Specialist Crafts · Article 11

Frozen Desserts

A reference article · 2,700 words · 40 cited sources · last reviewed October 2026 · fact-checked October 2026, 36 claims

Ice cream isn't frozen cream. It's four physical systems in one spoonful: a foam, an emulsion, a suspension of ice, and the syrupy unfrozen liquid holding them together. Every texture, and every defect, is one of those four going right or wrong.

Good ice cream is one of the most structurally complicated things a kitchen makes, and calling it “frozen cream” hides all of it. In a single spoonful there are four separate physical systems at once, and the craft is keeping all four in balance while the whole thing sits at a temperature where most foods would be a solid brick. Get the balance right and it stays soft, smooth, and scoopable. Get it wrong and it turns icy, grainy, greasy, or hard. This is how the four systems work and how the sugar math lets you tune them.

Four systems in one spoonful

Picture what’s actually in the spoon. First, a foam: air whipped in as discrete bubbles, often the single largest ingredient by volume, and the thing that separates ice cream from a frozen block. Second, an emulsion: milk fat broken into droplets around a micron across, which during freezing are deliberately made to partly clump together onto the air bubbles, building a fat network that holds the foam up. Third, a suspension: ice crystals and insoluble bits floating in the liquid. Fourth, a solution, the unfrozen serum, where sugars, proteins, and salts are dissolved in the water that has not frozen. That serum is the continuous phase that holds everything else together (Goff, 1997, 2002).

The useful mental model is a partly frozen foam: air and ice dispersed through a thick, concentrated syrup, laced with a network of partly clumped fat across the bubbles (Goff, n.d.-a). Change the size of the ice crystals, the amount of air, the strength of the fat network, or the thickness of the serum, and you change the eating experience. Nearly every recipe decision and every defect traces back to one of those four.

What each ingredient does

Milk fat brings richness, a slow melt, and the backbone of that fat network, but because it isn’t dissolved it barely affects the freezing point (Goff, n.d.-b; Bolliger et al., 2000). Milk solids-not-fat, everything in milk except fat and water, is mostly lactose and protein: the protein emulsifies, stabilizes air, and builds creamy body (Goff, n.d.-c; Goff, 1997). Its limit is sandiness, because too much lactose eventually crystallizes into a gritty texture, which caps usable milk solids at roughly 10 to 12% of the mix, a little higher or lower with the mix’s water content (Mullan, n.d.-a; Goff, n.d.-c). Sugars do two jobs that are worth separating in your head: they sweeten, and they depress the freezing point, which controls hardness. Egg yolk, in the custard style, was the original ice-cream emulsifier: its phospholipids and lipoproteins emulsify, and it adds protein richness (Goff, n.d.-a; Anton, 2013). Stabilizers like locust bean gum, guar, and carrageenan thicken the serum and hold free water so ice crystals grow more slowly in storage, at a dose of about 0.2 to 0.5% together with the emulsifier (Goff, n.d.-a, n.d.-c; Regand & Goff, 2003). Emulsifiers do the opposite of what the name suggests: they displace protein from the fat droplets to promote the controlled clumping that makes ice cream drier, stiffer, and slower to melt (Goff, n.d.-a; Bolliger et al., 2000).

The ice-cream column follows Goff’s formulation tables, where premium runs 12–15% fat and super-premium 15–18% (Goff, n.d.-c). Gelato varies by maker, so its column is one published artisan formulation rather than a standard (Giudici et al., 2021; Mullan, n.d.-b), and the sorbet figures follow Sipple and Young (2023).

The contrasts define the styles. Gelato usually carries less fat, whips in less air, and is served warmer and softer, somewhere around 5 to 12 °F (−11 to −15 °C) depending on the source (Mullan, n.d.-b; Giudici et al., 2021), and it is often described as tasting more intense. Sorbet removes dairy entirely, so sugar and stabilizer have to do all the structural work (Sipple & Young, 2023), which in practice makes it the hardest of the three to balance.

Why it stays soft: the freezing curve

Ice cream is scoopable because not all of its water is ever frozen: at serving temperature roughly a quarter of it is still liquid (Goff, n.d.-a). Dissolved sugars and salts lower the freezing point, and the effect is colligative, meaning it depends on the number of dissolved molecules, not what they are. That’s why molecular weight matters: a gram of dextrose (a small sugar) has about twice as many molecules as a gram of sucrose, so it depresses the freezing point about twice as hard (Goff, n.d.-b; Smith & Bradley, 1983).

