decent_espresso wrote:I'd like comment about Decent's non-metal tubing.
But maybe I misunderstood, and your worry is only about tubing after the boiler. In that case, it's true that Decent is non-metallic, but you'll find teflon tubing frequently on professional machines, especially on the steam path. Avoiding leakages due to thermal cycling, reducing calcification, as well as greater temperature stability, are the main reasons. Metal tubing will tend to lose more heat than teflon tubing, which is why teflon is often used on pro machines for the steam line.
John - having read a lot about the Decent machines, you're always very informative and transparent; thanks for the information. Yes, my concern is really about the path hot water takes from the boilers for brewing and steaming. It's actually a requirement from my wife that components in this path must be all metal. In the US, and likely numerous other countries, laws are lax regarding requirements for testing of new materials in food related applications. That's how (in general), things like PFOAs are used in teflon cookware for many years (I think until 2013), until independent testing determined that it is toxic and can cause serious pregnancy related problems.
I know Decent chose to use solid PTFE tubing and Ultem in the mixing chamber, and you guys feel confident in the safety of these materials based on the R&D you have put in. But how will they hold up over 10 years of use? Will there be zero migration of these materials into the water / steam? Will independent research at some point show that these materials can slowly migrate into hot water and accumulate in our bodies, causing undesired side effects? I do not know and it is not my intent to state these will be problems, but these are valid questions that would take time to answer. Part of this is certainly a fear of the unknown and, given alternative options, it is a risk we don't want to take. If these materials are used for 15 years and independent research over that time shows that, over time, they are completely safe, then we may reconsider...
All that being said, if you guys end up making a model that moved to all metal components in the hot water paths, I'll reconsider such a machine. I was extremely interested in the Decent machines and it would be at the top of my list if it wasn't for the teflon tubing (and possibly the Ultem mixing chamber).
Regarding the Bianca, I have some more research and reviews I'll have to go through to verify there are no non-replaceable non-metal parts in the hot water paths. I'm pretty sure I read there is some type of plastic tubing used in the steam path, I believe as insulation in the steam want, and that it is removable; if that is the case, then I'll need to confirm removing it doesn't cause any significant problems, perhaps other than a hotter to the touch steam want and a maybe a bit less steaming power.
HB - no problem about the reminder, and thanks for moving my post to a more appropriate forum.