Sour Cream Recipe

Bring ingredients together

Pour 2 cups heavy cream and 1 cup whole milk into a clean saucepan. Warm gently over low heat, stirring occasionally, until the mixture reaches 86°F–95°F (30°C–35°C). If you don't have a thermometer, warm until it's noticeably warm to the touch but not hot — about body temperature.

Cool or adjust temperature if necessary

If the mixture climbs above 95°F (35°C), remove from heat and let cool to the target range. If it is cooler than 86°F, warm slightly; the cultures grow best in the 86°F–95°F range.

Stir 2 tablespoons live plain yogurt (with active cultures) or 2 tablespoons cultured buttermilk into a small bowl to thin slightly. Add a few tablespoons of the warm cream/milk to the starter to temper it, stirring to combine. Then pour the tempered starter back into the warm cream/milk and whisk gently but thoroughly to distribute the cultures evenly.

Transfer the inoculated mixture into a clean glass jar (or cover the bowl tightly with plastic wrap). Keep the jar at a steady warm temperature of about 70°F–78°F (21°C–26°C) for 12–24 hours. To maintain warmth you can: wrap the jar in a towel and place in a turned-off oven with the light on, put in a cooler with a warm water bottle, or use a fermenting box. Check at 12 hours — the mixture should thicken slightly and have a tangy aroma. For thicker, tangier sour cream, incubate up to 24 hours.

When the desired thickness and tang are reached, stir in 1 teaspoon salt (optional) and up to 1 teaspoon lemon juice if you want a brighter tang. Mix gently to combine.

Cover tightly and refrigerate for at least 8 hours (ideally overnight). Chilling stops the culturing and allows the cream to thicken further to the familiar sour cream consistency.

After chilling, taste and adjust salt or lemon if desired. Transfer to a serving container. Homemade sour cream will keep in the refrigerator for 7–10 days. Always use a clean utensil to avoid contamination.