The curve concentrates itself. As you cool below the initial freezing point of about 27°F (−2.5 to −3°C), some water freezes out as pure ice and leaves the solution, so the remaining serum gets more concentrated, which lowers its freezing point further, so the next bit of cooling freezes even less water (Goff, n.d.-b). The system chases its own tail. In practice, a standard mix is about 40 to 50% frozen at the draw point of 21 to 23°F (−5 to −6°C), roughly 70 to 80% frozen at 5°F (−15°C) where it is firm and scoopable, and never fully frozen even at deep storage temperatures (Goff, n.d.-a, n.d.-b). Serving hardness is largely how much of the water is frozen at that moment, so you engineer scoopability by engineering the sugar blend.

The sugar math: PAC and POD

This is the professional core, and it’s simpler than it looks. Give every sweetener two numbers, both scaled to sucrose at 100. POD is its sweetening power, how sweet it tastes. PAC is its anti-freezing power, how much it softens the frozen product. Sucrose scores 100 on both (Les Vergers Boiron, n.d.). The interesting sugars are the ones where the two numbers diverge.

The ratio of PAC to POD is a useful guide. Sucrose is one to one. A sugar with more PAC than POD, like dextrose at roughly two and a half to one, softens the product without making it sweeter. Low-DE glucose solids and maltodextrins are low on both scales, so swapping them in for sucrose adds body and firmness with little sweetness (Les Vergers Boiron, n.d.; Valrhona, 2022). That gives four clean moves. Too hard: swap some sucrose for dextrose, holding sweetness while raising the anti-freeze. Too soft: reverse it. Too sweet: use dextrose or a low-sweetness solid. Not sweet enough: add fructose and offset the extra softening with a low-PAC solid. Run one through. A gelato at 180 grams of sucrose per kilogram scoops too hard; replace 60 grams of that sucrose with 60 grams of dextrose and the sweetness drops by about a tenth (often welcome) while the sugars’ anti-freeze power climbs by roughly a quarter to nearly a third. The exact figure is 24 to 30%, depending on whether the dextrose is monohydrate or anhydrous, and a little less once the milk’s own lactose is counted (Goff, n.d.-b; Les Vergers Boiron, n.d.; Valrhona, 2022). The result scoops softer and cleaner without tasting sweeter. Sorbet runs at about 28 to 32% total solids, nearly all of it sugar (Sipple & Young, 2023), against 14 to 18% sugars in dairy ice cream (Goff, n.d.-c). With no fat or protein to keep it plastic, all of its scoopability has to come from that sugar, so it needs much more total PAC, and the fruit’s own sugar counts as part of the total.

Making it: from mix to hardened

Every production step exists to make ice crystals small and keep them small. Pasteurizing does double duty, making the mix safe while dissolving the sugars and hydrating the proteins and stabilizers. US rules for frozen-dessert mix set it as a time and a temperature together: at least 155°F (69°C) held for 30 minutes for the artisan batch method, or 175°F (80°C) for 25 seconds for high-throughput continuous (HTST) systems (U.S. Food and Drug Administration, n.d.-a; U.S. Department of Agriculture, n.d.; Goff, n.d.-c). Hitting the temperature without the hold is not pasteurizing. Homogenizing forces the hot mix through a tiny valve at high pressure, breaking the fat into droplets under about one micron across, which forms a stable emulsion and a large fat surface area for a smoother texture (Goff, n.d.-c). Aging the mix cold, at or below 41°F (5°C), for at least 4 hours and usually overnight lets the fat crystallize, the proteins and stabilizers fully hydrate, and the emulsifiers displace protein from the fat droplets, priming them for controlled clumping. The result is better whipping and a smoother body, and the extra fat structure also helps the finished ice cream resist melting (Goff, n.d.-c; Muse & Hartel, 2004).

