How to Make an Ice Cream Base

How to Make a Custard Base

1. In a heavy-bottomed, nonreactive saucepan, heat over medium heat the milk (or combination of milk and cream), a pinch of salt, and half the sugar. Watch the pan carefully to make sure the mixture doesn’t boil over. Once the mixture comes to a simmer, turn the heat off and cover the pan so that it stays warm.
2. In a separate bowl, combine the egg yolks and the remaining sugar and beat with a whisk until the mixture is pale and forms thin ribbons in the whisk’s trail.
3. Prepare an ice bath by putting ice and enough water to cover it in a large bowl and placing a slightly smaller bowl inside the ice bath. It’s important to prepare the ice bath early so that you can pour your custard into the smaller bowl as soon as it’s done cooking to cool it down as quickly as possible.
4. Temper the egg yolks by adding some of the warm dairy mixture slowly, one ladleful at a time, into the whisked egg yolks so that they don’t heat up too quickly and scramble. While you’re pouring with one hand, use the other hand to whisk the dairy mixture into the egg yolks. If your bowl wobbles or slides around while you’re working, wrap a damp dish towel around it to keep it in place.
5. Once you’ve added 5–6 ladles of the warm dairy mixture to the egg yolks, you can pour the dairy and egg yolk mixture back into the saucepan, scraping the bowl with your spatula to ensure you get all of it into the pan.
6. Turn the heat to medium-low and cook the custard slowly, stirring it constantly with your spatula. Be sure to scrape the bottom of the pan frequently so that the custard doesn’t scorch and the eggs don’t scramble on the bottom.
7. Cook the custard for 5–8 minutes or until steam begins to rise from it, your instant-read thermometer reads 175°F, or the custard coats the back of your spatula or spoon thick enough that your finger leaves a trail when dragged across it.
8. Turn the heat off promptly and pour your custard through a strainer placed over the clean bowl resting in your ice bath. Stir the custard occasionally to help it cool to room temperature.
9. Once the custard has reached room temperature, pour it into a container, seal it tightly, and refrigerate it until it’s thoroughly chilled—at least 8 hours and preferably overnight. This process, called aging, allows the various flavors time to blend and distribute themselves fully throughout the custard.

How to Make a Non-Custard Base

1. Pour the milk and/or cream into a heavy-bottomed saucepan along with the sugar, salt, and any flavorings such as vanilla bean or preserves. Warm the mixture over medium heat until the sugar dissolves. Take care not to overheat the mixture, as overheating will harm the final texture of your ice cream.
2. Turn the heat off and allow the base to cool to room temperature. If your recipe calls for reserving some of the cream and adding it to the base after it has cooled, add it at this point.
3. Transfer the base to a container, seal it tightly, and let it chill thoroughly in the refrigerator—at least 8 hours and preferably overnight.