THERMOS FUNTAINER Food Jar Review: A Lunchbox Bestseller for a Reason

A food jar only has one job — keep lunch at a safe, appetizing temperature for a few hours — and this is the one that consistently gets recommended by parents for actually doing it.

Who it's for

This is built for parents packing hot lunches — soups, pasta, leftovers — for school or daycare, where the food needs to stay appetizing for several hours without a microwave available. If your child's lunches are mostly cold items (sandwiches, fruit, snacks), a simpler insulated container without the pre-warming step will be less hassle day to day.

What we liked

• Keeps food genuinely hot (soup, pasta, leftovers) through a typical school day, not just warm.
• Wide mouth with included spoon makes it easy for younger kids to eat from directly.
• Stainless steel interior doesn't retain odors or stains the way some plastic containers do over time.

What could be better

• Needs to be pre-warmed with hot water for a few minutes before filling to get the best heat retention — an easy step to forget.
• The lid has more parts to hand-wash than a simple screw-top container.

Key specs, explained

10 oz capacity is sized for a single kid-portion serving rather than an adult meal — plan accordingly if you're packing for an older child or an adult with a bigger appetite. Vacuum-insulated stainless steel is what allows the jar to hold heat for hours rather than the 30-60 minutes a basic insulated plastic container manages, since the vacuum layer (rather than just insulating foam) is significantly more effective at slowing heat transfer. Wide mouth opening with included spoon is specifically designed around a young child eating independently — a narrower opening common on adult thermoses would make self-feeding much harder for smaller hands.

Frequently asked questions

Q: Do I really need to pre-warm it with hot water first? Yes, this step meaningfully improves heat retention — filling the empty jar with boiling water for a few minutes before adding the actual food warms the jar's interior mass, so it doesn't pull heat out of the food itself during the first stretch after filling.

Q: How long does food actually stay hot? With proper pre-warming, most parents report food staying hot enough to eat comfortably for 4-6 hours, which covers a typical school day between packing at home and lunchtime.

Q: Is the FUNTAINER dishwasher safe? The jar body is generally dishwasher safe, but the lid has more components (gasket, spout, or vent depending on the specific lid style) that are often recommended for hand-washing to avoid degrading the seal over time — check the specific care instructions included with the product.

Should you buy it?

For hot lunches especially, this is one of the few kids' food jars that reliably delivers food that's still actually hot by midday.

Check price on Amazon