Lemon Ginger Blackberry Swirl Ice Cream

Ingredients

• 2 cups heavy cream
• 1 cup whole milk
• Peels of two large lemons, removed with a vegetable peeler
• 3 tablespoons minced ginger
• 3 1/2 cups blackberries
• 1 1/4 cup sugar, divided
• 3/4 teaspoon kosher salt, divided
• 6 egg yolks

Directions

1. Set a heavy saucepan over heat and warm the cream with the milk until it reaches a gentle simmer. Add the lemon peels and ginger, put a lid on the pan, take it off the heat, and let everything infuse for 1 hour.
2. Add the blackberries to a blender or food processor and purée only until they collapse into juice with no big pieces left. Pour the purée slowly through a strainer, coaxing it along gently with a fork or whisk. Measure 1 1/2 cups of the strained juice, and throw away the pulp.
3. Pour the strained blackberry juice into a heavy saucepan and bring it to a simmer over medium heat. Cook, stirring often, until it has cooked down to 1/2 cup. Mix in 1/2 cup sugar and 1/4 teaspoon salt, stirring until they disappear into the syrup. Move it to a small container and refrigerate until chilled.
4. In a clean, heavy saucepan, whisk 3/4 cups sugar with the egg yolks until the mixture thickens and turns pale. Once the dairy is done steeping, strain it into the pot, whisking it into the yolk and sugar. Set the saucepan over medium heat and cook, stirring often, until the custard coats the back of a spoon and a path drawn through it with your finger stays clear. Whisk in 1/2 teaspoon salt. Strain into an airtight container and refrigerate overnight.
5. The next day, churn the custard in an ice cream maker following the manufacturer's instructions. As it churns, take the blackberry syrup out of the freezer and stir it until it loosens. Spoon 1/3 of the finished ice cream into an airtight container, then work quickly and spread half of the syrup over it. Add the same amount of ice cream, use the rest of the syrup, and finish with the last 1/3 of ice cream. Freeze until firm, at least 3 hours, and preferably longer.