Sour Cream Substitute Recipe (Using Heavy Cream)
Heavy cream's high fat content (36 to 40 percent) gives the finished product real body and richness, close to true sour cream, while the live bacteria in cultured buttermilk sour and thicken it as it sits at room temperature, converting lactose into lactic acid that coagulates the cream's proteins.
- Prep
- 5 min
- Cook
- 0 min
- Total
- 2405 min
- Servings
- 16
Ingredients
- 2 cups heavy cream
- 3 tablespoons cultured buttermilk
Nutrition per serving
- Calories
- 104
- Protein
- 1g
- Carbs
- 1g
- Fat
- 11g
Based on the recipe as written, one serving. Recalculates if you swap an ingredient above. An estimate only, exact values depend on the specific ingredients used.
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Instructions
- 1Pour the heavy cream into a clean glass jar or bowl, then stir in the cultured buttermilk until fully combined.
- 2Cover the jar loosely with a coffee filter, paper towel, or cheesecloth secured with a rubber band; you want airflow in, but dust and insects kept out.
- 3Let the mixture sit undisturbed at room temperature (68-72°F), out of direct sunlight, for 24 to 48 hours, until it has thickened to a soft, spoonable consistency and smells distinctly tangy.
- 4Stir once, then cover tightly with a lid and refrigerate for at least 4 hours; it will continue to thicken as it chills and firms up.
- 5Use within about 10 days, stirring before each use since some liquid whey may separate on top.
Tips & variations
- For a faster, thinner substitute meant for baking rather than dolloping, whisk 1 cup heavy cream with 1 tablespoon lemon juice or white vinegar and let it sit at room temperature for 10 minutes before using; it won't culture or develop the same tang, but it thickens enough to replace sour cream in batters.
- No buttermilk on hand? Stir in 2 tablespoons of an existing store-bought sour cream with live cultures instead; it works as the starter just as well.
- A warmer kitchen (around 75°F) speeds up culturing; a cooler one can push the process closer to 48 hours, check it periodically rather than going strictly by the clock.
- Because this version keeps all the fat from the heavy cream, it holds up better in hot sauces and gravies than lower-fat store-bought sour cream, which is more prone to curdling near a boil.
Storage & reheating
Store the finished sour cream substitute in a covered jar in the refrigerator for up to 10 days. It is not meant to be reheated; if using it in a hot dish, stir it in off direct heat or at the very end of cooking to prevent it from breaking.
Tips from the Tulo kitchen
- Use a jar that's been through the dishwasher or scalded with boiling water; residual soap or bacteria from a hand-washed jar can throw off how the culture develops.
- If the top layer looks slightly yellow and separated after culturing, that's just butterfat rising, stir it back in rather than skimming it off.
FAQ
Can I use light cream or half-and-half instead of heavy cream?
They'll culture the same way, but the lower fat content means the result stays noticeably thinner and won't hold a dollop shape the way heavy cream does.
Why hasn't my mixture thickened after 24 hours?
The room is likely too cold for the bacteria to work efficiently. Move the jar somewhere warmer, closer to 72-75°F, and give it another 12 to 24 hours before checking again.
Is this the same as creme fraiche?
They're very close. Creme fraiche is traditionally made the same way, heavy cream cultured with a bit of buttermilk, and the main difference is often just naming convention; some versions of creme fraiche use a slightly higher cream-to-culture ratio for an even richer result.
Can I use this in baking as a direct swap for sour cream?
Yes, in a 1:1 ratio. The fully cultured version behaves almost identically to store-bought sour cream in cakes, muffins, and batters.