Which sugars to use in ice cream and gelato

Sugar does two jobs in ice cream: it sweetens, and it keeps water from freezing so the ice cream stays soft. Different sugars do those two jobs in different amounts. Mixing them lets you set sweetness and softness separately.

The sugars

• Sucrose (table sugar). The reference: sweetness 100, softening 100. Most of the sugar in most recipes.
• Dextrose. Less sweet (70) but softens almost twice as much (190). The usual way to make ice cream softer without making it sweeter. Keep it to about a quarter of the added sugar.
• Invert sugar and honey. Sweeter than sugar and soften like dextrose. Keep ice cream smooth; honey adds its own flavour.
• Glucose syrup. Not very sweet and softens less than sugar. Adds body and chew, and slows ice crystals.
• Lactose. The sugar in milk. Barely sweet. Too much milk powder brings too much lactose, which can crystallise and feel sandy.

Sugar substitutes

• Allulose. A rare sugar: 70% as sweet as sugar and softens like dextrose. It isn’t counted as sugar on US labels.
• Sugar alcohols (erythritol, xylitol, maltitol). Sweeten and soften, with fewer calories. Erythritol softens a lot and can taste cool; too much of any of them can upset the stomach.

A simple starting mix

For gelato, use mostly sucrose, with dextrose at up to a quarter of the added sugar. Add invert sugar or glucose syrup only when you want a specific texture. In Scoopable, the gelato template starts this way and keeps dextrose to a quarter for you.