How long do marshmallows last?
In the pantry, marshmallows keep for 1 year from the package date. Once opened, use it within 1 month.
1 year
from the package date
No guideline
1 month
in the fridge unless noted
Do marshmallows go bad?
Marshmallows are shelf stable, so the pantry time is about quality rather than safety: past it, flavour and texture fade before anything becomes unsafe. The date on the package is the maker's quality promise; the times here count from purchase unless marked "from the package date".
Two numbers to keep in mind: a fridge at 40 F (4 C) or below, and no more than 2 hours at room temperature (1 hour above 90 F / 32 C) for anything perishable.
How to tell marshmallows have gone bad
General signs for shelf stable foods, the group USDA lists marshmallows under.
- Crackers or cereal that have gone soft or stale, not crisp
- Rancid, paint-like smell from nuts, oils or nut butters
- Small insects or webbing inside a box or bag
- Spices that have lost their smell and colour
- Fermented or boozy smell from honey that has picked up moisture
More on shelf stable foods. The times above are quality guidelines, not safety limits; food that shows these signs goes out regardless of the date.
How long do other shelf stable foods last?
Source: USDA FSIS FoodKeeper dataset (public domain). How we decode the data.