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See why.Thermal Food Jars
We tested six thermal food jars to see if any could keep their contents not only palatably hot or cold but also food-safe for several hours.
Published Mar. 1, 2015.
What You Need To Know
Thermal food jars are small, insulated, stainless-steel vessels that promise to keep food hot or cold on the go. We wondered if any could keep their contents not only palatably hot or cold but also food-safe for several hours since the U.S. Department of Agriculture discourages leaving cooked food between 40 and 140 degrees for more than 2 hours. So we filled six models (priced from $19.95 to $41.99) with a variety of prepared foods—200-degree tomato soup, 150-degree macaroni and cheese, and 38-degree tuna salad—and monitored the temperatures of the foods for 4 hours.
Discouragingly, only three vessels held the soup above 140 degrees for the duration of testing, and no jar kept the macaroni and cheese or tuna salad food-safe for even 2 hours, since the windows between their starting and food-safe temperatures were narrower. Some jars also lost points for durability, spilling when we shook them for 30 seconds and denting when we dropped them while they were in a backpack. Odors clung to the model with an internal plastic container.
If hot soup is all you transport, there was one model that will get the job done. It also cleans up in the dishwasher. But don’t expect any model to maintain food-safe temperatures for very long if its contents don’t start out very hot or very cold.
Everything We Tested
Not Recommended
- Cleanup: 2.5 stars out of 3.
- Durability: 3 stars out of 3.
- Cold Retention: 1 stars out of 3.
- Heat Retention: 2 stars out of 3.
Thanks to two layers of lids, each with its own twist seal, this sturdy 2-cup model kept tomato soup well above the food-safe 140-degree threshold for more than 4 hours. However, it failed to keep macaroni and cheese and tuna salad food-safe. It never dented or spilled, and it’s the only dishwasher-safe model we tested (its inner lid did fade slightly after seven cycles). The gasket absorbed more pungent smells like garlic, tomato, and turmeric but was easy to remove and cleaned up with a bit of scrubbing. It includes a spoon that folds and stores in its lid.
- Cleanup: 2.5 stars out of 3.
- Durability: 3 stars out of 3.
- Cold Retention: 1 stars out of 3.
- Heat Retention: 2 stars out of 3.
Though it didn’t insulate quite as well as the Thermos jar (and likewise failed to keep macaroni and cheese and tuna salad out of the food safety danger zone), this petite clone of the Stanley classic vessel kept soup well above 140 degrees for 4 hours. It was also durable and easy to clean, though it’s not dishwasher-safe and its gasket retained a very faint odor.
- Cleanup: 3 stars out of 3.
- Durability: 1 stars out of 3.
- Cold Retention: 1 stars out of 3.
- Heat Retention: 2 stars out of 3.
This roomy jar kept soup above 140 degrees for more than 4 hours, and its grippy cork lid was comfortable and easy to seal. It wasn’t dishwasher-safe, but it cleaned up well in the sink and didn’t retain odors. Durability is its weak point, as it dented after we dropped it to the ground while it was in a backpack three times. The manufacturer also recommends keeping it upright—surprisingly fussy for a product that should be able to travel in a lunch tote—but we shook it upside down for 30 seconds and had no soup spills.
- Cleanup: 2.5 stars out of 3.
- Durability: 2 stars out of 3.
- Cold Retention: 1 stars out of 3.
- Heat Retention: 1 stars out of 3.
Without the double-lid construction of its sibling vessel, this pared-down jar didn’t insulate food nearly as well as the other Thermos model, even after we preheated the jar with hot water. It isn’t dishwasher-safe, but it cleaned up well by hand, and it seals easily.
- Cleanup: 2 stars out of 3.
- Durability: 3 stars out of 3.
- Cold Retention: 0.5 stars out of 3.
- Heat Retention: 1 stars out of 3.
This wide, shallow jar posted the least impressive temperature retention numbers of the lineup (tuna salad was 67 degrees after 4 hours; tomato soup was 125 degrees), even after we preheated it by filling it with hot water per the manufacturer’s directions. It never dented, but its rubber gasket, which absorbed faint odors, was tucked up into the lid and hard to clean.
- Cleanup: 1 stars out of 3.
- Durability: 3 stars out of 3.
- Cold Retention: 1 stars out of 3.
- Heat Retention: 1 stars out of 3.
Though it insulated food about as well as the Lunchbots jar, this stainless steel–insulated column holds four plastic stacked containers, is more than 8 inches tall, and weighs 2 pounds—a cumbersome addition to any commuter’s load. Plus, without rubber gaskets to firmly seal, it’s no wonder that this jar failed to insulate its contents. Foods stained and odors very noticeably clung to the plastic containers. Durability was its only redeeming quality.
Reviews you can trust
Reviews you can trust
The mission of America’s Test Kitchen Reviews is to find the best equipment and ingredients for the home cook through rigorous, hands-on testing. We stand behind our winners so much that we even put our seal of approval on them.