SOUR CREAM WITH BLUEBERRY SWIRL ICE CREAM
For quite some time, Ben has been keen on trying to make ice cream using sour cream, and when we started working on this book and were discussing the recipes we wanted to include, sour cream was at the top of the list as an ingredient we wanted to work with. Our coauthor, Olga, who is Russian and loves all things sour cream, couldn’t agree more.
Sour cream is created by introducing cream to certain kinds of lactic bacteria and allowing the cream to “sour,” or ferment. Often, sour cream is confused with its fattier cousin, crème fraîche, but unlike sour cream, crème fraîche doesn’t curdle when you cook with it, thanks to its higher fat content, and sour cream is tangier on your palate than crème fraîche is. It’s that second quality that made us think of sour cream as a flavoring for ice cream. We complement the sour cream by adding a swirl of homemade blueberry compote at the end.
MAKES ABOUT 1 QUART
SPECIAL EQUIPMENT
Immersion blender
FOR THE BLUEBERRY COMPOTE
½ cup fresh or frozen blueberries
2 tablespoons (25 grams) sugar
A drop or two of fresh lemon juice
FOR THE SOUR CREAM ICE CREAM
1½ cups heavy cream
2 tablespoons whole milk
½ cup plus 2 tablespoons (125 grams) sugar
¼ teaspoon (1 gram) kosher salt
8 large egg yolks
1½ cups sour cream
1. To make the blueberry compote, in a small saucepan, combine the blueberries, sugar, and lemon juice and bring to a gentle simmer over medium heat. Cook the berries until they slump and the syrup thickens, 5 to 7 minutes. (If you are using frozen berries, this process could take a bit longer, since the berries start out with more moisture.) Remove from the heat and set aside to cool to room temperature. Transfer to an airtight container and refrigerate until ready to use.
2. To make the sour cream ice cream, pour the cream and milk into a double boiler or a heatproof bowl set over a saucepan of simmering water (the bottom of the bowl should not touch the water). Whisk in ½ cup (100 grams) of the sugar and the salt and stir until they have dissolved. Warm the mixture until you see steam rising from the top.
3. Meanwhile, prepare an ice bath in a large bowl. Set aside.
4. In a medium bowl, with a kitchen towel underneath it to prevent slipping, whisk together the egg yolks with the remaining 2 tablespoons (25 grams) sugar until uniform. While whisking, add a splash of the hot dairy mixture to the yolks. Continue to add the dairy mixture, whisking it in bit by bit, until you’ve added about half. Add the yolk mixture to the remaining dairy mixture in the double boiler. Set the heat under the double boiler to medium and cook the custard, stirring continuously with a wooden spoon and reducing the heat to medium-low as necessary, until steam begins to rise from the surface and the custard thickens enough to coat the back of the spoon. Hold the spoon horizontally and run your finger through the custard. If the trail left by your finger stays separated, the custard is ready to be cooled.
5. Strain the custard into a bowl and stir in the sour cream until incorporated. Using an immersion blender, buzz the mixture until emulsified. Place the bowl over the prepared ice bath and stir for 3 to 5 minutes, or until the custard has cooled. Transfer the custard to a quart-size container, cover, and refrigerate for at least 4 hours or, preferably, overnight.
6. Pour the chilled custard into an ice cream maker and freeze according to the manufacturer’s instructions. Place the container in which you refrigerated the custard in the freezer so you can use it to store the finished ice cream. Churn the ice cream until the texture resembles “soft serve.” Fold in the blueberry compote until there are pockets of plain ice cream and ripples of blueberry swirl. Transfer the ice cream to the chilled storage container and freeze until hardened to your desired consistency. Alternatively, you can serve it immediately—it will be the consistency of gelato. The ice cream will keep, frozen, for up to 7 days.
ben’s note Most industrially produced sour cream will contain thickening agents: guar, rennet, carrageenan—even gelatin! Real sour cream, which contains only cream and lactic bacteria, shouldn’t have any of those things; we urge you to seek out the best-quality sour cream you can find—it will make a great difference in your ice cream.