Ice Cream and Frozen Desserts
Ice Cream and Frozen Desserts tests mix formulation, freezing, overrun and storage defects. Ice cream is a foam and emulsion; frozen dessert may use vegetable fat instead of milk fat.
Mix composition and processing
A typical ice cream mix contains about 10-12% fat, 10-11% milk solids-not-fat, 14-16% sugar, 0.2-0.5% stabiliser and 0.2-0.3% emulsifier, with total solids about 36-40%. The mix is pasteurised, homogenised, aged, frozen with incorporation of air, filled and hardened. Overrun is the volume of air incorporated, expressed as a percentage of mix volume.
Worked example
100 kg mix has density 1.10 kg/L. Mix volume = 100 / 1.10 = 90.9 L. At 50% overrun, frozen volume = 90.9 × 1.50 = 136.4 L. The added volume is air, not product solids. If overrun is calculated on frozen product volume instead, the percentage differs, so state the basis.
Traps
Do not confuse overrun with total solids. Too much sugar lowers the freezing point and makes the product soft. Large ice crystals result from slow freezing or heat shock. Frozen dessert is not automatically ice cream; fat source and legal standards differ. Stabiliser excess causes gummy texture.