Aarke
A cautionary example of steel-on-the-outside. The polished stainless shell reads as premium and plastic-free, but the water actually touches BPA-free plastic internals — the design language implies more than the materials deliver. Aarke isn't dishonest about it, but they lean on the look of steel to carry an impression they don't fully earn in the water path.
How clear are their specs?
You have to dig: the steel exterior is front-and-center, while the plastic water-contact parts surface mostly in spec sheets and support answers rather than the marketing. "BPA-free" stands in for a full material list.
Products we recommend
Carbonator 3
Aarke's mainstream carbonator ships with a PET bottle, but a dedicated stainless-steel "To-Go" bottle attaches and carbonates directly in its place - steel bottle, steel nozzle, silicone-only water path for well under half the Pro's price.
Carbonator Pro
The glass-bottle carbonator with the best water path - glass bottle, steel nozzle, silicone seals; the machine's enclosed steel chamber is what makes glass safe under pressure.
Products to avoid
Documented so you know what to skip — each still has a full breakdown and sources.
