Buttermilk and sour cream: how long they keep, and what the freezer does
Updated
These two split the charts in opposite columns. For buttermilk the refrigerator times match and the freezer cells differ. For sour cream both charts say not to freeze it, and it is the refrigerator times that differ.
Clemson marks buttermilk’s freezer cell as not recommended, while Pacific Northwest Extension gives a time and adds that buttermilk will form curds when frozen. For sour cream, Pacific Northwest Extension gives a shorter refrigerator time than Clemson and says it will separate if frozen.
| Food | Refrigerator | Freezer |
|---|---|---|
| Buttermilk | 1–2 weeks | Not recommended Clemson HGIC3 months PNW 612 |
| Sour cream | 4 weeks Clemson HGIC2–3 weeks PNW 612 | Not recommended |
✓ 2 sources checked per row A single figure means both charts print the same time. Red cells show each chart’s figure where they differ; we do not average them.
- Clemson Cooperative Extension, Home & Garden Information Center, Food Storage: Refrigerator & Freezer (HGIC 3522) (revised March 31, 2020) — verified 2026-09-27
- Pacific Northwest Extension (University of Idaho, Oregon State University, Washington State University), Storing Food for Safety and Quality (PNW 612) (revised March 2023), Table 2, p. 12; Table 2, p. 13 — verified 2026-09-27
Good to know
- The reasons Pacific Northwest Extension prints are about texture: curds in buttermilk, separation in sour cream. Clemson’s footnote for its asterisk only says “safety or quality issues” and does not say which one applies to these two.
- Pacific Northwest Extension tells you to check the carton date on buttermilk and says it will keep several days after that date. Clemson’s buttermilk line has no date note.
- Pacific Northwest Extension lists sour cream dips, commercial and homemade, on their own lines, both not recommended for the freezer. Clemson has no matching line, so they are left off this page.
Out of buttermilk for a recipe? What stands in for buttermilk.
Both charts give these times for best quality and call them guidelines, not hard limits. How the rows are matched: our method. Spotted a row that does not match its chart? Tell us and we will recheck the original.