Best Insulated Food Containers From Our Tests

An insulated food container stacks the odds more in your favor because it’s designed to retain hot and cold temperatures for longer. But as CR discovered when testing eight insulated jars in our labs, they’re only as good as their ability to retain temperatures and not leak chicken soup all over your bag. We tested some of the things you might be concerned about when carrying an insulated food container around town—including insulation and leaks, and how well a jar can eliminate the lingering smell of chili (talk about a challenge). We even performed a drop test, and we’re happy to report that all the containers survived. We learned that no single jar is perfect, but four rose above the rest.

Some insulated jars come with specific claims about how long they can be relied on to maintain consistently hot or cold temperatures. Tracking temperatures is important, not just because you want to enjoy your meal at a reasonably warm or cold temperature, but because the Department of Agriculture says that keeping hot food at or above 140° F can prevent it from developing bacteria and falling into the “danger zone.” Keeping cold food at or below 40° F is also recommended to help prevent bacterial growth. 

Pro tip: When using insulated containers, it’s common practice to add and then remove boiling water from them before filling them with hot foods, and ice water before filling them with cold foods. CR did this before each test to help boost their ability to retain temperatures longer. We then tested each jar with two hot foods (chili and chicken soup) and two cold foods (chicken salad and fruit).