Quickmill QM67 flow profiling upgrade - Page 2

#11: Post by **Marmot** » January 6th, 2022, 12:11 pm

I like to reduce the flow during the shot so it declines from 9 bar to about 5 at the end like on a spring lever machine.
I read that on the QM67 you can decide heating priority between coffee and steam boiler. Maybe on your machine it is set on the steam boiler?

January 6th, 2022, 12:16 pm

sambuist wrote:so it seems like you are doing a long low pressure infusion (20 sec to 1st drop). this is kind of a slayer shot i think. is it tasting better that without the flow control?

That's what I was aiming for the first shot. Shots have all tasted brighter. I'll go up a few more degrees on the brew boiler. Right now it's at 204.
On a positive note, shots have all been pretty. No spurts or gushes.

January 7th, 2022, 12:06 pm

Timer wasn't set and I have to leave so let's warm this up fast!

And as happens often, I run out of this batch of beans. Although I try and roast to the same level with my behmor, there's always a difference from roast to roast. Now to see what I need to do with this batch. I'm going to stick to the same slayer style extraction with the long preinfusion but won't go up to 9 bar the rest of the way. I'll go up to 6 the rest of the shot and see what I get.

January 7th, 2022, 1:18 pm

Marmot wrote:I like to reduce the flow during the shot so it declines from 9 bar to about 5 at the end like on a spring lever machine.
I read that on the QM67 you can decide heating priority between coffee and steam boiler. Maybe on your machine it is set on the steam boiler?

Yes, priority can be changed from brew and steam boilers. I left mine default with the brew boiler as priority. For the tests, I turned off the steam boiler. It's not a big issue. With my regular routine, there's enough time for the machine to recover between shots.

January 7th, 2022, 1:23 pm

Turns out I had enough beans in this batch for one more shot. I did a 20 second preinfusion and raised it up to 6 bar. Better results. Brightness tamed down a bit. Now to see if I'll get similar results with the new batch of beans.

My little bodum pavina. I prefer sipping from the nuova point cups though.

January 7th, 2022, 5:14 pm

Horrible angle. At least the pressure gauge is in focus. This shot turned out good. The brightness was toned down. Started low until drops showed up around 20 seconds. Didn't go to full 9 bar. Went up to 6 bar and tried to keep it there. As the shot progressed, I had to keep opening up the flow to keep it at 6 as it tried to keep going down. Was at full open at the end of the shot. Will get a better angle next time to show the device being opened/closed.

January 8th, 2022, 6:04 pm

Here's a video of the flow control device being manipulated during the shot. I was going for a lever machine profile with this shot. Preinfusion at 1 bar to start until the first drops showed. Had to slow the flow a bit as it tried to climb up a bit. Then shut it down for five seconds. Went to full and tried to slow the flow til the end of the shot. Shot was a bit bright. I'll try and grind tighter the next shot to see if it changes the flavor.

January 9th, 2022, 12:18 pm

This morning I went a little finer in the grind and the brightness in the shot went down. And because when trying to dial in a bean, you should change one parameter at a time, I'll go for three starting tomorrow! Going to make some rpavlis water, the potassium bicarbonate should be coming tomorrow. Also going to loosen the grind just a hair and change the temp too just to add to the variables

#19: Post by **sambuist** » January 9th, 2022, 7:30 pm

so just to add even more variables for you . you should try dumping as much water as possible until the puck shows beads on the portifilter and then dropping the pressure(flow) back to 2 or 3 bar for you the start of the shot.

this might help (it does for me) in getter a more even extracted puck. give it a go and see what you think

January 9th, 2022, 8:29 pm

I just saw a DE1 vid about that. It's a profile of a londinium shot? How is the rest of the shot? Same lever profile after the preinfusion? I'll try it out. But fine control with the device is something I'm working on.