Cultured Butter Recipes

Steps:

• Whisk cream and buttermilk in a large bowl. Cover loosely with plastic and let sit at room temperature until thickened and tastes tangy, at least 12 hours and up to 36 hours (how long this takes will depend on the temperature of your kitchen). Chill until crème fraîche is cool, about 2 hours.
• Transfer crème fraîche to the bowl of a stand mixer fitted with the whisk attachment. Cover space between top of bowl and head of mixer with plastic wrap (this is a must, unless you want cream all over your kitchen). Beat on high speed until butterfat has separated and starts to clump around bottom of whisk, about 5 minutes.
• Line a fine-mesh sieve with cheesecloth. Strain butter mixture through sieve into a small bowl. Pull cheesecloth tightly over butter and form into a ball. Squeeze to drain any excess buttermilk; reserve buttermilk for another use.
• Transfer butter to a clean bowl and knead, adding a few tablespoons of ice water at a time. Drain water off butter as it becomes cloudy; repeat 3-4 times (the water you drain off should become clearer each time). Continue to knead until no liquid remains. Transfer butter to an airtight container or roll into parchment-wrapped logs. Wrap in plastic and chill until ready to use. Serve with sea salt, if desired.
• Do Ahead
• Butter can be made 2 weeks ahead; keep chilled, or freeze up to 3 months.

Steps:

• In a large bowl, sift together flour, baking powder and salt.
• In an electric mixer fitted with the paddle attachment, beat together butter and granulated sugar until lightened in color and fluffy; beat in egg yolk until combined. With mixer running on low, add flour mixture until incorporated.
• Divide dough into two balls. On a clean surface, roll each ball into a 1 1/2-inch log. Sprinkle the demerara sugar over a sheet of parchment. Roll each log in the sugar until the outside of the dough is thoroughly covered. Cover logs tightly with plastic wrap and refrigerate at least one hour, or overnight.
• When you are ready to bake the cookies, heat oven to 325 degrees. Line two baking sheets with parchment. Use large, sharp knife to cut each log into 1/4-inch-thick rounds. Place cookies 1 inch apart on prepared baking sheets. Bake until cookie edges and bottoms are dark golden brown, about 18 minutes. Cool 5 minutes on baking sheets, then transfer to a wire rack to cool completely. Store in a tightly covered container at room temperature.

Steps:

• Let the crème fraîche come to cool room temperature. Spoon it into the food processor, but don't let the bowl get more than half full. Process with the steel blade for 3 to 5 minutes: it will go through stages from whipped to broken and finally into one large clump.
• Drain off the buttermilk (you can keep it for cooking or for making more crème fraîche). Add about 1/2 cup ice water and process for 30 seconds, then drain off and discard the liquid. Repeat two or three times until the liquid is clear. Add 1/8 teaspoon salt for each 2 cups crème fraîche you used, and process to blend. Scoop out the butter, and drain on paper towels in the refrigerator until firm. Wrap tightly in plastic and keep refrigerated.