- 1 quart heavy whipping cream (NO stabilizers or emulsifiers)
- 2 tablespoons plain Greek yogurt
- 1 sprig rosemary
- 2 sprigs thyme
- 1 sprig sage
- 1 tablespoon fermented lemon rind, rinsed and chopped
- 1/2 tsp salt (optional)
- Rinse the herbs well and pat dry with a paper towel.
- Infuse the cream with the herbs and lemon by combining the herbs, lemon, and cream in a small pot. Heat with frequent stirring until it begins to simmer, then immediately remove from heat.
- Strain out the herbs and lemon, and transfer the cream to a large glass jar to cool.
- Culture the cream by combining the cooled cream and yogurt. Stir well to combine.
- Cover the jar of cream mixed with yogurt with a cloth lid.
Allow the cream mixture to ferment at room temperature for about 24 hours. The mixture will thicken and become sour, similar to yogurt.
- Chill the cultured cream in the fridge for about 2 hours.
- Pour the cold cream mixture into your blender, and turn it on medium speed.
- Blend the cream until it becomes whipped cream and continue to blend until large chunks form (that’s butter!). This takes between 2 and 10 minutes, depending on the blender.
- Let it sit in the blender for a couple of minutes, and you will see the butter separated from the buttermilk.
- Pour the buttermilk into another container, using a mesh sieve to hold the butter back in the blender. (You can use the cultured buttermilk for baking)
- Add ice-cold water to cover the butter in the blender. Cover and pulse a few times until the water turns cloudy. Let it stand a moment to separate, then pour off and discard the liquid. Repeat four times until the liquid is primarily clear after blending.
- If you are salting the butter, add it now and pulse a few times to combine. Place the blender in the fridge and let the butter solidify.
- Drain off any more liquid. Once you’ve drained as much buttermilk liquid as possible, scoop the cold butter onto a folded 12 x 12 square of cheesecloth.
- Bring the edges of the cheesecloth together over the butter and squeeze any remaining liquid out of the butter with your hands.
- Scoop the butter out of the cheesecloth and store it in an airtight container in the fridge.