Posted Fri Jun 28, 2013, 10:16am Subject: Sour shots, help!
I've been reading this forum and tinkering with my Gaggia Classic for a few months now, but Iím still so far from a decent shot! Every one comes out sour. The nearest I can describe is Haribo Tangfastics Ė†eye-wateringly sharp.
Iím using Square Mile coffee and can make a lovely cup in my siphon brewer, so surely it comes down to the espresso machine or my technique?
Does anybody here have any experience with this problem? If so, how did you resolve it? All suggestions welcome, Iíll try anything! Although I canít stretch to a PID unless Iíve ruled everything else out!
I have tried the following:
ē Grinder upgrade (now with Eureka Mignon) ē OPV adjustment, now approx. 9 bar (down from 12 bar) ē Various temp surfing techniques, although no way of telling what temp I’m pulling at ē Hot water in the reservoir ē Grind/tamp combos (loose/hard; coarse/soft) ē Bottomless portafilter and 18g ridgeless VST basket
The beans Iím using are 8 days from roasting. Even near-choking the Gaggia doesnít seem to calm the sour, it just introduces a bitter taste on top. Yuck! But then, maybe thatís normal?
Sometimes I have time to let the machine warm up for an hour, other times just 10 minutes on the steam function (presumably thatís quicker?). Either way, I try to get the machine nice and hot to the touch before pulling a shot.
A few weeks ago I was attempting to imitate this video, based purely on timing and guess-work: https://www.youtube.com/watch?v=GFVTp4Jgo5k
The results were awful, presumably because I was shooting in the dark with regards to temperature. I found conventional temperature surfing (i.e. hitting brew when the light goes out) to be better, although not by much.
Do you think itís to do with intrashot temp stability?
1) clean the portafilter and group 2) check the temp (short flush into a styrofoam cup should allow comparison to other machines) 3) different coffee 4) 4 seconds of steam switch then 4 seconds off, then start shot 5) don't let the coffee sit in the machine - load and go 5) 2 ounce, 27 second shots 7) borrow another grinder for a day 8) different water
BB&B and you can use 20% off so cheap. Buy 2, so that you can take one apart. Many brands have the thermistor or wiring glued in and do not slip apart, so get the Polder.
For the second Polder, and surfing, this post. You take the thermometer apart. You may need to heat the steel probe to soften the plastic where it holds the probe. You can find a place to put the wire through the front or top and get the thermistor the boiler. Sometimes you can wedge it in a spot by an existing fastener, or try high temperature foil tape or glue.
Sorry, forgot a couple things. Hot water in the reservoir will harm the pump. It is meant for cool water, does not have high thermal limits or working temperatures.
Are you using a flush? Many machines work with best with a flush, in fact it is mandatory in some. Do not flush the Gaggia! The boiler is so small that your flush will cool the approximate 105 ml boiler water and ruin your shot, make it sour.
You need about 15 minutes minimum for the machine to stabilize with the PF locked in place. Surf only with the steam button or watching lights, not using flush. In the long thread about Gaggia temerature AndyPanda uses a non-stable method that is faster to warm up because it does not require stability, but a difficult method to learn. He describes it well if you choose that route. He anticipated temperature and in essence "became the PID."
NobbyR Senior Member Joined: 10 Jul 2011 Posts: 2,081 Location: Germany Expertise: I love coffee
Espresso: Poccino Opus One, Ariete Grinder: Eureka Mignon Istantaneo Vac Pot: N/A Drip: Melitta Linea Unica de Luxe Roaster: N/A
Posted Sat Jun 29, 2013, 1:41am Subject: Re: Sour shots, help!
Two possible reasons for espresso that tastes too sour are a brewing temperature that is too low, and a roast that is too light. The machine must heat up propperly, not only the boiler but also the brew group and the portafilter. 15 minutes with the portafilter locked in place is an absulute minimum for SBDUs, 30 for HX machines. Yours cups should be preheated as well.
*** "This drink of the Satan is so delicious that it would be a shame to leave it to the infidels." (Pope Clement VIII on coffee, when he was urged to ban the beverage)
Posted Sat Jun 29, 2013, 1:52am Subject: Re: Sour shots, help!
Thanks for all your comments and suggestions. So much to try!
Iím away from my machine until Monday but will look for a styrofoam cup and new coffee in the meantime. I have long suspected temperature to be the problem since many great coffees have been made with Square Mile beans. Iíll post an update soon with my progress/findings.
jonr Senior Member Joined: 25 Jun 2013 Posts: 315 Location: Americas Expertise: I love coffee
Posted Sat Jun 29, 2013, 5:53am Subject: Re: Sour shots, help!
IMO, a micro flush, just enough to make sure that there is no air in the boiler and that water is ready to flow is beneficial on a Gaggia. Do it after the boiler is hot, but then wait > 20 sec to let the boiler heat back up before doing the shot.
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