There have been a lot of threads on when to stop the flush, and I have read through a bunch, but I still am not completely sure.

I have a grouphead thermocouple, and I am currently stopping the flush around 200F or so, take a look:



Sorry about the crappy angle, I was trying to get the temperature reading and the steam in the shot at the same time.

Here is a shot pulled after the flush to 200F

Let it blonde a little too far since it's tricky holding camera and making 'spro


Here's a pic of that shot:

Tasted good and it is very consistent, but I'm always looking to improve and it's my first time with an HX

Ilya, I would say off the cuff that the tiger flecking in the resultant shot indicate a brew temperature that's probably about right or a little hot. What it tasted like (burnt, sour, etc.) might help diagnose if the temperature is off, assuming you've got a coffee you know is great when it's pulling right.

Before anyone can help you with this beyond something like that, I think you need to show/tell us where the probe is located in the brew path. It's hard to tell from the info you've given. I also can't tell how the probe is reading during the shot, which is another key: you flush with a goal in mind, and that goal is getting the probe temperature to read out at the same thing over and over. You'll tune your flushing routine to that. Then you figure out how to modulate it. You'll need a Scace device or working taste buds to correlate what you see on the probe with too high or too low brew temp for a given coffee. Really the Scace can't help there, you just need taste buds. The Scace is nice to help you put a number down for your expected offset AND checking that consistency on your probe temperature is the same as consistency at the top of the puck. You may or may not get this, depending on where the probe sits. You can taste it too, if you don't have a Scace.

Anyway, if your probe never acts consistent during the shot regardless of flush regimen, or if it does but the Scace device shows big variation at the puck (or your shots taste all over the place, temp-wise), then you need to re-think probe placement or just give up and do your flushing by ear.

If your shots taste consistent and the readout is consistent, then you're ready to start working on modulating temperature by varying flush times. The probe will just show this effect to you as a number, which you'll have to verify when you taste the shots. Honestly, having had fun with this on the Elektra, I have to admit I'm not real sure how useful it is on these honking huge beast HXes. The Elektra's a dragon, though. What kind of recovery times are you seeing on the Astoria HX?

Here's the TC placement:



Recovery time is ridiculous I think it could make continuous shots all day long.

I have been using chestnut hill espresso blend and getting absolutely delicious espresso.

Today I picked up their yemen and am getting decent but not AS spectacular results. It isn't roasted for espresso and that's definitely a factor.. but I'm always up for trying different coffees

Since the TC is SOOO close to the water exit, I'm not sure a scace would do me any good.. what do you think?

Are you saying that the probe is placed just on the other side of the adapter? How far in does it go?

Anyway, that's actually a little further away than my Elektra probe:


Image from this post.

That was way too far away as I found when I got around to Scacing, as I described here. That's why I switched to a 36 gauge TC snaked into the group bell and placed essentially in between the bell and the dispersion block. I remember having to toy around a decent bit before I got the probe acting super-consistent. I'm not sure it was worth it; the flush routine was never a problem, always pretty much the same. Making the probe read that accurately was more work than it was worth per se, except that I had a decent bit of fun doing so and learned something new. That's what I know, and YMMV a whole lot, what with a differently designed machine.

After the adapter it goes in prob ~ 1.75" or so

I think you are right though.. it's not accuracy that's important but consistency.. basically make a shot at some temp, if you get good results use that same temp next time (or play up or down and see results)

But from the 1st video, does that seem ok based on the "water dance" ?

A few years ago when I made the first home grown cobbled together group head thermometer, I told people if you make one do not use it as an absolute. It is a reference point. If you flush till it reads 200, wait x seconds and pull your shot, and you like it. Next time flush to the same point for the same results. At the same time, if the thermometer is a bit wacky or the placement strange and you flush to 214, wait x seconds and pull good shots, then continuously flush to 214. It is simply a reference point for consistency, your taste buds will tell you if you have the temperature correct.