated milk to the bowl and mix well (you should definitely own an immersion blender), placing the bowl into the ice bath

Combine salt and stabilizer and add to the bowl, mixing well to incorporate evenly and avoid clumping

Once mixture is cool to the touch, refrigerate for eight hours or overnight 

Churn as you see fit, and allow to firm up for a few more hours

Serve, perhaps in an array of mismatched ice cream bowls? 

This is what ugli fruit looks like

This was an opportunity to consider an upgrade—I’ve been wanting the option of churning multiple flavors in sequence, so I poked around to see if any self-refrigerating machines were in my price range. I found the Sweethome’s ice cream maker guide particularly helpful, and ended up ordering the Whynter ICM-15LS. Self-refrigerating machines take up substantially more space in the cupboard, but less space in the freezer than the common pre-freeze canister units, which I have used since my first ice cream machine—which relied on ice and salt—had a motor failure during a particularly busy ice cream–making week. 

I chose the Whynter over the substantially more expensive Lello 4080 Musso Lussino, which affords the One Percent of home ice cream makers shorter freeze times (in large part because it does not have a removable ice cream canister) and thus smaller ice crystals and smoother ice cream. I chose the Whynter machine, however, [mostly because I could not justify the cost, but also] because with a removable canister it is much easier to clean.

This is what my new ice cream machine looks like

Being able to make repeat batches is a game changer, but it’s not quite back-to-back, because it’s important to pre-freeze the canister for about 15 minutes before adding the ice cream mix, to reduce freezing time. Thanks to Ruben at Ice Cream Science for confirming that this was a good idea (in this post, which is also a great, comprehensive primer on ice cream science basics)—because the manufacturer provides no useful guidance.

The new Whynter machine does not reduce freezing time relative to a Cuisinart with a pre-frozen canister—among the biggest determinants of ice crystal size—so the ice cream’s quality is not an improvement. Indeed, in a couple of the batches I have made so far, particularly without letting the machine cool down in advance, the final product seems icier than in a Cuisinart. Part of this could be attributed to what seems like too wide a gap between the canister walls and the mixing paddle (aka ‘dasher’). Using stabilizers has helped reduce ice crystal formation, but the machine’s motor also struggles a bit with thicker mixes.

Those cautions aside, this new machine has been a lot of fun and I am reveling in the newfound flexibility it provides. One of my first experiments was to compare three different chocolate ice cream mixes, each a slight variation on Michael Laiskonis’ chocolate ice cream #1. The stabilizer concentration was too high in the two stabilized mixes I churned, likely because I was using a different blend than Chef Laiskonis would (I made one batch with three parts guar to one xanthan gum; and another with a 50/50 blend of guar gum and iota carrageenan). This yields ice cream that melts into pudding and is gummy, almost chewy—but both batches still taste fantastic. The unstabilized batch has chocolate whisky instead, which without stabilizers resulted in an icier batch—though one whose taste both my roommates preferred. Initially, they also preferred the texture of the slightly icy, unstabilized ice cream to the two over-stabilized batches.

A post shared by Churning Man (@churning_man) on Apr 22, 2017 at 5:01am PDT

The other trio of ice creams I made were on an end-of-Winter whim, when ugli fruit and bergamot happened to be available at the nearby grocery store. I made sorbets with both and paired them with a basic vanilla. I can’t say I recommend bergamot sorbet, but the ugli fruit turned out nicely. Citrus sorbets are tricky because the juice lacks some body compared to more fibrous fruits—ice cream or sherbet might usually be a better move, especially to maximize creamsicle vibes. Until next time though, the recipe I landed on is included below. 

