What do you guys do? Knock the puck out then wipe? Or are you rinsing then drying too? I tend you have hot water running for a quick rinse and dry before reloading. I fear this might be lowering the portafilter temperature too much though. Not sure.

I flush the group head and use the water to rinse the PF, as well as cleaning off the group screen at the same time. That way, the PF isn't getting cooled off too much.

wipe

Ditto, wipe. Especially if you are not making a follow on shot.

The 2nd shot phenomenon, i.e. that the 2nd shot in a row was better than the first, had amateurs stumped. Most of us thought it was a problem with getting the brew path to a steady temperature. But even with the best of the new crop of double boilers or the fanciest of flushing regimes, the 2nd shot phenomenon persisted. It was a real mystery

Ian Eales cracked it last year; turns out it wasn't temperature, but coffee oils. The old SOP was to flush the group with a portafilter wriggle after making a shot. He recommended doing a backflush using a little ground coffee to dissolve the oils before starting a series of shots. I find wiping the group afterwards is more convenient and as effective.

In any case, this one is very easy to confirm for yourself. Flush the group old style after a shot, then wipe it. The towel or sponge will be covered in brewed coffee remains. Now, if you make a shot right away, these remains are still fresh, and taste acceptable, but imagine what happens after they've been baking on the group for an hour ...

With large intervals between one coffee and the next, I always clean immediately after pouring/drinking a coffee. The basket is always dry wiped before every reload.
I frequently take the basket out of the holder (not a naked one) to clean the basket's underside and the innards of the portafilter bell. Not doing this will dull the taste of the coffee.
Like Beezer, I would flush the grouphead into the portafilter and frequently brush the screen.
Given time-distance between shots, temperature would not be an issue.
In series, I would just wipe.

Regards
Peter

For me, one of the biggest benefits of a bottomless portafilter is rinsing it from the bottom between shots. I just turn the pump on and rinse, then wipe. Fast and easy.

Barry B

another_jim wrote:The 2nd shot phenomenon, i.e. that the 2nd shot in a row was better than the first, had amateurs stumped.

In a country that does not queue in a disciplined way (Italy), long time ago, I was surprised several times when an Italian client offered to let me go first, ordering caffè. Did not take long to figure out they were actually after the second shot. I must admit some malicious pleasure came over me when the barista moved to another group for that client when I had figured this out and the Italians were waiting to be second when I did not want to wait any longer.

another_jim wrote:Ian Eales cracked it last year; turns out it wasn't temperature, but coffee oils. The old SOP was to flush the group with a portafilter wriggle after making a shot. He recommended doing a backflush using a little ground coffee to dissolve the oils before starting a series of shots. I find wiping the group afterwards is more convenient and as effective.

I would say it is not just the oils behind the screen towards the pressure relief exhaust, but mainly the inside bottom of the portafilter.
Have you noticed some E/61 barista upon approaching the end of the shot move the switch/valve lever to the middle position (pump=off, back pressure valve=closed) - now the pressure over the coffee bed drops significantly and when pushing the lever all the way back, there is less backflush and less grounds/oils are sucked into the brew head through the screen.

Regards
Peter

I always clean everything after a session. Naked pf gets a rinse and the group gets the brush and a couple flushes. In my original question I was mostly concerned with what people are doing BETWEEN shots. So two shots or more obviously. And how those cleaning habits might affect brew temp.

Interesting about the oils. Ive experienced the phenomenon but didn't know why. I too put it down to temp stabilization.

Between shots, I use a dry paper towel to wipe the basket of my triple NP....I usually do just 2 shots, then froth the milk for cappuccini.

nixter wrote:I always clean everything after a session. Naked pf gets a rinse and the group gets the brush and a couple flushes.

Might not be good enough. After you finish, take a wet towel and scrub the shower screen, and see what you get.