Then comes churning, where a scraped-surface freezer does three things at once against a barrel wall chilled by refrigerant at roughly −8 to −26°F (−22 to −32°C): it freezes the mix, scrapes each thin frozen layer off into tiny crystals, and whips in air (Goff, n.d.-c; Warren, 2015). The rule is simple: the faster water freezes, the smaller the crystals, so a batch that freezes in minutes stays smooth while a slow freeze tends to turn icy, and even a well-built recipe cannot fully make up for it (Drewett & Hartel, 2007; Russell et al., 1999). A continuous freezer draws the soft product at about 21 to 23°F (−5 to −6°C), roughly soft-serve consistency, with about half its water frozen (American Institute of Chemical Engineers, 2019; Goff, n.d.-c); batch machines draw a little warmer. Hardening then rushes it to deep cold, ideally a blast freezer at −22 to −40°F (−30 to −40°C), to freeze most of the remaining water before the crystals can grow. It should then be stored at −13°F (−25°C) or colder where possible, the temperature below which Goff finds ice cream stable (Goff, n.d.-c); 0°F (−18°C), the usual retail and home-freezer setting, is the practical upper limit.

Overrun: how much air

Overrun is the percentage increase in volume from whipped-in air, so 100% overrun means the mix has doubled and half the final volume is air. It’s a real formulation lever, not an afterthought. More air makes ice cream lighter, softer, and less cold on the tongue, and it melts and collapses faster in the mouth; less air makes it denser, harder, colder-feeling, and richer (Sofjan & Hartel, 2004; Warren, 2015). This is a big part of why a cheap half-gallon feels fluffy and a super-premium pint feels dense.

The family

Every frozen dessert is a variation on which of the four systems it uses. Philadelphia-style ice cream skips the egg and relies on fat and milk solids for body; French or custard style is built on cooked crème anglaise for a dense, rich, slow-melting result. Gelato is the low-fat, low-air, warmer-served Italian style (Mullan, n.d.-b). Sorbet drops dairy for fruit, water, sugar, and stabilizer, and sherbet adds just a little milk back, 1 to 2% milk fat by the US standard, for creaminess and tang (U.S. Food and Drug Administration, n.d.-b). Granita skips the emulsion and the machine: a sweet liquid is frozen in a pan and stirred or scraped with a fork as it sets, so it ends in chunky, visible crystals (FoodCrumbles, 2022), though eastern Sicilian granita is made much smoother (Wikipedia, n.d.-a). Semifreddo and parfait glacé also skip churning, folding a pre-whipped meringue or pâte à bombe into whipped cream so the air is already in before it freezes, which keeps them soft enough to slice soon after unmolding (Lamb, 2021; Wikipedia, n.d.-c). Definitions of parfait vary: some include whipped cream, others use pâte à bombe alone. Kulfi concentrates milk by long simmering and freezes it without churning for a dense, slow-melting result (Wikipedia, n.d.-b). Soft-serve is served straight from the machine and never hardened, usually at a modest overrun of around 35 to 45% (Goff, n.d.-c; Taylor Company, 2025). At the extreme, liquid nitrogen at −320°F (−196°C) freezes so fast the crystals are minuscule (National Institute of Standards and Technology, n.d.; Liu et al., 2023). It is also an injury hazard: FDA warns that it can cause severe damage to skin and internal organs if touched or swallowed, so it is never added just before service and must have fully evaporated before anyone eats the dessert (U.S. Food and Drug Administration, 2018).

Defects

Almost every defect is either crystals grown too big or the fat, air, and stabilizer balance gone wrong, and the cold chain matters as much as the recipe (Goff, n.d.-c).

Iciness and sandiness follow Goff’s defect list, where fluctuating storage temperature is named the most likely cause of a coarse, icy texture (Goff, n.d.-c; Drewett & Hartel, 2007). Stabilizers slow recrystallization rather than stop it (Regand & Goff, 2002; Hagiwara & Hartel, 1996). Over-whipping churns the fat toward butter (Goff, n.d.-c). Colder draws drive more fat destabilization, and within normal ranges that extra structure actually reads as less greasy, not more (Amador et al., 2017). The two hardness rows are the PAC logic from the sugar section applied in reverse (Mullan, n.d.-c).

The idea in one paragraph

A frozen dessert is four systems held in balance: air whipped in as a foam, milk fat as a fine emulsion that partly clumps to build structure, ice as a suspension of crystals kept small, and a concentrated unfrozen serum that is the real continuous phase. It stays scoopable because dissolved sugar keeps part of the water liquid, and because ice forming makes the leftover syrup ever more concentrated and harder to freeze. You tune it with the PAC and POD of your sugar blend, adjusting sweetness and hardness largely independently, and you protect it by freezing fast, aging the mix, and holding a steady cold chain, since fluctuating storage temperatures are the most likely cause of icy texture in an otherwise good ice cream (Goff, n.d.-c).