A post shared by Churning Man (@churning_man) on Apr 22, 2017 at 6:28pm PDT

Ugli fruit sorbet 

Makes ~1000g, or a little more than a quart

700g ugli fruit (measured at 10.3 brix)

100g sucrose

150g light corn syrup

5g salt

2g xanthan gum (or other stabilizer; optional)

40g vodka (40 percent alcohol)

All recipes credit to Chef Michael Laiskonis

Chocolate ice cream 1

Makes about two quarts

38g nonfat dry milk powder

80g sucrose (1)

1650g whole milk

11g ice cream stabilizer [e.g. Cremodan 30, but you could use another blend]

90g sucrose (2)

125g invert sugar

492g dark chocolate couverture (66%), chopped

Combine dry milk and first measurement of sucrose (1).  Place milk in a heavy saucepan, whisk in dry milk mixture, and begin to cook over medium heat.

Meanwhile, combine the second measurement of sucrose (2) and stabilizer. Whisk this sugar and stabilizer mixture into the milk and heat to 85°C/185°F.

Gradually incorporate hot milk into chocolate and invert sugar; homogenize well with an immersion blender.  Chill in an ice water bath. Allow mixture to mature at least 12 hours.

Process in batch freezer; extract the mix at -5˚C/23˚F. Alternatively, transfer to PacoJet canisters and freeze; process as needed.

Chocolate ice cream 2

Makes about two quarts

90g nonfat dry milk powder

80g sucrose (1)

1010g whole milk

480g heavy cream (35% fat)

10g ice cream stabilizer

80g glucose powder

200g sucrose (2)

60g cocoa powder (Dutch-process, 20-22% fat)

Combine dry milk and first measurement of sucrose (1).  Place milk and cream into a heavy saucepan, whisk in dry milk mixture, and begin to cook over medium heat.

Meanwhile, combine the glucose powder, second measurement of sucrose (2), and stabilizer.  Whisk this sugar and stabilizer mixture into the milk and heat to 85°C/185°F.

Incorporate the cocoa powder into the hot milk mixture; homogenize well with an immersion blender.  Chill in an ice water bath. Allow mixture to mature at least 12 hours.

Process in batch freezer; extract the mix at -5˚C/23˚F. Alternatively, transfer to PacoJet canisters and freeze; process as needed.

Raspberry ice cream

Makes about three quarts

750g whole milk

188g heavy cream (35% fat)

150g nonfat dry milk

225g sucrose

75g glucose powder

100 invert sugar

13g ice cream stabilizer

1000g raspberry purée [this and the coconut purée in the recipe below refer to specialized professional-grade products like those sold by Boiron]

Place milk and cream in a saucepan. Whisk in dry milk to rehydrate and add the sucrose, glucose, invert sugar, and stabilizer. Heat to 85°C/185°F.

Remove from heat, whisk in the purée, and homogenize with an immersion blender. Chill in an ice water bath. Allow the mix to mature at least 12 hours.

Process in batch freezer; extract the mix at -5˚C/23˚F. Alternatively, transfer to PacoJet canisters and freeze; process as needed.

Raspberry sorbet

Makes about two quarts

55g sucrose (1)

4g sorbet stabilizer [e.g. this one from Chef Rubber]

430g water

165g sucrose (2)

110g glucose powder

36g dextrose

1000g raspberry purée

Combine first measurement of sucrose (1) and stabilizer.

Heat water to 50˚C/120˚F.  Whisk in stabilizer mixture, then remaining sucrose (2), glucose, and dextrose; bring to a boil for about 30 seconds.  Remove from heat and chill; allow syrup to mature for at least 4 hours.

Combine purée and syrup and process in batch freezer; extract the mix at -5˚C/23˚F. Alternatively, transfer to PacoJet canisters and freeze; process as needed.

Coconut sorbet

Makes about three insanely silky quarts of frozen perfection

40g sucrose (1)

6g ice cream stabilizer

730g water

300g sucrose (2)

150g glucose powder

1000g coconut purée

Combine first measurement of sucrose (1) and stabilizer.

Heat water to 50˚C/120˚F.  Whisk in stabilizer mixture, then remaining sucrose (2) and glucose, bring to a boil for about 30 seconds.  Remove from heat and chill; allow syrup to mature for at least 4 hours.

