I got an email off to Eric. Im, pretty, sure that the final production parameters were set up a couple months ago and they decided on Alu. They said they were testing both but I'm not sure they did. The Alu worked so well that they decided on it. I would have much preferred stainless, ceramic or glass. I got one coming to me in the first batch. I may even try to adapt the bowl. Maybe we can find a liner, kinda like the stainless MLB's, or something else. It seems people, like me, like to fidget with the Bndlstech products.