Without a doubt, stainless steel, and here’s why. Aluminum products need to have a protective inner lining so that it doesn’t come into contact with food or beverages as they can emit toxic chemicals making it unsafe for us humans to consume what’s inside.
Aluminum bottles are most commonly lined with plastic resins or baked-on epoxy, which are both known to impart BPA and other harmful chemicals into the bottle. It also gets easily scratched exposing the aluminium underneath. Another material that is used to line aluminum bottles is ceramic and this actually cracks as it’s rigid, once again exposing the harmful aluminum underneath. So we’re sure you can see why we say that stainless steel is better and safer. All of these liners also make it difficult to get rid of tastes and flavors which means you’ll be tasting yesterday’s coffee with today’s tea!
This is why we are firm believers in our 18/8 stainless steel material that is completely safe for human use, non-toxic, and BPA-free. We’ve also designed them with rounded corners so no nasty germs and gunk can get stuck anywhere – they’re a dream to clean!