HX flush - with last puck in place

[RegulatorJohnson]

what do you guys think about doing your cooling flush with the last puck in place.

i just let in go into the drained drip tray then rinse it out and the end of the session.

i have done it 3 times and it seems to be a nice blend between a pure backflush and an un-resisted flush.

and it sort of simulates pulling a shot but you dont use the beans but you get the benefit of cooling. woohoo!!
thanks for the time.
bye now.

jon

[HB]

what do you guys think about doing your cooling flush with the last puck in place.

Is the idea to slow down the cooling flush? I used your "blind flush" with good results on the Vibiemme (excerpted below), but hesitate to flush steam and scalding hot water through a spent puck. It just seems, well... icky.

it seems like i get a more accurate reading this way because by the time the display reads 200° that water has passed and i really have something probably cooler. if i backflush i can simulate a shot which is what these machines are meant to do... make shots. not flush 6-8 ounces of water.

i do this until the pump hits full pressure then +3 seconds. wait 10 seconds and repeat until the temp, when the pump hits full pressure, is 4° above where i want the brew temp to be... ie 202° will yield a 198° brew temp. then i can brew immediately or up to about 30 seconds and get that temp. a quick normal flush to verify the temp will work as well.

the temps seem to be more stable. than a traditional flush.

i only use the back flush on the first shot after a long idle. but it will work for any shot.

[luca]

I noticed that brewing a few shots seems to stabilise the temperature on some HX machines in a way that a flush didn't. I took a spare blind and punched a small hole in it with a nail and am using that for the "blind flush" thing. The obvious benefit of this is that it doesn't use coffee and it's a helluva lot cleaner than flushing through a spent puck. In fact, the "blind flush" often removes a lot of gunk. I really ought to grab a scace back and check this whole thing out again, though. I do also think that we need a better name for this than "pressurised portafilter" ;P

[RegulatorJohnson]

i guess my goal is to get to brewing temp by wasting as little coffee and water as possible.

i was thinking a straight flush goes too fast and the blind flush simulated shot is too slow and not really exactly like pulling a shot. so i wanted something closer to a simulated shot. what can i put in there instead of coffee to restrict the flow to near coffee like parameters. hmmm maybe a sponge? no. maybe a hole in a blind basket? nope only have one. hmm what is just like coffee but not really like coffee. what do i have easy access to? old pucks!!! so i gave it a shot...pun intended.

i realized the nasty-ness factor of this practice but its not really that nasty, is it? aren't we really just talking about an extremely overextracted shot. i wanted an opinion on it. but i do not do this all the time. i just wanted to try to get closer to simulating an actual shot.

IMO a spouted PF is nastier because the actual shot you are planning on consuming, is touching that build up of gunk in the spouts and the bottom of the PF. eww.

jon

[SLC]

Now I have to get another blind basket and put a hole in it and use that as a flushing method to get the machine to temp and should clean out the group head rather well. Great idea. IMHO when a spouted PF is clean then there is not an issue of "gunk" and it is very easy to keep clean. The pour does not seem as violent on its way to the cup for whatever that is worth. Now we need to get a few more blind baskets in SLC....

[HB]

Now we need to get a few more blind baskets in SLC....

Or just cut a dense sponge the size of a puck and stuff it in an extra basket. That's what I did in my pre-Thermofilter days to measure brew temperature at the grouphead.

[Sedi]

I have an Oscar. NS states it has a "patented mechanical preinfusion". Once I suspected it is just a chamber similar to an E61, but I dont really know. One thing I know for sure is that for the past year I had this machine the preinfusion wasn't plug and play for me. If I don't apply some back pressure during the flush the preinfusion for the first shot takes too long and the shot is a lot worse than if I did. I became sure of this since when pulling shots in a row it doesn't happen, that is, preinfusion is consistent and short. As soon as I flush some water through the group it gets me back to the stating point, and first pull after that has a rather long preinfusion, longer than 11s, that burns the shot. I recently verified this observation with another Oscar user. I usually use some preground coffee I have from old beans and bad roasts for that purpose. I thought a lot about using a blind basket with a small hole instead but never did it.

Anyway, I think that using such a device gives more consistency not only in temp but also in starting conditions for preinfusion and for the rest of the pluming, and it might be true also for E61 machines, although I have no experience with this method and such machines that verifies this.