8-15 degree range!
Intra-shot!

Woah!

Ummm... yeah, that seems very wrong to me.
As some have pointed out - I have limited experience with home machines, but still...

Are you flushing and then building your shot (rebound method) or building your shot and the flushing (flush and go)?

I guess the pattern is flush - build - flush, which may be the problem. Typically the machine warms up a couple of hours. I do an initial 6 oz flush - 4 to quiet the water dance and 2 additional. I'm using a Versalab grinder and, grinding into the portafiler, it takes me 45 seconds to a minute to grind, distribute and tamp. By that time the water dance is back. The best stability I've got so far is to flush again - this time just until the dance ends. This usually starts me out around 205 degrees with a steady temperature drop of about eight degrees over the course of a 20 - 25 second pull. I have tried not doing the second flush, but typically we then start at 202 or 203 and climb 4 to 6 degrees.

malachi wrote:8-15 degree range!
intra-shot!

Woah!

Ummm... yeah, that seems very wrong to me.
As some have pointed out - I have limited experience with home machines, but still...

Are you flushing and then building your shot (rebound method) or building your shot and the flushing (flush and go)?

Try build, flush, pull shot.
See what you get then.
Then try flush, build, pull shot and see what you get.


If you don't get way better results... well... then something is wrong.

The flushing sequence is almost an art, each machine is little different just as each persons tastes are a little different. Unfortunately, there is no 'golden rule' to flushing. You just have to practice and make note of what you did so when you hit the sweet spot, you can reproduce it.

I do a big cooling flush after the initial heat up, about 10oz, then start my routine. I grind, flush, dose, flush, lock the PF in, dump the water out of my very hot cup and dry it, hold another 5 seconds and go. That put me right at 200f, hold another 5 and I get 201.5, no waiting after I dry my cup gets me around 198.

hperry wrote:The best stability I've got so far is to flush again - this time just until the dance ends.

Most mornings I move pretty leisurely behind the machine, so it's not unusual that I do a second "mini flush" before locking it. Not to get all Zen on you, but there's a definite intuition for the particular machine. An eight degree drop sounds like a lot, I would expect more like four degrees F. Let me toss out this idea: Let it rebound a second time, but only for 10 seconds. Remember that the HX is fairly small -- on the order of 110ml -- and easily exhausted. Specifically I'm proposing the slow man's routine:

1. Flush to usual brew temperature (~six ounces)
2. Leisurely prepare your basket in around a minute
3. Flush barely two ounces, just a teenie bit past the water dance end
4. Lock in the portafilter. Face towards Seattle and say a short prayer to the Espresso Gods (10 seconds have passed since step 3)
5. Go.

Oh, with all this flush minutia, I forgot to ask: How's the espresso taste?

With the Scace device I have to measure over a period of time rather than actually dosing because it has a flow restrictor that emulates the coffee. What I do discover is that there is an interval after the first flush (perhaps 40-50 seconds) where the temperature stays within 2 degrees plus or minus of a set point between 194 and 202 depending on how long you wait. I can get that at an interval after the first flush. However, after that I will get the ascending or descending pattern. I suspect that it has to do with the amount (or lack of it) of new water in the boiler whether the temperature climbs or descends. I appreciate you taking the time on this as I know this is very old territory for those of you who already have worked these things out.

malachi wrote:Try build, flush, pull shot.
See what you get then.
Then try flush, build, pull shot and see what you get.


If you don't get way better results... well... then something is wrong.

Thanks. An initial 8 oz flush takes me down to 180. It comes back to 194 and hovers within 2 degrees of that for a 20 second pull (seems to be optimum time with the Versalab grinder). Because I pull 2 shots for the second drink I cannot follow the same routine for the second shot because the machine has cooled down some. Seems probably I should be concentrating on the second shot - it appears that I can exercise more control on the first than I thought I could.

cannonfodder wrote:The flushing sequence is almost an art, each machine is little different just as each persons tastes are a little different. Unfortunately, there is no 'golden rule' to flushing. You just have to practice and make note of what you did so when you hit the sweet spot, you can reproduce it.

I do a big cooling flush after the initial heat up, about 10oz, then start my routine. I grind, flush, dose, flush, lock the PF in, dump the water out of my very hot cup and dry it, hold another 5 seconds and go. That put me right at 200f, hold another 5 and I get 201.5, no waiting after I dry my cup gets me around 198.

Dan,

Thanks! Your routine is very close to the timing I need. Dosing directly into the portafilter with the Versalab, distributing and tamping takes about a minute. Using your protocol I was able to keep things within about 2 degrees at approximately 198 +-1. I think I need to "edge" that up a couple of degrees. At that temperature the espresso is slightly sour.

I pull 2 ristretto shots using the double filter (about 1 oz) for my morning latte. After I get the first shot right (maybe a slightly shorter flush?) then I have to figure the second one out - at that point the machine has not been resting so the flush will be different.

The espresso? There are mornings when I'm really happy - and I achieve a really rich, sweet cup. More often than not I'm a bit on one side or the other of where I'd like it to be. I suspect ultimately a machine with temperature controlled in degrees fahrenheit is in my future. Over the last six months I've improved my tools and learned to manage many of the other variables (dosing, tamping, fresh coffee, grind) pretty well. I'm inclined to believe temperature is the major issue left to get more repeatable results.

Thanks for spending time going over what I know is old territory for you. It helped move things ahead. I really do like a good latte in the morning.

HB wrote:

hperry wrote:The best stability I've got so far is to flush again - this time just until the dance ends.

1. Flush to usual brew temperature (~six ounces)
2. Leisurely prepare your basket in around a minute
3. Flush barely two ounces, just a teenie bit past the water dance end
4. Lock in the portafilter. Face towards Seattle and say a short prayer to the Espresso Gods (10 seconds have passed since step 3)
5. Go.

Oh, with all this flush minutia, I forgot to ask: How's the espresso taste?

Well, looks like it was 1/2 of one and 6 of the other. My suspisions were confirmed that I had a heat issue. The more I thought about it, the more convinced I was that despite the boiler temp, the HX wasn't operating up to par. I descaled and everything seems hotter. Boiler flushes last longer, the group is hotter, and the flush and go tastes good again.

This particular machine has only been in service since Sept and my water hardness is 5 grains according to the test strips Chris included. Starting to think that they were wrong....Need to get a better test kit and a water softener.

Mike

I saw Jim's great video on his HX flushing technique. Thanks to him for it.

My question: does anyone know where I can get detailed instructions on how to attach a temperature sensor to my PF or my grouphead? I saw this in his video and I would really like the feedback so I can get the shot temperature right.

My machine in an Splendora Unica with an e61 type group.

I'm not very technical minded, I will probably need help to do this, but any detailed info about what kind of thermometer/sensor is needed and how to install/attach it would be much appreciated.

Thanks,
Danny