The Scientific Architecture of Smooth Ice Cream

In a saucepan over medium-low heat, combine 2 cups heavy cream, 1 cup whole milk, and half of the granulated sugar (6 tbsp). Heat until steam rises and small bubbles form around the pan edges ($\sim 175^\circ\text{F} / 80^\circ\text{C}$). Do not boil.

Whisk 5 egg yolks and remaining sugar (6 tbsp) in a bowl until pale and thickened. Slowly pour a thin, steady stream of hot cream into the eggs while whisking continuously to temper the proteins without scrambling them.

Return the tempered mixture to the saucepan over low heat. Stir continuously with a heatproof spatula until the custard thickens to the napé stage (coats the back of a spoon and holds a clear finger line).

Pour custard through a fine-mesh strainer. Stir in 2 tsp vanilla and ⅛ tsp salt. Cover surface directly with plastic wrap and refrigerate for at least 4 hours (or overnight). Churn in an ice cream maker for 20 to 25 minutes, then freeze in an airtight container for 4 hours until firm.

For the No-Churn method: Pour 2 cups thoroughly chilled heavy cream into a chilled bowl. Beat on medium-high speed using a mixer until stiff, stable peaks form.

In a large bowl, whisk 14 oz sweetened condensed milk, 2 tsp vanilla, and ⅛ tsp salt. Stir 1 cup of whipped cream into the condensed milk to lighten it, then gently fold in the remaining whipped cream with a rubber spatula until unified.

Transfer the no-churn mixture into a metal loaf pan or airtight container. Cover tightly and freeze for at least 6 hours until firm and scoopable.