Recently, I came across an article titled “Here’s the Scoop”, written by Molly O’Neill. It’s in the Aug/Sept issue of Saveur magazine. In the article she talks about the science of making “rich and creamy” ice cream. I had a vague idea of the “science”, so my interest was peaked.
She also writes about one entrepreneur, Jeni Britton and Jeni’s Splendid Ice Cream stores in Ohio and a lonely one in Tennessee. Jeni has a new book out called, Jeni’s Splendid Ice Creams at Home (Artisan, $23.95). In it she walks the readers through her novel technique, for what Molly believes is some of the creamiest, most flavorful ice cream on which she’s ever laid her tongue.
The long and the short of her technique is that she uses, among other ingredients, a small amount of corn starch. This replaces the traditional egg yolks as the binder for the frozen emulsion. She also boils the liquid to reduce the water content, thus concentrating and denaturing the milk proteins which then allows a greater ability to bind the remaining water and fat. She also uses some cream cheese, which is high in casein proteins; another binder.
She goes on in more detail about the “science ” and has included an ice cream base recipe, plus three variations: Blackstrap Praline, the Darkest Chocolate in the World, and a Beet with Mascarpone, Orange Zest, and Poppy Seeds. Since Jeni said that her base  is a starting point for any ice cream, I of course came up with my own version; a Peanut Butter-Chocolate Swirl recipe.
2 cups whole milk
4 teaspoons (1/2 ounce) cornstarch
1 ¼ cups heavy cream
1 cup (8 ounces) smooth natural peanut butter, divided
2/3 cup brown sugar
2 tablespoons light corn syrup
1 pinch of sea salt
2 teaspoons vanilla extract
¾ cup hot fudge sauce*
In a bowl, stir together 1/4 cup milk and the cornstarch; set slurry aside. Place the cream cheese and ½ cup of peanut butter in a bowl and set that aside as well.
In a 4-quart saucepan, whisk together the remaining milk, cream, sugar, corn syrup, and salt; bring to a boil over medium-high heat.
Cook for 4 minutes and then stir in the cornstarch slurry. Return the mixture to a boil and cook, stirring until thickened, about 2 minutes.
Pour ½ cup of the hot milk mixture into the bowl of the peanut butter/cream mixture and whisk until smooth. Whisk in the remaining milk mixture and vanilla extract.
Place the bowl with the mixture in an ice bath and stir occasionally until cool. Cover and refrigerate until cold; 6 – 8 hours, or over night.
Pour mixture into an ice cream maker and process according to manufacture’s instructions. Transfer to a freezer-proof bowl and quickly swirl in remaining 1/2 cup peanut butter and ¾ cup chocolate sauce. Cover and freeze until hard. Serve with remaining hot fudge sauce, or use the sauce to make another batch of ice cream.
Hot Fudge Sauce
Makes about 2 cups
2/3 cup heavy cream
1/2 cup light corn syrup
1/3 cup packed dark brown sugar or dried cane juice
1/4 cup (1 ounce) unsweetened Dutch-process cocoa powder
1/4 teaspoon salt
6 oz fine-quality bittersweet chocolate (not unsweetened), finely chopped
2 tablespoons unsalted butter
1 teaspoon vanilla
Bring cream, corn syrup, sugar, cocoa, and salt to a boil in a 1 to 1 1/2-quart heavy saucepan over moderate heat. Reduce heat and cook at a low boil, stirring occasionally, 5 minutes, then remove from heat.
Add butter, vanilla, and chocolate and stir until smooth. Cool cool completely before adding to churned ice cream.