Is it my grind, brew pressure or some other factor?

[annp]

Ok, day two with Anita.

I've finally stopped staring, fascinated, at the underside of the bottomless portafilter long enough to look at the brew pressure gauge during a shot!

Anyway, here is my issue.

A double takes way longer than 28 seconds, about 37 seconds from initial lever operation to the beginning of blonde. I don't get 2 oz either.

That says to me, ok grind is too fine lets back off one click on Rocky.

I back off a click, and it's blonde and sour.

I've varied my dosing 1/2 a gram at a time down to 17 grams and up to 19 grams. 18 is optimal - the pour looks prettiest there.

My brew pressure is 10.3 during the shot. I back flushed with water yesterday after I went through a lot of coffee but I forgot to check the pressure during the flush. I'll need to check it again on Sunday.

My short sized long timed doubles taste ok, they are just itty bitty.

Is it a brew pressure thing?

Ann

[HB]

For Rocky, one click will add/subtract approximately five seconds of pour time, depending on the age of the coffee, moisture content, humidity, and phase of the moon (kidding about the last one ). You'll see a greater spread between detents the higher the pressure; in your case, ~10.5 bar is what Chris' Coffee sets as the maximum. Technically the maximum setting doesn't matter if you're pulling true doubles as the OPV / expansion valve will never open since the minimum pressure is determined by the puck (see Jim Schulman's Adjusting vibe pump pressure on HX machines for an explanation of the mechanics, including a nice diagram).

I recommend reducing your maximum brew pressure to 9.5 bar using a blind basket. The pressure will be slightly lower when pulling a ristretto. See Andreja Premium & Anita: Adjust brew pressure for instructions. The lower pressure will slow the pour down and also reduce the likelihood of channeling. If extraction problems continue, it may be time to get out the camera for some diagnosis. Or if you want to get fancy, it may be worth creating a video. Many digital cameras can capture AVI files that aren't obnoxiously large (]example from the Elektra A3).

PS: I noticed your pictures in the thread Anita is here and she is hot stuff! It is difficult to tell from the lighting, but the first in the series looks quite dark, suggesting overextraction (pressure too high) or too high temperature (rebound too long). That said, for day-two shots, they looked darn good.

[annp]

For Rocky, one click will add/subtract approximately five seconds of pour time, depending on the age of the coffee, moisture content, humidity, and phase of the moon....

I sure understand why stepless is much better with grinders. However, Rocky is here and unless he falls apart, he is sticking around. So I have to learn to check the moon phase on my calendar before I make coffee.

I recommend reducing your maximum brew pressure to 9.5 bar using a blind basket.

I had a nagging suspicious feeling that I was going to need to adjust that. Enough of one that I printed out Chris' instructions yesterday morning.

Question(s). Chris clearly states in the instructions that I need to unplug Anita before fiddling with brew pressure. I'm going to assume before I get to that point I plug her in, let her heat up as normal for 45 minutes, then unplug her, remove the case, make my adjustment and plug her back in to check.

When I plug her back in to check the brew adjustment results do I need to put the case back on her just to verify that the adjustment is correct? And how far do I turn? My instinct is to just turn a little teeny bit but if I'm over cautious we could be all night back and forth, plug and unplug, adjust and adjust some more!

I noticed your pictures... It is difficult to tell from the lighting, but the first in the series looks quite dark, suggesting overextraction (pressure too high) or too high temperature (rebound too long). That said, for day-two shots, they looked darn good.

A couple of factors for yesterday's photo session. Our kitchen is very dark with no windows and poor lighting. My initial photos had huge flash reflections off of Anita so I put a remote flash on a tripod and bounced it off the ceiling in order to get decent pics. Still, trying to make coffee and take photos means my attention is focused correctly on neither! And, while I totally agree about brew pressure, I might have waited a hair long after the cooling flush to get the shot going.

This morning I made an indecently large coffee to accomodate for the short pour, 3 triples in a huge cup as a cap and I was much faster on getting my shot started after the cooling flush. I kept thinking "Dan says not to dawdle."

I'll get a chance to play with brew pressure tonight, hopefully. Grr, have to go to work this morning.

I'll have to read on how to post pics on Home Barista. I don't think I can do movies because of the lighting issues - but my camera is quite capable of avi format if I can resolve that.

Thanks so much, Dan. I don't think I'd be as successful at this if you hadn't encouraged me with such good material - same goes for everyone here and on CG who has helped.

Ann

[HB]

Thanks for the update, sounds like your first days are going very smoothly. Now to your questions...

Let her heat up before brew pressure adjustment? Not necessary for brew pressure adjustments; of course, for brew temperature (pressurestat) adjustments, the machine must be hot.

Put the case back to verify the adjustment? Water, electricity, and exposed wires. How comfortable are you with working on appliances? Putting the case back assures you won't touch something you shouldn't. In other words, use your good judgement.

And how far do I turn? It's more than you think... about one bar per rotation for that expansion valve sounds familiar (sorry, it's been awhile).

A last piece of advice: Don't worry about using a lot of coffee in the beginning. It's easy to fall into the trap of economizing on coffee those first weeks; accept that you'll blow through coffee 4x faster for learning purposes.

[cannonfodder]

I can tell you from experience that adjusting your pstat before you power it up is much easier. There is a LOT of very hot parts in there. I made my adjustments cold, then power it up and let it heat to check the setting but Dan knows much more about it than I.

As far as the brew time, keep in mind that the preinfusion cycle on a E61 adds about 5 seconds to the brew time so a 30-35 pull is just about right (that has been my personal observation, please correct me if I am mistaken). Try a different blend of bean. Different blends will extract at different rates at the same grind setting. Beyond overdosing your PF there is not much more that you can do without a stepless grinder. As long as what you are getting tastes good, that is all that matters in the end.

[annp]

It was easy and it did the trick in terms of correcting my brew pressure from 10.3 to 9.5 bars.

There are a couple of tips that I'd like to offer.

I marked a flat of the 12mm adjuster on the expansion valve with a sharpie pen as a reference point because otherwise, how will you know you've turned it an entire revolution?

The silicon hose that plugs into the bottom of the expansion valve will need to be rearranged in the unit. If you just turn the expansion valve the hose will twist and bind. I had to cut the zip ties connecting the hoses together that go into the resevoir, redirect the hose and then replace the zip ties.

It took me about 3/4 a turn. Yes, I broke the rule and ran Anita with the case off because I originally turned the expansion valve 1 full turn which was too far - brew pressure got too low, had to turn it back to the right. I did power her down and unplug her before making adjustments.

Gee, my coffee is much better. I coarsened the grind by one step and increased the dose by 1/2 a gram. My shots run to the full 2 ounces in about 33 seconds without turning pale blonde and taste good. Nice crema!

Cool, Dan, thanks for the additional tips to Chris'.

Ann