Most cultured cream sold in the United States is made from pasteurized cream. Federal law requires that milk and milk products sold in interstate commerce be pasteurized or made from pasteurized ingredients, with only narrow exceptions for certain aged cheeses. This means the cream is heat-treated before bacterial cultures are added to ferment it into products like sour cream or crème fraîche.
What Federal Law Requires
Under 21 CFR 1240.61, no milk or milk product in final package form for direct human consumption can be sold in interstate commerce unless it has been pasteurized or made entirely from pasteurized dairy ingredients. For cream with a fat content of 10% or more, the required pasteurization temperature is raised by 5°F beyond the standard thresholds. The two most common methods are batch pasteurization at 150°F (66°C) for 30 minutes and high-temperature short-time (HTST) pasteurization at 166°F (74°C) for 15 seconds.
Some states allow the sale of raw (unpasteurized) dairy products within their borders, so it is technically possible to find cultured cream made from raw cream at local farms or specialty shops. But any cultured cream you pick up at a regular grocery store has been pasteurized.
How Cultured Cream Is Actually Made
The process starts with pasteurizing fresh cream to kill harmful bacteria. After the cream cools, manufacturers add specific strains of lactic acid bacteria. These cultures convert lactose into lactic acid, which thickens the cream and gives it that characteristic tangy flavor. The drop in pH also makes the environment inhospitable to most pathogens, which is one reason fermented dairy has a long track record of safety.
This sequence matters: pasteurization comes first, then culturing. The cultures are deliberately chosen and introduced into a clean slate, rather than relying on whatever bacteria happened to be present in raw cream.
Crème Fraîche: A Notable Exception in Tradition
Traditional French crème fraîche is made from unpasteurized heavy cream that contains naturally occurring bacteria. Those native bacteria drive the fermentation, producing a rich, nutty flavor that fans of imported crème fraîche prize. In the U.S., however, most cream must be pasteurized before sale. American producers work around this by pasteurizing the cream first, then reintroducing safe bacterial strains to replicate the culturing process. The result is similar in texture and tanginess, though some tasters notice a difference in flavor complexity.
If you buy imported French crème fraîche from a specialty retailer, check the label. It may have been made from raw cream, which is permitted in France under a different regulatory framework.
Does Fermentation Replace Pasteurization?
Lactic acid fermentation does lower the pH enough to suppress the growth of many harmful bacteria. Research published in BioMed Research International notes that during fermentation, milk and curd can rapidly reach a pH where pathogens stop growing and their numbers decline as long as acidity stays low. This is why aged raw-milk cheeses have been granted an exception under U.S. law (they must be aged at least 60 days).
But fermentation alone isn’t considered a complete substitute for pasteurization in products like cultured cream, which are consumed fresh. The initial heat treatment eliminates pathogens up front, and the subsequent acidification provides an additional layer of safety. When contamination does occur in pasteurized cultured products, it’s typically traced to poor hygiene after pasteurization or equipment failure, not to a flaw in the pasteurization itself.
Post-Fermentation Heat Treatment
Some manufacturers add a second heat treatment after culturing is complete. Heating cultured cream to around 158°F (70°C) for 30 to 60 seconds kills the lactic acid bacteria along with any contaminants like yeasts and molds that may have entered during processing. This significantly extends shelf life but also eliminates any live cultures in the final product.
If you’re buying cultured cream specifically for its probiotic content, look for labels that say “contains live and active cultures.” Products that have been heat-treated after fermentation won’t carry that claim. Both versions started with pasteurized cream, but only the non-heat-treated version still has living bacteria when you eat it.
Shelf Life and Storage
Pasteurized cultured cream like sour cream keeps for about two weeks in the refrigerator when stored in its original, sealed container. Freezing is not recommended, as it breaks down the texture. Once opened, use it within the timeframe on the label and keep it cold. The lactic acid in cultured cream helps slow spoilage compared to plain cream, but it doesn’t make the product shelf-stable. If you notice mold, off-odors, or separation that doesn’t resolve with stirring, discard it.