JRising wrote:You might want continue to read more about how espresso machines work...

Thanks for the suggestions. Is it fair to say it's very difficult as a consumer to find out about all potential plastic use in these machines? I've done a fair bit of research on boiler material and the bigger tubing components of some of the machines I'm interested in, but it seems like it's nearly impossible to find out about subtle internal components like this. Are there any resources that would help that I'm missing?

Write emails to the links listed on the manufacturers' "Contact pages" on their websites and ask. They will respond truthfully, you'll get your info and they will get their chance to advertise at an interested consumer. If you know what features you want, you can surely narrow down your search to a dozen or fewer machines from 9 or fewer manufacturers.

JRising wrote:Write emails to the links listed on the manufacturers' "Contact pages"...

I've tried that and unfortunately never received a detailed reply back. Usually something to the effect of "all components pass safety tests." When I asked for a list of components carrying hot water or coffee they said to contact my local dealer, which I've done and have been told to contact the company haha.

I'd suggest trying to sample the water from the brew group before you buy. I was an all metal enthusiast when I bought my Pro 500.
There is definitely a metallic taste to the water similar to a grade school drinking fountain.

Interesting. Since the boiler is ss that's probably from copper pipes and/or the brass brew group? If so I can't imagine avoiding that in any machine.

The thing is, "plastic" doesn't mean much. There are dozens of plastics with various qualities, some good some bad. People just don't like it regardless.

It's like finding "metal" pipes... doesn't say much. they could be lead pipes or stainless.

baldheadracing wrote: The Rockets John mentions have no-burn steam wands - so there is (usually) PTFE tubing inside the steam and hot water wands for insulation.

The good news on "no burn" steam wands is that you can easily replace with a SS non insulated wand -- which I prefer anyway -- as I believe the steam is drier -- YMMV!

Again, even if you avoid plastic there's still almost guaranteed to be copper in the lines and that's bad for health.

Unless you run acid or contaminated water through it I never heard of copper tubing being toxic. What is the problem with copper would you say?

The "issue" with copper is the use of acidic water as mentioned, and/or the lead in the brass fittings used to join copper pipe, and/or the lead in the solder used to join copper with brass. The lead has been greatly reduced every decade since the turn of the century because the EU lowers their limits every ten years, the latest being the 2020 directive which comes into force December 1, 2023. (Dec 2003->20ug/l; Dec 2013->10ug/l; Dec 2023->5ug/l.)

The solution to the "issue" is to know the chemistry - at least the pH - of the water entering your espresso machine, avoid descaling, let a layer of copper(II) oxide form on copper surfaces, and, especially in older machines, let a bit of limescale form on the brass. Where limescale is not desirable, e.g., brass portafilters that have had the chrome coating wear off, lead passivation is fairly straightforward with household/drugstore chemicals.

In more general usage, copper pots and pans and serving vessels are almost always plated these days because one cannot assume people know when to use and not use copper in cooking and consuming.