Sour Cream is a dairy product obtained by fermenting regular cream with beneficial lactic acid bacteria. Traditionally, sour cream was made by letting cream that was skimmed off the top of milk ferment at room temperature — the bacteria that naturally developed during fermentation thickened the cream and made it more acidic, which was a natural way of preserving the cream.

Cultured Sour Cream is a similar product to the traditional sour cream. It is made by inoculating the cream with lactic acid which produces a thick, viscous, slightly tart sour cream.

Our Sour Cream starter makes genuine luscious and thick Sour Cream of exceptional quality with a traditional rich flavor and a fresh mild taste with just a slight tartness.

You can adjust the thickness and the flavor of your sour cream by controlling the time of incubation, making it anywhere from creamy liquid to thick and smooth yogurt-like consistency, and from mild and sweet to nicely tart and even sour flavor. See below for instructions on how to do this.

This is a heirloom Sour Cream starter with live active bacteria – you can reuse sour cream from your previous batch to culture your new batch, for as long as you wish.

Sour Cream is a mesophilic product, which means you can culture it at room temperature.

It is super easy to make Sour Cream using our Bacillus Bulgaricus Sour Cream starter culture.

All you need is a pack of our starter and cream.

Our Sour Cream starter works with any type of dairy cream — raw or pasteurized regular cream, double cream, half-and-half, or a mixture of cream and milk.

You can also use non-dairy milk, however when using vegan milks you might need to add a thickener as those won’t thicken on their own.

The higher the fat of your original cream, the thicker and more delicious your sour cream will become. When using a higher fat content cream, you can use our Sour Cream starter to make cultured creme fraîche, whipped cream, and more.

Making Sour Cream comes down to bring your cream to room temperature (around 76°F / 24°C), adding the starter, stirring well until it dissolves and then incubating it at room temperature until it sets, for about 12–14 hours. As simple as that!

However, here are some more detailed instructions as well as some tips on tweaking the consistency and the taste of your sour cream.

There are two ways to make Sour Cream – the traditional mesophilic way and a faster, fail proof way, which I personally recommend as it yields results faster. The two methods are explained below.

Traditional Mesophilic Sour Cream Instructions

Use this method if you prefer to make your Sour Cream the traditional way, manually or with the help of a yogurt-making machine.

1. Let your cream warm up to room temperature (around 76°F / 24°C) on its own, or if you want to speed up the process, gently heat it up that temperature.
2. Add the starter from the pack to the cream and stir until it dissolves.
   Note: Do not whisk. Whisking introduces air bubbles into the cream and that slows down incubation.
3. Cover the jar with a lid or a towel to keep the cream clean from dust and air-borne particles. Towel is maybe better because it allows air to still go in, which speeds up activation a bit.
4. Let the cream sit for about 24 hours and then check if it has set (firmed up).
   Note: Sour Cream has set if it separates somewhat cleanly from the sides of the jar when you tilt the jar. It should be firm at the top, while still being somewhat watery further down, but it should separate easily from the jar when tilted.
5. If it hasn’t set in 24 hours, then keep it going and check every 2-4 hours until it sets. It may take up to 72 hours to set depending on the ambient temperature and other conditions in your environment.
6. Move the Sour Cream to the fridge for at least 2 hours so it can properly firm up. Cooling the Sour Cream will help it thicken and improve its taste.
7. Enjoy!

Do not forget to save a cup of the ready-made sour cream to use for making your next batch! Keep that in the fridge and make sure you use it to make your new yogurt within 3-4 days to ensure all bacteria is viable and in great condition.

Fail Proof Sour Cream Making Instructions

Use this method if you have difficulties getting good results with the traditional method or would like to get your results faster, try this fail-proof manual method instead. It is a manual method that allows you to get your Sour Cream to turn out faster compared to when using the traditional method above.

This method relies on keeping the cream warm during incubation, which speeds up the process by making the culturing environment more beneficial to the development and procreation of the lactic acid bacteria.

1. Heat up the cream up to just over 113°F / 45°C
2. Set aside a small cup from the cream
3. Keep the rest of the cream in the container you heated it (or distribute it to the culturing containers – 1L mason jars work best)
4. When the cream in the cup is at 86°F / 30°C (it will feel lukewarm to the touch), add the starter from the pack to it then gently stir it until it dissolves, may take a couple of minutes.
   Note: You are adding the starter to the cream in the small cup, not to the cream in the containers!
5. When the rest of the cream (in the containers) is ready, at around 90°F / 32°C, distribute the cream from the cup (the one with the starter) to the jars, proportionally to their volume.
6. Gently stir the cream in the jars.
   Note: At no time whisk. Whisking introduces air bubbles into the cream and that slows down incubation.
7. Place a blanket in your microwave (or oven). Microwaves and ovens are thermo-insulated and minimize the loss of heat.
8. Place the jars in the microwave on the blanket.
9. Loosely cover the jars with their lids or a towel.
10. Cover with and wrap around another blanket or a large towel. Make sure the blankets are covering the jars from all directions to minimize heat loss. This will make sure jars stay warm all throughout the incubation process.
11. Leave overnight (about 8 hours). Check if the Sour Cream has set (it should have) and if it hasn’t, leave it for a couple of more hours, and keep checking a couple of hours apart, until it sets.
    Note: Sour Cream has set if it separates somewhat cleanly from the sides of the jar when you tilt the jar. It should be firm at the top, while still being somewhat watery further down, but it should separate easily from the jar when tilted.
12. Move the Sour Cream to the fridge for at least 2 hours so it can properly firm up. Cooling the Sour Cream will help it thicken and improve its taste.
13. Enjoy!

Tips on Adjusting the Taste and Consistency of Sour Cream

You can easily adjust the thickness and the flavor of your sour cream to your liking by controlling the method and time of incubation.

To make sour cream with mild and sweet taste use the traditional mesophilic method. Simply bring your cream to 76°F / 24°C, add the starter, stir well until it dissolves and incubate at room temperature until it sets, for about 12–14 hours.

To make tart sour cream use the failproof heating method. First heat up the cream to just over 113°F / 45°C, then cool it down to 76°F / 24°C, add the starter, stir well until it dissolves and incubate at room temperature until it sets, and then for an additional 12–24 hours. The longer Sour Cream sits at room temperature, the tarter it will get.

For creamy more liquid sour cream, use the traditional mesophilic method to make the sour cream and stop it at the desired liquid consistency. Simply move it to the fridge when it is as liquid/thick as you’d like it. Then consume it fairly quickly because it will continue to gradually thicken in the fridge.

For super thick sour cream, incubate the sour cream until it fully sets (regardless of the incubation method) for about 12–14 hours, then move it to the fridge and leave it there for at least 2 days. Sour cream will continue to gradually thicken in the fridge.