You bought a carton of half and half two weeks ago, used it for a few mornings of coffee, and now it is sitting in the back of your fridge. The date on the carton has passed. You give it a sniff. It seems fine. So does half and half go bad, or are you worrying for nothing?
Does half and half go bad?
The short answer: Yes, half and half goes bad. An opened carton lasts 7 to 10 days in the refrigerator. Unopened regular half and half stays good for 1 to 2 weeks past the printed date, while ultra-pasteurized cartons can last 30 to 90 days unopened. Spoiled half and half smells sour, looks lumpy or curdled, or has turned yellowish.
For more on storing common dairy products, see the Food Storage Guide.
Key Takeaways
Opened half and half: use within 7 to 10 days
Unopened ultra-pasteurized carton: good for 30 to 90 days refrigerated
Individual UHT creamers (the tiny diner cups): shelf-stable, no fridge needed
Sour smell, yellow color, or lumps mean it is time to toss
Freezing is possible but changes texture; best for cooked applications only
How Long Does Half and Half Last?
Half and half shelf life depends on two things: whether the carton has been opened, and whether it is regular or ultra-pasteurized.
Nearly all carton half and half sold in US grocery stores today is ultra-pasteurized. That means it was heated to at least 280 degrees Fahrenheit for a minimum of two seconds, which kills far more bacteria than standard pasteurization. According to Cornell University, this process gives ultra-pasteurized dairy products a refrigerated shelf life of 30 to 90 days when unopened. That is why the date on your carton of half and half is often weeks or even months away at the time of purchase.
Once you open the carton, however, that advantage largely disappears. The product is now exposed to air and whatever bacteria live in your refrigerator. Land O’Lakes and most major producers recommend using half and half within 7 to 10 days of opening. Organic Valley, whose ultra-pasteurized half and half is widely available, recommends using it within 5 days of opening for best quality.
Type
Refrigerator (Unopened)
Refrigerator (Opened)
Freezer
Regular pasteurized half and half
1 to 2 weeks past printed date
7 to 10 days
Up to 3 months (texture changes)
Ultra-pasteurized half and half (most cartons)
30 to 90 days refrigerated
7 to 10 days (5 days per Organic Valley)
Up to 3 months (texture changes)
Individual UHT creamers (diner cups)
6+ months at room temperature
Use immediately once opened
Not recommended
How to Tell If Half and Half Has Gone Bad
Signs of Spoilage
Sour or rancid smell: Fresh half and half has a mild, creamy scent. A sharp sour smell means it has turned.
Lumpy or curdled texture: Healthy half and half is smooth and pours evenly. Visible chunks or a cottage-cheese-like appearance means spoilage.
Yellow or off-white color: Discoloration toward yellow is a reliable spoilage indicator.
Mold: Rare, but if you see it, discard the entire
