You can thicken ice cream in an ice cream maker primarily by incorporating thickening agents into the ice cream base before churning. These agents enhance the ice cream's texture, making it richer and creamier.
Common Thickening Agents for Ice Cream
Several ingredients can be used to thicken ice cream. Here's a breakdown:
- Egg Yolks: Egg yolks are a classic choice, adding richness, a smooth texture, and acting as a natural emulsifier.
- How to use: Temper the egg yolks with hot cream and sugar before adding them to the rest of the base. This prevents them from scrambling.
- Cornstarch: A small amount of cornstarch can significantly improve the ice cream's texture by preventing ice crystal formation.
- How to use: Mix the cornstarch with cold milk or cream to create a slurry before adding it to the hot base. This prevents clumping.
- Gelatin: Gelatin provides a smooth, almost chewy texture and helps prevent ice crystal formation.
- How to use: Bloom the gelatin in cold water before adding it to the hot base.
- Tapioca Starch: Similar to cornstarch, tapioca starch helps to create a smooth and creamy texture.
- How to use: Mix the tapioca starch with cold milk or cream to create a slurry before adding it to the hot base.
- Junket Tablets: Junket tablets (rennet tablets) can be used to slightly thicken the base and improve the overall texture.
- How to use: Follow the specific instructions provided on the Junket tablet packaging. They typically involve dissolving the tablet in a small amount of water and adding it to the cooled base.
Considerations When Using Thickening Agents
- Quantity: Start with small amounts of the thickening agent. Too much can result in a gummy or overly dense texture.
- Heating: Most thickening agents require heat to activate their thickening properties. Ensure the base is heated adequately (but not scorched) during the cooking process.
- Tempering (for Egg Yolks): Tempering egg yolks is crucial to prevent them from scrambling when added to the hot cream mixture. Gradually whisk a small amount of the hot cream into the yolks to raise their temperature before adding the yolk mixture back to the pot.
- Dissolving/Slurries (for Starches): Mix starches (cornstarch, tapioca starch) with cold liquid before adding to the hot base to prevent clumping. This creates a smooth slurry.
- Chilling: Always chill the ice cream base thoroughly (ideally overnight) before churning in your ice cream maker. This allows the flavors to meld and further improves the texture.
Example: Thickening with Egg Yolks
- Combine heavy cream, milk, sugar, and any flavorings in a saucepan. Heat gently over medium heat until the sugar is dissolved.
- In a separate bowl, whisk together egg yolks.
- Slowly pour a small amount of the hot cream mixture into the egg yolks, whisking constantly to temper the yolks.
- Pour the tempered yolk mixture back into the saucepan and cook over low heat, stirring constantly, until the mixture thickens slightly and coats the back of a spoon. (Do not boil).
- Strain the mixture through a fine-mesh sieve to remove any cooked egg particles.
- Chill the base thoroughly before churning.
