Well, what we’ve discovered in talking to our readers is that people are—apparently—infinitely curious about what to carry a beverage in. As the tumbler is the ultimate car-travel vessel, either during commutes or on road trips, we concluded that three hours of retention for heat and four for cold was plenty.

Klean Kanteen has since eliminated that 20-ounce size, though, and as of 2022 offers only 16-ounce and 8-ounce tumblers. The tumbler now comes with a closeable—though not completely leakproof—plastic lid to reduce the likelihood of spills. Zoku 3-in-1 Stainless Steel Tumbler: Our testers were really affected by the rounded—perhaps voluptuous—shape of this tumbler. Most brands have taken this into account; however, small, unattached parts may not be simple to disassemble and reassemble (and may have a tendency to disappear).A wider profile makes the stainless steel Yeti feel at home on a farm, at a construction site, or at camp. By hour four, the Corkcicle was the first to have its contents fully liquified, and the Coleman was on the verge.

The Rambler used to come with a standard lid—one you could actually fit a straw through—just like all the other tumblers. We don’t expect to go farther down that soggy road into lesser-known vessels—no goatskin botas or maté gourds (we hope)—but the idea of owning multiple means of avoiding landfill-clogging disposable bottles and cups is one we like. With the closest watering hole slightly out of range for a quick dip, we opted for a tried-and-true American classic instead: the 7-Eleven Slurpee.The tiny anti-glug hole in the Hydro Flask’s lid won’t let liquid slosh out when the tumbler’s in a cup holder, but you still can’t toss the tumbler into a backpack and expect no leaks. The packaging tends to emphasize that this one or that one keeps drinks “four times colder” or “colder longer. The stainless steel tumbler itself is very similar to our top pick, except for a slightly wider taper (it feels more like a pint glass) and a grippier color coating. At the time, the Hydro Flask had the slimmest, most covetable shape of all the tumblers we looked at and came in eight pleasing powder coats. However, the Hydro Flask’s performance and aesthetics—even after a redesign in 2022—make it the winner.

We spent an entire evening around a campfire with about 100 industry designers and professionals and asked many, many questions about their tumbler of choice. Pelican Travel Tumbler: This was a top performer in insulation, and we really liked the splash guard on this lid.Every 30 minutes for three hours, we measured the internal temperature with a digital probe thermometer.

The lid still nestles down into the cup, leaving the edge of the steel tumbler exposed; we didn’t notice any metallic taste, but if you don’t like drinking from metal tumblers, this might be a dealbreaker. The Hydro Flask took second place in our heat-retention test, bested by a single degree in temperature, so it will easily keep your coffee hot for the duration of your commute.On the ground at the summer Outdoor Retailer 2017 trade show, we stopped at every booth with a tumbler on display and received an in-depth rundown from the designers themselves, highlighting what made each model unique. The lid is easier to put on and take off than the Hydro Flask’s, thanks to its much larger thumb tab, and it closes with a pleasing softness.