The legal definition
In the U.S., ice cream is a legal term. Gelato is not.
The federal frozen dessert standards sit in 21 CFR part 135. That part has sections only for ice cream and frozen custard (135.110), goat’s milk ice cream (135.115), mellorine (135.130), sherbet (135.140) and water ices (135.160). There is no U.S. standard of identity for gelato.
The ice cream rule is specific. 21 CFR 135.110(a)(2) says: “Ice cream contains not less than 1.6 pounds of total solids to the gallon, and weighs not less than 4.5 pounds to the gallon. Ice cream contains not less than 10 percent milkfat, nor less than 10 percent nonfat milk solids”.
Two things follow from that.
- A frozen dessert with less than 10% milkfat cannot be sold as ice cream in the U.S. That is our reading of the rule. We found no FDA text on what such a product must be called. The floor drops to 8% of the whole when bulky flavors such as chocolate, fruit or nuts are added.
- Because gelato has no standard, a label that says gelato tells you the style the maker is aiming for, not a fixed recipe.
Eggs follow the same pattern. Ice cream holds less than 1.4% egg yolk solids. For gelato, egg yolk is not set by any standard we found.
Fat and solids
Gelato vs ice cream starts with fat, and every source we use agrees that gelato has less.
- SIGEP World, the Italian gelato trade fair, gives gelato about 4 to 8% fat against 10 to 18% for ice cream.
- dairyscience.info, an independent dairy education site, says traditional Italian gelato generally has about 8% milk fat.
- A 2020 review in emergent Life Sciences Research gives typical gelato-style mixes 4 to 8% milk fat, 9 to 12% milk solids-not-fat, 15 to 24% sweeteners and 32 to 42% total solids.
For ice cream, the University of Guelph’s Ice Cream Technology e-Book gives milkfat of 10 to 12% for standard ice cream, 12 to 15% for premium and 15 to 18% for super-premium. The e-Book has no section on gelato, so we use it only for the ice cream side.
Air and weight
Overrun is the extra volume that air adds during freezing. At 100% overrun, the frozen product takes up twice the volume of the liquid mix.
Guelph gives about 100 to 120% overrun for standard ice cream, 60 to 90% for premium and 25 to 50% for super-premium. U.S. law also sets a ceiling through weight. The 4.5 pound per gallon floor works out to about 539 grams per liter. At a typical mix density of 1.1 kilograms per liter, that limits U.S. ice cream to roughly 104% overrun. That figure is our arithmetic, not a number in the rule.
The gelato sources do not agree on overrun:
- dairyscience.info says usually under 18%.
- SIGEP World says about 20 to 30%, against the 70 to 100% it calls common in ice cream.
- The 2020 review gives 25 to 60%.
We do not pick one of these. All three put gelato below U.S. ice cream. The higher gelato figures do overlap with Guelph’s range for super-premium ice cream, so the gap depends on which ice cream you compare against.
Serving temperature
Gelato is served warmer than ice cream. Three sources give numbers:
- SIGEP World says gelato is served at about -12 °C (10 °F), against about -18 °C (0 °F) for ice cream.
- dairyscience.info says gelato is served from a cabinet at about -11 to -12 °C.
- Guelph gives a typical ice cream serving temperature of -16 °C (3 °F). At that temperature, about 72% of the water in ice cream is frozen.
The exact ice cream figure varies by source, but gelato always sits a few degrees warmer.
How each is made
Ice cream is frozen while it is stirred in a barrel freezer. Guelph describes a second step after that: the ice cream is hardened in a blast freezer at -30 to -40 °C before it is stored and sold.
Gelato skips that second step. The 2020 review says gelato is made in batch freezers and is not hardened. It is made in batches and served soon after.
At home, the difference comes down mostly to the mix: more milk and less cream for gelato, more cream for ice cream. The Base Builder offers a gelato style and a Philadelphia style as starting points. Both are base formulas built on standard food-science ranges, sized to your machine.