Espresso Machines & Copper - Page 3

#21: Post by **Rob101** » January 24th, 2022, 4:32 pm

Brass would be theoretically worse since it often includes lead to soften and make it workable

#22: Post by **Rob101** » January 24th, 2022, 4:37 pm

Brew Water does not sit in copper boiler. It goes through heat exchanger tube, it is constantly running and is almost always copper even on profitec machines

#23: Post by **Rob101** » January 24th, 2022, 4:47 pm

Also, has anyone actually checked the copper levels in the coffee/water from their espresso machine? apparently it's very easy to do. You can buy copper test kits for $20 at your local aquarium/pet store. Then presumably you would test copper levels coming out of brew group and then recheck by redoing a flush and running fresh water through the group an then another test on water coming from the water wand.

January 24th, 2022, 4:52 pm

Rob101 wrote:I think that the pint was missed. People are concerned with toxicity of boiler material on HX machines. The brew water never touches boiler material on HX machines. The brew water goes directly from tank through HX tube who is always copper even where boiler is stainless steel

To clarify, I was referring to the heat exchanger (tube) itself being made of stainless steel or brass.

Rob101 wrote:Show me one machine where a stainless HX tube is used. It's almost always copper even where boiler material is SS. Point is water in HX machine is always moving and fresh water brought is quickly heated. On dual boiler machines brew water is sitting in boiler. If copper level is a concern You can test this easily: go to nearest aquarium store and buy the copper test detection kits for $20

Of my HX's:
- Lapera - stainless steel HX, stainless steel boiler
- Elektra - brass HX, brass boiler
- Bezzera - brass HX (I believe), copper boiler with plating

Copper HX's would/should be popular with machines using E-61 groups with a thermosyphon for heating of the group. Fortunately, not all espresso machines use thermosyphons - or E-61 groups

.

Note copper test kits for aquariums do not have sufficient resolution IIRC. It would be like weighing out your espresso dose on a scale that only displayed kilograms. (An aquarium kit has about a 0.25ppm resolution. In comparison, my city water has 0.0011ppm.)

(I'll leave aside the debate on whether a heat exchanger must be cold-fed. Is a Victoria Arduino or Nuova Simonelli still an HX machine? Not according to their marketing ...)

#25: Post by **Rob101** » January 24th, 2022, 9:49 pm

So how can we confirm how much copper leaches from copper boiler HX machines? Is it the conclusion that because brew water contact with any copper parts in a HX machine is not long enough to be a concern? Does the hot temperature in the boiler accelerate the leaching? I would think that it should be pretty easy to test this. I would also think that given the popularity and long history of coffee drinking combined with the popularity and long history of copper use we would have answers this question by now. No?

#26: Post by **jgood** » January 24th, 2022, 10:33 pm

Does the Cafelat Robot have any copper in the water path ? If not, perhaps a good inexpensive option.

January 25th, 2022, 3:09 am

Rob101 wrote:So how can we confirm how much copper leaches from copper boiler HX machines? Is it the conclusion that because brew water contact with any copper parts in a HX machine is not long enough to be a concern? Does the hot temperature in the boiler accelerate the leaching? I would think that it should be pretty easy to test this. I would also think that given the popularity and long history of coffee drinking combined with the popularity and long history of copper use we would have answers this question by now. No?

Unfortunately, there are no specific answers (other than don't use unplated copper) as the chemistry of leaching is highly dependent on water chemistry. For example, acidic water leaches copper. This is why, for example, copper cookware use is pretty much restricted to certain foods like chocolate. Traditional non-plated copper cookware/kitchenware essentially isn't available anymore.

Commercial espresso machines can have copper because it is assumed that commercial installation and maintenance will ensure that the water is safe for use with copper. On the other hand, have a look inside espresso machines that are certified to domestic kitchen appliance standards like the Breville Dual Boiler. You probably won't see much copper inside.

#28: Post by **Rob101** » January 25th, 2022, 6:33 am

There's a lot of talk of copper boiler, but no one actually knows how much copper actually leaches. There shouldn't be any treason for not having specific answer. Considering that 99% of machines sold are with copper boilers, isn't this an important question? What if you have already invested in a machine with a copper boiler? Most water is not acidic unless it is stripped of minerals. There must be test kits available. This may not even be an issue. We're just speculating. It has been used for decades. Thanks it's a matter of chemistry do the answer should be easily attainable. And as I said, all machines have water running through coppper pipes, even those with stainless steel boilers? Also, isn't the issue with stainless steel that after a few years it will eventually rust in the inside? How will you even know if it is rusting?

#29: Post by **Rob101** » January 25th, 2022, 10:55 am

How about the fact that water is heated at high temps? Does that result in accelerated leaching? Has anyone completed their copper testing? Water quaility going into the machine should be easy to treat/maintain. And I think that copper poisoning is really the issue. The bigger issue is that copper accumulation over time has been linked to dementia

#30: Post by **cafeIKE** » January 25th, 2022, 11:11 am

Rob101 wrote:copper accumulation over time has been linked to dementia

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