How this calculator works
Ice cream is a foam of air, ice crystals, fat globules and a concentrated sugar solution. The mix composition decides how hard it freezes and how sweet it tastes. Fat usually makes up 10 to 16 per cent of a premium mix, sugar 14 to 18 per cent, and total solids 36 to 42 per cent. More sugar lowers the freezing point, which keeps the ice cream scoopable from the freezer. This calculator adds the fat, sugar, protein and water in each ingredient and estimates the freezing point from the sugar content alone. Milk salts and the concentration that happens as ice forms push the real serving temperature lower, so treat the freezing point as a guide.
Formula
total mix weight = milk + cream + sugar + yolks. fat or sugar percentage = grams of that component / total weight x 100. freezing point depression = 0.0544 degrees Celsius per percentage point of sugar in the mix, from 1.86 degrees per molal and a sucrose molar mass of 342.3 g/mol. estimated freezing point = 0 degrees Celsius - depression. energy per 100 g = 9 x fat percentage + 4 x carbohydrate percentage + 4 x protein percentage.
Worked example
A mix of 500 g whole milk, 300 g 35 per cent cream, 150 g sugar and 4 yolks weighs 500 + 300 + 150 + 68 = 1,018 g. It contains 16.25 + 105 + 18 = 139.3 g of fat, so fat is 13.7 per cent. Sugar is 24 + 8.4 + 150 + 2.4 = 184.8 g, or 18.2 per cent. The estimated freezing point is 0 - 0.0544 x 18.2 = -0.99 degrees Celsius, and the energy is about 209 kcal per 100 g.
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Frequently asked questions
What is a good fat content for ice cream?
Premium ice cream is usually 12 to 16 per cent fat, super-premium 16 to 20 per cent, and a lighter everyday mix 8 to 12 per cent. More fat gives a richer texture but mutes flavour release and can taste greasy above about 20 per cent.
Why does more sugar make ice cream softer?
Dissolved sugar lowers the freezing point of water, so less ice forms at freezer temperature. That keeps the mix scoopable but also makes it taste less cold. A mix that is too sweet will not freeze firmly; one with too little sugar freezes hard and icy.
Does the calculator include stabilisers or emulsifiers?
No. Gelatin, xanthan gum and commercial stabiliser blends are used at about 0.2 to 0.5 per cent and change texture and ice crystal size rather than the basic fat and sugar figures. Add them to the recipe by weight, not to this composition check.
How accurate is the freezing-point estimate?
It is a chemistry estimate from the sugar content. Milk proteins, lactose and salts also contribute, and the mix becomes more concentrated as ice forms, so real serving temperatures are lower than the initial freezing point. Use the figure to compare recipes, not to set a freezer thermostat.