Thermal Cups Comparison

Toby Keith needs to write another song because Yeti and a dozen other thermal-cup brands have made the red Solo cup do the “Boot Scootin’ Boogie” right out the door. Thermal cups have been around a long time, but Yeti made them popular last fall and, in a most unexpected miscalculation, ran out of them just before Christmas. That left room for Engel, Stanley, Thermos and others to snap up some market share. Is there a difference? Well, yes … and no, and for two reasons we felt a definitive test of these re-energized chalices was in order. First, we applaud the reuse of any container that eliminates the waste of plastic, cans or bottles. Second, we’re down with any old jug that can keep our refreshments refreshing all day long.

How We Tested
We acquired a variety of cups the old-fashioned way: We bought them at Bass Pro Shops, West Marine and a MarineMax dealer — the only dealer in Orlando, Florida, with a supply of the popular 20-ounce Yeti Rambler. All but one came with a lid — the Yeti 10-ounce Lowball. To keep things fair, we purchased an optional lid for it.

At 2 p.m. on a 75-degree day, we set our cups in the shade of a hardtop and filled each with ice, shaking the ice down until we barely closed the lids. Then we weighed the ice each contained and replaced it. Four hours later, we drained the melted water and weighed the remaining ice. We repeated the process again at eight hours. The dimensions of each container impacted ice capacity, even among containers of the same liquid capacity, so we decided to calculate and score on the percentage of remaining ice at each time of measurement.

Since these containers were also intended to keep hot things hot, we next filled them with 120-degree water from the tap. At four hours, we measured their temperatures and noted the percentage of temperature lost. We didn’t measure at eight hours because anybody who can’t drink coffee in four hours shouldn’t be bothering with it.

How We Scored
We calculated the average percentage of ice lost at each measurement point and then awarded points as follows:
Less than 15 percent lost ice at 4 hours = 3
Less than 25 percent lost ice at 8 hours = 3
Less than average lost ice at 4 hours (29 percent) and at 8 hours (50 percent) = 2
More than average lost ice at 4 hours (29 percent) and at 8 hours (50 percent) = 1

For the hot-drink test, we established an average score and awarded points as follows:
Retained more than 80 percent of heat = 3
Retained above-average (75 percent-plus) heat = 2
Retained average-or-below heat = 1

The exterior of a thermal container should remain at the ambient temperature and not transmit the temperature of its contents, so we awarded points based on how close the exterior temp was to the ambient temperature after three hours.