Shelf Stable Foods
How long does ultra-pasteurized milk last in the fridge?
Unopened ultra-pasteurized milk holds 1–3 months in the fridge, but opening the carton starts an ordinary 7–10 day clock — date the carton the day you open it.
How long does it keep?
| Fridge | 1–3 months |
|---|---|
| Fridge, opened | 7–10 days |
Can it sit out?
Ultra-pasteurized milk is perishable — the FSIS 2-hour rule applies.
Perishable food left at room temperature for more than 2 hours should be thrown out — 1 hour if it’s 90°F or hotter (a picnic, a hot car, a summer kitchen).
How to tell if ultra-pasteurized milk has gone bad
- A yeasty or sour smell before it reaches the glass
- Milk thick enough to cling to the carton wall
- Flecks or curds caught in the pour
- A bitter, chalky taste
When in doubt, throw it out.
Keep it on a middle shelf rather than the door — the long unopened life comes from the heat treatment, and warm swings undo it fast once the seal is broken.
Quick answers
How long does ultra-pasteurized milk last in the fridge?
Unopened ultra-pasteurized milk holds 1–3 months in the fridge, but opening the carton starts an ordinary 7–10 day clock — date the carton the day you open it.
How long can ultra-pasteurized milk sit out?
The FSIS 2-hour rule applies to ultra-pasteurized milk. Perishable food left at room temperature for more than 2 hours should be thrown out — 1 hour if it’s 90°F or hotter (a picnic, a hot car, a summer kitchen).