Making Cultured Sour Cream at Home
This is a slow process of transformation. By giving the cream time to rest, you allow the bacteria to consume the lactose, thickening the texture and sharpening the flavor into something far more complex than what you find in a plastic tub.
Sterility is your best friend.
Because you are inviting bacteria to grow, ensure your glass jars and utensils are sterilized in boiling water before starting. Use high-quality cream without stabilizers or thickeners for the cleanest result.
- glass mason jar with lid
- saucepan for sterilizing
- clean kitchen towel
What goes in.
- 2 cupsheavy whipping cream (no additives/carrageenan)
- 2 tbspfresh cultured buttermilk or store-bought sour cream with live cultures
Controlled Warmth
The cultures thrive between 70°F and 75°F. Keep the jar in a warm, draft-free spot like the inside of an oven with the light on, not the heat.
The method.
Sterilize
Boil your jar and lid for 5 minutes, then let them air dry completely.
Inoculate
Pour the cream into the jar and stir in the starter. Use a clean, sterilized spoon to ensure it is thoroughly combined.
Cover and Rest
Cover the jar loosely with the lid or a clean cloth secured with a rubber band. Place it in a warm, dark spot for 18 to 24 hours.
Test and Chill
Check the jar by tilting it; the cream should hold its shape like soft custard. Once set, tighten the lid and refrigerate for at least 6 hours to stop the culture and firm up the final texture.
When it doesn't go to plan.
If your kitchen is cold, wrap the jar in a thick towel to maintain a steady temperature.
Save two tablespoons of your finished batch to use as the starter for your next one.
If you see a small amount of clear liquid (whey) on top after setting, simply stir it back in or pour it off before serving.
The ones that keep coming up.
How do I know if it has gone bad?
Fresh cultured cream has a bright, clean, acidic scent. If it smells like yeast, rot, or has visible mold growth of any color, discard the entire batch immediately.
Why didn't my cream thicken?
The cream was likely too cold, the starter was inactive, or the room temperature was too low for the bacteria to reproduce. Check your starter's expiration date and try to find a warmer spot.