I'm glad you bring up this point. It's a VERY common misconception out there. We're newer into the market so I can't say where it stemmed from but I'd assume a market guy and not an engineering guy (not knocking marketers
). We conducted specific testing to research the scorching issue that is everyone is so afraid of when it comes to single layer kettles. The results showed that scorching was not an issue. Our customers have also proved that it's not an issue since we've never had someone come back complaining about scorching. Also the 'holy grail' Blichmann kettles are only single layered.
The tri-bottoms are built with a little thicker side wall than us and Blichmann and obviously the thicker bottom. A 1mm side wall is plenty to hold up durability wise. The extra thickness just adds weight (in my opinion) since most people take great care of their equipment. For almost double the price of our kettles I just don't see them being worth the extra money. We used to (and still kind of do) offer them. But I always tell customers that I personally wouldn't buy a tri-bottom even if money wasn't an issue.
The only advantage of the tri-bottom is they can be used on a glass stove top as they sit perfectly flat and would conduct heat better.