Smetana is a staple of Russian cuisine, reminiscent of sour cream but closer in texture to a thin, runny ranch dressing. When I spent a couple months in Moscow in college, breakfast was always a hard-boiled egg with fresh peas and a dollop of smetana — a simple yet filling meal. Use it as a salad dressing, mix it into soups, or rub it onto a roast. There is an additional recipe further below if you would like to make it into smetana butter.

This will take a few days to make, so plan ahead! One batch makes a quart. A half batch will fill a pint-sized jar up to the brim. Recipe from Kachka: A Return to Russian Cooking by Bonnie Frumkin Morales. New York: Flatiron Books, 2017. 

1 qt. heavy cream
1/4 c. buttermilk (or 3/4 tsp. lemon juice + milk to fill to ¼ cup line)

Halved amount:
2 c. heavy cream
2 tbsp. buttermilk (or 1/3 tsp lemon juice + milk to fill to 1 tbsp. line, plus a full tsbp. milk)

Bring the heavy cream to room temperature and mix it with the buttermilk. Let the mixture sit out at room temperature, loosely covered, for 12 hours.

Transfer to the refrigerator for 12 hours.

Return to room temperature to finish, 10-18 hours, depending on the temperature. Store in the refrigerator.

It will be done when it has thickened. If it still feels like cream after the final room temperature stage, give it more time in the fridge. It may take another day or two.

Smetana Butter
You can use smetana to make a tangy butter that can be subbed into other recipes when you want something more complex than regular butter.

Smetana (however much you want to use)
Kosher salt (to taste)

Use smetana that has been properly chilled in the refrigerator. Transfer to a stand mixer with a whisk attachment, and use a splash guard (or be prepared for a bit of spatter). Whisk on high speed, past the point of whipped cream, until the mixture clumps around the whisk, and a pool of liquid separates out at the bottom. You can’t overmix, so don’t hold back.

If you don’t have a stand mixer and/or a splash guard: pour the smetana and salt into a zippered plastic bag. Make sure it’s completely sealed, then shake it. And shake it. And shake it. Or hand it over to a high-energy child, or attach it to the collar of a hyperactive dog. It’s done when you get solid matter.