How Long Do Marshmallows Last?
Unopened marshmallows keep 2–4 months in the pantry. Once opened, they stay soft for about 1 month if the bag is sealed tightly, and they can be frozen for 3–4 months.
Marshmallows — unopened
shelf life- Opened: 1 month in the pantry
- Homemade: 1–2 weeks in the pantry
Fridge at 40°F (4°C) or below · freezer at 0°F (−18°C). Freezer times are for best quality; frozen food stays safe longer.
Marshmallows are sugar syrup and gelatin whipped full of air and dusted with cornstarch. They are too sugary for bacteria to grow, so they rarely spoil in a safety sense. Their problem is moisture: left open to dry air they turn hard and stale, and in humid air they become sticky and fuse into a single lump.
How to store marshmallows
- Press the air out and seal the bag with a clip, or move the marshmallows to an airtight container; an open bag goes stale in days.
- Add a spoonful of powdered sugar or cornstarch to the bag and shake it if the marshmallows are starting to stick together.
- Freeze marshmallows in a freezer bag to keep them soft for the next camping trip. They thaw in about 10 minutes and do not freeze solid.
- Soften slightly stale marshmallows by sealing them in a bag with a slice of fresh bread for a day or two.
- Keep them away from heat; a bag stored above the stove or in a hot car melts into a solid mass.
How to tell if marshmallows have gone bad
- Hard, dry or crunchy marshmallows have gone stale. They are safe and still melt fine in hot chocolate or crispy rice treats.
- A sticky, wet surface or marshmallows fused into one block, caused by humidity or heat.
- Yellowing and a stale, off smell or taste in a very old bag.
- Any mold spots or insects in the bag, which are rare but mean the bag should be discarded.
Bacteria that cause food poisoning usually do not change the look, smell or taste of food. Go by the time limits first, and the signs above second.
Marshmallows shelf life chart
| State | Fridge | Freezer | Pantry |
|---|---|---|---|
| Unopened | Not recommended | 3–4 months | 2–4 months |
| Opened | Not recommended | 3–4 months | 1 month |
| Homemade | Not recommended | 2–3 months | 1–2 weeks |
| Store in an airtight container, dusted with powdered sugar and cornstarch. | |||
Not safe = perishable: no more than 2 hours at room temperature (1 hour above 90°F / 32°C). Not recommended = possible, but quality suffers or it serves no purpose.
Frequently asked questions
Do marshmallows go bad?
They go stale rather than dangerous. Marshmallows are mostly sugar, which keeps bacteria from growing, so an old bag is rarely a safety problem. Over a few months they harden, stick together and lose their vanilla flavor. Throw them out if they smell off, are discolored or show any mold.
Can you use marshmallows after the expiration date?
Yes, in most cases. The date is a best-quality date, and a sealed bag a few months past it is usually just firmer than fresh. Stale marshmallows still melt, so they work for hot chocolate, s'mores, fudge or crispy rice treats even when they are no longer pleasant to eat plain.
How do you soften hard marshmallows?
Seal them in a zip-top bag with a slice of fresh bread for a day or two, and they will draw moisture from the bread. For a quick fix, place the sealed bag in warm water for a minute, or microwave a few marshmallows next to a cup of water for about 10 seconds.
Can you freeze marshmallows?
Yes. Marshmallows freeze well for 3–4 months in a sealed freezer bag and are the best way to store an opened bag you will not finish within a month. They stay soft enough to separate while frozen and return to normal at room temperature within minutes.
Related foods
| Food | Fridge | Freezer | Pantry |
|---|---|---|---|
| Chocolate Unopened |
Not recommended | 1 year | 1 year |
| Candy Unopened, hard candy |
Not recommended | Not recommended | 1 year |
| Jello (Gelatin) Prepared |
7–10 days | Not recommended | Not safe |
| Breakfast Cereal Opened |
Not recommended | Not recommended | 2–3 months |
| Crackers Unopened |
Not recommended | 3–4 months | 8 months |
| Sugar Dry (uncooked) |
Not recommended | Not recommended | Indefinitely |
More sweets: Pudding.
Reviewed 2026-09-20. Times follow published USDA FoodKeeper / FSIS, FDA and CDC storage guidance; where sources differ we use the shorter time. How we compile this data.