The risk of espresso coffee machines

New Zealand Listener wrote:Many homes have an espresso coffee machine or the more recently introduced pod- or capsule-style brew-maker. That's all well and good, but some scientists are concerned at the potential for these machines to deliver more than coffee.

German researchers recently investigated whether metal contaminants such as lead and nickel were leaching from coffee machines into brews. They tested eight machines: three standard espresso makers, three coffee-pod and two coffee-capsule machines. All were tested for three days before and three days after decalcification.

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Some of this has been discussed before and I don't think there's anything that's a huge cause for concern, but descaling doesn't seem to be a good idea particularly if you have an older machine with a brass boiler.

We're all going to die of something. Descaling is common sense, and if done only as necessary, and flushed appropriately afterwards, than you really shouldn't be stressing it too much. There's so many more important things to worry about than possible water contamination via espresso machines. I hope when I die its with a double in one hand and my wife underneath me. You know....when they bury me, I mean....

What I always find worrying is that these sort of articles do mention that 'levels higher than recommended" of whatever are found, but they never examine for how long and what the total exposure is to whatever it is they examined and how that relates to havimg a real world life...(or how you can avoid 'dangerous levels" by flushing or washing out your boiler)
Think that the right conclusion is to avoid descaling and if you have to you'd need to flush your boiler good....duh.

Espresso machine design can impact the degree to which water can leach metals from the machine. For example, those who are not at all concerned about what their machine is doing to the water can be perfectly happy buying a DB with a large brew boiler; whereas those who wish to minimize the possibility can buy a HX machine with a very small heat exchanger.

I'm not particularly worried it about it myself owning a Linea Mini with a stainless boiler. And the more recent machines coming out of Europe are probably much better in terms of lead and nickel exposure given some recent regulations and use of lower lead brass and coatings such as Ruveco Tech. But I posted the article because I think it's good info for those who want to take easy steps to minimize exposure to toxic metals.

As with just about anything like this it comes down to dose and frequency of exposure. Daily use of an espresso machine certainly makes for regular exposure so it just seems wise to not descale an older machine regularly. The trend now anyway is just to use better quality (i.e. boiler safe) water which should eliminate the need for descaling.

FastGlass wrote: Descaling is common sense, and if done only as necessary, and flushed appropriately afterwards, than you really shouldn't be stressing it too much.

What makes sense is to use water that doesn't create scale in the boilers. Filling the boiler/s of a nice machine with an acid solution on a regular basis instead of dealing with the water makes no sense to me.

This is exactly the point: do not use water that will produce deposits, corrosion or leaching in the boiler or hot water-steam path. What can end up in the final output of the machine could be rather scary depending on the construction as not all brass is created the same and that goes for all the other metals. Buffered distilled water is the easy fix. Fresh RO water can be in an ionized state which is highly reactive and will dissolve all manner of metals.