Mojito Sorbet

Sour lands before sweet, then the mint opens the whole mouth cold, and a faint warmth from the rum is the last thing to leave.

By the time it reaches the spoon it has already begun to soften, and it should: with no fat and no milk solids there is nothing to slow the melt, so the edges go liquid while the centre still holds. Sourness lands before sweetness and lands fast, because acid needs no fat to carry it. Then the mint opens the back of the mouth and keeps everything feeling colder than the freezer ever made it, which is why the herb stops at 30 g; in water, with nothing to mask it, menthol reads loud. What stays last is the rum, a faint warmth under the cold, and 4 g of carob seed flour is the only body on offer.

The usual rule of 350 to 650 g of fruit per kilo does not apply to citrus. Lime and lemon are used between 180 and 280 g/kg because pH 2.2 to 2.4 and the titratable acidity take over the palate long before the fruit takes over the solids. Two hundred grams of Tahitian lime is the classic lime sorbetto dose. Mint sits at 30 g, lower than in a mint gelato, since a water base has no fat to soften menthol and the same amount reads sharper.

Rum at 18 g is the dangerous lever and also the point of the recipe. It carries PAC 296, so those 18 g alone spend around 53 of the 375 points available to a sorbet, and that is exactly why a mojito sorbet never sets hard the way a plain lime sorbet does. The sugars then had to be chosen to pay for it: 135 g of sucrose, 25 g of dextrose and 120 g of glucose powder, the last one running POD 44 against PAC 72, which buys solids and sweetness without pushing the freezing point any further down. Final PAC 323.62.

Ingredients

Makes 1000 g of finished base.

Method

Hot syrup, cold pour, two stirs in a metal tray

1. 1Whisk every dry ingredient together first: sugars, milk powder, stabiliser and salt. Dry-blending them stops the stabiliser clumping when it meets liquid.
2. 2Warm the liquids to 40 C (104 F), then rain the dry mix in while whisking hard.
3. 3Heat to 82 C (180 F) and hold for 2 minutes so the stabiliser hydrates.
4. 4Chill in an ice bath to under 5 C (41 F) within 2 hours. Slow cooling is where bacteria and coarse crystals both start.
5. 5Age 6 to 12 hours in the fridge under 5 C (41 F). This is when the stabiliser and the milk protein take up water.
6. 6Freeze in a shallow metal pan 2 to 3 cm deep, breaking the crystals with a fork every 30 to 40 minutes, 4 to 6 times.
7. 7Freeze firm, then temper 10 to 15 minutes in the fridge before scooping.

The balance

All six against the professional range for Sorbetto.

PAC 323.62 inside 275 to 375 is the number the whole sheet turns on, and the rum eats a large slice of it before any sugar is weighed. That is why the sugar is split three ways instead of being one sucrose line: glucose powder at POD 44 and PAC 72 adds 120 g of solids and body at a low antifreeze cost, dextrose adds 25 g of freezing point depression where it is wanted, and sucrose carries the rest. POD closes at 207.66, mid range in 175 to 240, which is the sweetness needed to hold 200 g of lime in check without the thing tasting like syrup. Solids land at 30.99 percent against 27 to 35, helped by 14 g of inulin that contributes body with no sweetness of its own, and sugars at 27.52 against 23 to 32. Water reads 68.41 against 65 to 73, fat 0.03 against a 2 percent ceiling and protein 0.20 against 0.5, both of which confirm this is a true sorbet rather than a lightened dairy base.

If it goes wrong

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