Cultured Butter Recipes

Steps:

• Combine cream and yogurt in a large jar or bowl. Seal jar well and shake aggressively until combined, or whisk well if using a bowl. Cover jar or bowl with a clean kitchen towel and let mixture sit in a warm area of your kitchen for 18 to 36 hours; it should thicken and taste rich and tangy.
• Seal the jar or cover bowl tightly with plastic wrap and refrigerate until it reaches 60 degrees, 1 to 2 hours. If you refrigerate it longer, allow mixture to warm slightly at room temperature before proceeding.
• Line a fine-mesh sieve with a double layer of cheesecloth and place it over a large bowl. Make sure there is plenty of extra overhang of cheesecloth.
• In the bowl of a food processor, add the thickened butter mixture and process on high until the yellow curds begin to separate from the buttermilk, 2 to 3 minutes. It will have the appearance of liquidy cottage cheese.
• Slowly pour the buttermilk through the mesh sieve and then dump the butter curds in. Let sit for 1 to 2 minutes, allowing buttermilk to drip through. Gather the ends of the cheesecloth up and around the butter, pushing the curds down and into a ball. Twist the cheesecloth and squeeze the ball to extract as much buttermilk as possible. You will be left with a butterball.
• Pour the buttermilk into a separate container and reserve for another use. Place the butterball in the empty bowl. Be sure to squeeze out all excess butter from the cheesecloth. Pour 1/3 cup of ice water over the butter and, using a spatula, "wash" the butter, folding it over itself and pressing down to extract the extra buttermilk. Drain off the milky liquid and discard it; repeat this process until the liquid is clear, 4 to 6 times. The butter will start to harden; at that point your hands may work better than the spatula.
• Place the butter on a clean kitchen towel and pat lightly to remove excess moisture. Knead a few times with your hands and pat dry again; this will help extend its storage life. Sprinkle the finished butter with salt and knead a few more times to combine.
• Lay out a sheet of parchment paper, or two if you would like to divide the batch in half, and place the butter on the paper. Form the butter into a log and then roll it up in the paper and twist the ends to seal. Make sure the log has a uniform thickness throughout. Refrigerate until ready to use. The butter will last about a month in the refrigerator.

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.