DRG fans are mostly mollified and amused by this explanation, though there's still some grumbling about the steel molds argument (there are four mugs, but they clearly share the same mold).

Over the course of a week, that film can transform your mug into a petri dish of bacteria, mold, and other unwelcome guests.

Flip-top lids are often one piece and the most simple, so mold has nowhere to hide. The best flip-top travel mug we tried was the Miir Travel Tumbler. (We did love the S'well Commuter, but it's no ...