Learning Objectives
Describe the types of churned-frozen ice cream.
Explain how ingredients affect the outcome of an ice cream.
Describe frozen desserts such as gelato, sorbet, sherbet, and granita.
Explain the process for producing molded frozen desserts.
Explain the types of still-frozen desserts.
- Aging allows the protein network to absorb more of the moisture present in the base, leaving less water available to form ice crystals, resulting in a smoother ice cream.
The fat and emulsifiers contributed by the egg yolks and because cooking the proteins present in the eggs binds or holds moisture, interfering with the formation of ice crystals, which results in smaller ice crystals, thus lending a smoother texture to the finished ice cream.
Milk powder is often added to ice cream made without eggs. It helps to bind excess liquid in the mixture that would otherwise result in the formation of large ice crystals.
- The butterfat content of ice cream ranges from 10 to 14 percent.
- Invert sugars such as corn syrup and glucose syrup improve texture and help prevent the formation of large ice crystals.
For soft fruits, bring the syrup to a boil, then remove from the heat, add the fruit, cover, and allow to stand until cool. Drain the fruit and chill. Fold the poached fruit into the soft ice cream just as it comes from the machine. For harder fruits, use the same technique but leave the fruit in the syrup for approximately 15 minutes, making sure the temperature is maintained between 160° and 180°F/71° and 82°C.
For very strongly flavored fruits such as passion fruit, or fruit concentrates, replace only half of the milk in the formula with the fruit purée. When using a pulpy fruit purée to flavor an ice cream, homogenizing the mixture before freezing will create a better emulsion.
If 10 percent of the sugar in a formula is added in the form of corn syrup, a smoother texture will result.
Sorbets made with fruit juice as opposed to purée tend to separate. Juices lack the pulp contained in a purée, which helps to sustain the mixture of water, flavorings, and sugar.
Chemical stabilizers such as xanthan gum extend suspension, promote air incorporation, even out air bubble distribution, and assure the cohesion of a finished product during storage.
When making sorbets or sherbets, remember that the sugar content of most fruits varies according to ripeness. Therefore, it may be necessary to adjust the consistency of the sorbet base by adding more liquid if it is too sweet or more sugar if it is too tart. Let taste be the most important factor.
- If there is too much sugar, granita will not freeze.
- If there is not enough sugar, it will become too hard.
To unmold the dessert, immerse the mold briefly in warm water and wipe dry before unmolding, or gently and quickly warm it over an open flame or using a blowtorch or blow dryer.
Invert the dessert onto the plate and gently lift the mold away, being careful not to touch the sides.