I have never descaled my Alex, which I purchased new 5 years ago and have been using every day since then for a relatively modest 2 doubles per day (95% straight espresso shots, 5% steam use like cappa etc) plus a few extras on most weekends. Four years ago I did a water hardness measure and found it to be relatively soft at around 35-50 mg/l hardness, so I decided to run the machine off that soft tap water and left the descaling issue alone.
So imagine my terror the other day when I saw examples of scale buildup like this: HX-E61 with lots of scale on the mushroom, how should I descale the rest? or this:
Is there any way to (partially) descale a commercial espresso machine without pulling it apart?
I became worried that I may be heading for a tear down / rebuild project to remove the scale that must have accumulated over 5 years of use.
I was able to find several good descriptions of how to descale the machine:
Jim Schulman's Insanely Long Water FAQ. The title is intimidating but it is broken into sections and very helpful.
Simplified HX Descale (PourOver)
How to Descale a HX Machine Properly
However, before ordering Dezcal or citric acid powder, I wanted to be sure I wasn't going to ruin my machine. I believe that the issue of when/how often to descale an HX machine is not settled. Forum posters and others seem to recommend anywhere between descaling on a monthly basis, to 1-2 times per year, or never (according to Chris Nachtrieb, who sold me my Alex). This quote is from the most recent Alex user's manual at chriscoffee.com:
Chris Coffee Service wrote:Descaling is the process of running a descaling agent such as citric acid through the machine to remove the accumulation of mineral deposits.
- If you are using softened water then it should not be necessary to descale the machine.
- Often times descaling can cause more problems than it solves. It can react to the minerals and foam over ruining electrical components. If the solution is too strong it can cause the chrome plating inside the group to flake off and get in the coffee or if it‟s too weak it can dislodge minerals and cause a blockage. For liability reasons we strongly discourage descaling and will not provide any instructions on the process.
There are also forum posts on HB and elsewhere of strange noises and other problems after descaling, so to me there is not a clear answer on when descaling is recommended for a home user like me.
I needed a way to determine the extent of scaling in my machine.
One way would be to calculate from Jim Schulman's FAQ. Using his formulae I came up with a rough number of ~32 grams of scale buildup over the five years. (10.9 L / month * 49 mg/L scale * 60 months = 32 grams scale). This is five times the recommended level for when to scale -- his recommendation is to descale between 2.5 and 5 grams of scale buildup.
Another way to estimate scale buildup is from erics, who found a proxy for scale accumulation in E61 machines. The idea is to remove the plug at the top of the E61 grouphead and check for scale: Checking an E61 Espresso Machine for Scale. If the plug has significant scale, then it is likely the rest of the HX has scale as well.
So I found a suitable wrench and pulled the plug from my Alex, and this is how it looked:
So, here I am. I estimated 32 grams of scale buildup, but to me the grouphead plug looks fairly clean. So I am not certain about my next move.
Can anyone make a recommendation, to descale or not to descale?