Sour Cream & Crème Fraîche FAQ

Thinking of making sour cream or creme fraiche at home? Learn more about each cultured dairy product and what is involved in culturing each at home with our comprehensive FAQ. If you're still unsure how to get started, don't hesitate to reach out, we are happy to help!


Q. What is the difference between sour cream & crème fraîche?

A. Sour Cream is a cultured cream product that contains about 20% butterfat and has a sour flavor. Crème Fraîche is a cultured cream product with more butterfat and a milder flavor.


Q. What cultures do you have for making sour cream?

A. Our Cultured Buttermilk Starter and Buttermilk & Sour Cream Direct Set Starter Culture can both be used to culture sour cream.


Q. Are there other ways to culture sour cream?

A. Real sour cream requires the specific culture. A substitute and very good-tasting soured cream can be made using yogurt or kefir as starter instead, but it's not really what we think of as sour cream. You can find details in our How to Make Sour Cream article


Q. How do you culture Crème Fraîche?

A. Crème Fraîche can be easily cultured using our Crème Fraîche Starter Culture or with a direct-set aromatic cheese starter culture such as flora danica or mesophilic aromatic type B. You can find details in our How to Make Crème Fraîche article.


Q. How long will the Sour Cream and Crème Fraîche starter cultures last if unopened? What do I do with extra packets?

A. Extra packets of starter culture may be stored in the refrigerator or freezer. Information on how long each type of culture lasts may be found in our article How Long Will Your Culture Last.


Q. What ingredients are in the starter cultures?

A. Ingredients for every culture we carry are found on each product page.

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Q. What kind of cream can I use?

A. Any type of raw or pasteurized dairy cream can be used with direct-set and heirloom starters. Avoid ultra-pasteurized dairy cream.


Q. Can I use raw cream with these cultures?

A. Yes, raw cream may be used. Note that raw cream will yield a thinner sour cream or crème fraîche. Complete instructions on How to Make Raw Sour Cream can be found on our website.


Q. Why can’t I use ultra-pasteurized/UHT cream for culturing sour cream or crème fraîche?

A. Cream that is “too clean,” such as ultra-pasteurized/UHT cream, or cream that has been heated by microwave, may be too sterile for the culture to use as nourishment.


Q. Why can’t I reculture a direct-set starter?

A. Direct-set starters are one-time-use cultures. When culturing cream, they generally cannot be perpetuated beyond the initial batch.


Q. How can the sour cream starter culture also make buttermilk?

A. The bacteria in the Buttermilk & Sour Cream Starter when added to milk produce a cultured buttermilk. By adding the same bacteria to cream, the culture produces sour cream.


Q. Can I use the Cultured Buttermilk Starter to make sour cream?

A. Yes, first you must culture a batch of buttermilk using the starter. Then the cultured buttermilk can be used as starter culture to produce sour cream. Instructions for Making Sour Cream, with details for using cultured buttermilk along with other options, are available on our website.


Q. My house is colder than 70ºF, how can I culture sour cream or crème fraîche?

A. Many homes maintain temperatures that are cooler, especially in the winter. In our article, Cold Weather Care for Starter Cultures, find out how to keep your cultures the perfect culturing temperature.


Q. How important is  temperature when culturing?

A. The temperature can vary within a certain range specified in the instructions, but it is very important to stay within that range. Too warm and the bacteria will die. Too cool and the culturing will halt, and will likely not start again.


Q. How will I know when my sour cream or crème fraîche has set?

A. Once it has set it will be more or less uniform in appearance: one solid mass. It should appear relatively smooth. Sometimes a bit of whey will separate during the culturing process. This is completely normal.


Q. Why is store-bought sour cream thicker than homemade sour cream?

A. Store-bought sour cream generally contains thickeners. To thicken homemade sour cream, add a bit of dry milk powder or heat the cream to 180ºF and hold for 30 minutes. Cool completely before adding the starter culture.


Q. Are there differences when culturing at high altitudes?

A. Making sour cream or crème fraîche at high altitudes causes it to set faster. Culturing overnight might not be wise.


Q. How long will finished sour cream or crème fraîche last in my refrigerator?

A. In the refrigerator (40° to 45°F): 1-2 weeks