Hard Ice Cream Recipe

Warm dairy

Combine whole milk and 1 cup of the heavy cream in a medium saucepan. Warm over medium heat until small bubbles form at the edge and steam rises, stirring occasionally. Do not boil.

Whisk yolks and sugar

While the milk warms, whisk the egg yolks and granulated sugar together in a heatproof bowl until the mixture lightens slightly and becomes smooth.

Temper yolks

Slowly pour about 1/2 cup of the hot milk mixture into the yolks while whisking constantly to temper. Then gradually whisk the tempered yolks back into the saucepan with the remaining warm milk and cream.

Cook custard

Cook the mixture over medium-low heat, stirring constantly with a wooden spoon or heatproof spatula, scraping the bottom and sides. Heat until the custard thickens enough to coat the back of the spoon (approximately 170–175°F / 77–80°C). Do not let it boil or the eggs will curdle.

Add flavor and salt

Remove the saucepan from heat. Stir in the vanilla extract and fine sea salt.

Make slurry

If using cornstarch, mix the cornstarch with the 1 tsp cold water until fully dissolved to make a slurry.

Temper and incorporate: Return the custard to very low heat and whisk in the cornstarch slurry. Continue to cook and whisk for 1–2 minutes more until the custard thickens slightly further. Remove from heat.

Cool the custard quickly

Pour the hot custard through a fine-mesh sieve into a clean bowl to remove any bits of cooked egg. Set the bowl in an ice bath (place the bowl in a larger container filled with ice and cold water) and stir the custard occasionally until it cools to room temperature, about 20–30 minutes.

Add remaining cream

Once cooled to room temperature, stir in the remaining 1 cup of heavy cream. Cover the surface with plastic wrap (touching the custard) and chill in the refrigerator for at least 4 hours or overnight. Chilling improves texture and helps the mixture freeze more evenly.

Churn

When the custard is fully chilled, churn it in an ice cream maker according to the manufacturer's instructions until it reaches a soft-serve / thick consistency (usually 20–30 minutes).

Harden

Transfer the churned ice cream to a shallow, airtight container and press a piece of parchment or plastic wrap directly onto the surface to minimize ice crystals. Freeze for at least 4 hours (preferably 6–8 hours) until firm/hard.

Serve

Remove from the freezer 5–10 minutes before scooping to slightly soften. Scoop and serve as desired.