While staring indecisively at a full ice cream case, I almost always ask ice cream scoopers what their favorite flavors are. The gentleman working in Fell + Cole on this day said that rum raisin was his favorite, but that tiramisu was the best *today*. Neither are flavors that would typically speak to me (though tiramisu is among my favorite desserts), but I couldn’t help but ask why today was different from any other. 

The answer, not surprisingly, was that it was freshly churned--so it was extra soft, and extra smooth. This is typical in the best gelaterias, which serve gelato with extraordinary consistency because they make it fresh every day, but less so in your everyday ice cream shop. 

Why does freshness make a difference? Because one of the primary determinants of ice cream texture is the size of the ice crystals suspended in the ice cream mixture. One of the most magical things about ice cream is that it is composed simultaneously of solid, liquid, and gas elements (technically, because air is suspended in liquid, a ice cream is a “foam”). When ice cream has an icy mouthfeel, it’s because there are literally larger ice crystals in the mixture. This happens when ice cream has been thawed and refrozen repeatedly, but it also happens when ice cream is put in a freezer from the ice cream machine for the first time--because the machine does not *completely* freeze the ice cream. This “second” freezing process firms up the ice cream to the consistency we know and love, but not without, inescapably, making the ice cream less smooth (this is the primary argument for increasingly common “made to order” liquid nitrogen ice cream, like the nutella cone pictured below). 

A photo posted by Churning Man (@churning_man) on Sep 8, 2016 at 5:26am PDT

To compensate for a lack of same-day freshness, an ice cream maker can design her recipes to ensure continued softness, which is particularly important for wholesale frozen desserts that are sold in grocery stores. Stabilizers like xantham gum, carageenan, and guar gum can help preserve softness over time, as can alcohol, salt, or even caramel (though I have not been able to figure out why). 

But once larger ice crystals are formed, there’s no going back--so remember to ask your local ice cream scooper what’s fresh the next time you’re at the counter. 

Morgenstern’s “Heavy Hitters” series had caught my eye, a weekly special creation resulting from a new collaboration each week during August. The week I went, the collaboration was “Molto Mario’s Modena Creamsicle”, a Mario Batali-inspired sour cherry and mascarpone joint venture.

The result certainly deserved full marks for presentation. And the Sicilian pistachios gracing the dark side of the silky mascarpone were a surprising standout. The sour cherry sorbet was a little icy, but the marriage of both flavors was excellent. As the kind people at Superiority Burger know, I am a sucker for great ice cream + sorbet combinations. The cone is, as you can see, a novelty -- though I actually prefer cake cones to sugar cones most of the time (more ice cream absorption), so I didn’t really mind. I would almost always prefer waffle though, and if I’m being honest the world needs more cone innovation.

Standing in line, I made a new friend who had a cool, non-functioning watch, and talked to a stranger who was hoping Morgenstern’s lived up to her experience at Portland’s Salt and Straw. A tall order to fill, but I’m guessing she left satisfied (and I reassured her that she would).

The real MVP that night, though--and I still think about this, even six months later--was a single tasting spoon of black raspberry ice cream. Something about raspberry ice cream really works for me in general, but this one was intensely smooth, purely flavored (Morgenstern’s does not use eggs in their base, which allows delicate fruit flavors to shine), and perfectly balanced.

This black raspberry spoke to me, so much so that I returned to Morgenstern’s the following morning (they open early, at 8am) to eat a scoop for breakfast (which, apparently, is a good idea). The kind, sympathetic woman behind the counter searched high and low but there was none left--a tragedy, but there’s always next year. She did, however, offer me another tasting spoon of the new “Heavy Hitters” flavor, a lemon verbena sorbet with plum jam from Chef Marco Canora, which made the trip worthwhile.

When summer comes, I recommend you go and get whatever Morgenstern’s cooks up next--ideally in the morning, before the line starts to form. In the meantime, go whenever the craving strikes and savor the fact that ice cream doesn’t melt when it’s freezing outside. Just ask this guy (source):