I went through a several month hiatus from espresso. At first it was just too much caffeine and I wanted to detox. Then it was just a temporary lack of interest. Anyway, I'm getting back into it and I want to make sure my equipment is in tip-top maintenance.
My main worry is that I left my Alexia sitting unused with water in the tank for several months.
First thing I did was replace the water in the reservoir and ran it through continuously with a few refills.

I've been using it for a few weeks now, but every now and then, I get a bad shot that tastes a little burnt/ashy. I've read that this is likely linked to scale.

I've read the article on checking for scale:
Checking an E61 Espresso Machine for Scale

Is there anywhere else in an E61 that scale could build up? I get the impression from that article that it would find buildup from typical usage as opposed to what I did to the machine.
I've had the machine for just over a year now and use filtered water. It might just be about that time anyway?

shawndo wrote:I've been using it for a few weeks now, but every now and then, I get a bad shot that tastes a little burnt/ashy. I've read that this is likely linked to scale.

Scale causing an ashy taste? Never heard that one before. A dirty grouphead is more likely. Have you backflushed regularly with Cleancaf/Cafiza/JoeGlo or equivalent?

HB wrote:Have you backflushed regularly with Cleancaf/Cafiza/JoeGlo or equivalent?

Yes, at least once a week. I did switch to the hippie "full circle" cleaner. I did not clean it during the several months that I didn't turn on the machine though.
I also pull the screen and gasket off and clean that once a week. Pallo brush and water (no detergent) backflush every day.
I only pull one espresso a day. maybe 2 if I screw up the first one.

Maybe ashy isn't the right word. Let's just go with a general "off-taste" I think I'm mainly looking for what I should look for in a machine sitting around for that long with water in the tank.

In that case, see Advice about bringing an espresso machine out of storage. In a nutshell, it's the same steps as a descaling, which for your espresso machine is very straightforward.

I think this is what I was half remembering.

Yearly
Descale your espresso machine once a year. No matter how good your water filtration may be, you're still getting calcium in your boiler tank. While small amounts of calcium won't alter the flavor of your espresso too much, over time that small amount will grow into a large amount causing a very bitter flavor in your cup and eventually causing damage to your machine.

Espresso Machine Cleaning - When and Why

I know ChrisCoffee is anti-descaling but it seems the consensus here is that descaling is ok. I think my first step is to buy some big wrenches, pull the mushroom thing and see how bad it is.

Well, the mushroom was completely clean. Still looked brand new. I guess I'll take a closer look at the grinder.

Or it could be the coffee.

It doesn't look like you don't need to descale if the mushroom is clean. Maybe the coffee is too fresh? It happened to me a few times when I couldn't wait to try out a particular coffee. Some need 7-9 days before tasting really good. If I try at 3 days post roast, I get ashiness. Just my theory though as there could've been other things going on with my setup.

You have it made - leave well enough alone and simply continue on with your (obviously working) maintenance adventures. You have one of, if not, the very best machines for straight espresso with expert service just 150 miles away.

Inspection of the mushroom showed zilch scale, so, DO NOT descale - don't ya think Chris' Coffee knows what they're saying and is balancing the pros and cons? I have descaled Anita twice in 6 years and the first time was for the photoshoot in that link previously provided. The second time - well - I don't even remember why.

Yeah, no intention to descale at this point. The mushroom looked like it was made of brushed steel instead of the pitted-chrome look I normally see in online photos.

I just cleaned the drive belt of my Versalab for the first time. Only one espresso on the cleaned belt, but there was a pronounced difference. I think the grind quality might have been slowly slipping and I didn't realize it. I didn't realize cleaning the belt might make that much of a difference.

Also, I know the argument about using beans too "young" but in my personal experience, it always seems that there is a bitterness that starts to appear at around day 6 or 7. Also, the few special shots that stick in memory that i've made have all been with beans 3-4 days old. I don't know if it's my technique/storage or maybe just my taste. I do have access to very good beans locally (Gimme, Intelli, Stumptown, Ecco, etc) It also seems that even the best espresso shops also use their beans on the young side.

Maybe i'll try glass storage instead of the airtight-steel jar that I have and see if that makes a difference.