Undrinkable Sour Shots - The Latest From A Neophyte

[ziemas]

The latest installment in the trials of a coffee neophyte......

I'm getting very nasty and sour shots out of my day old Pavoni Stradivari. From what I've read this is due to the water being too cold. although I have done all I can to raise the water temp. I've tried two different coffees, one a Colombian Supremo roasted on 29/8 and one a Sumatran roasted on 9/9, and I use a Pavoni Jolly grinder.



Here's what's I've been doing, please correct me or offer suggestions.


Fill machine with water and let preheat until green light comes on.

Bleed pressure via steam wand.

Wait for temp light to come back on.

Lift lever to heat group head and portafiltre. Repeat three times, warming cup with the hot water.

Insert portafiltre with coffee and raise lever. Wait about five seconds and lower lever slowly.

Wrinkle nose at sour coffee.


Thanks.

Z.

Also posted on CoffeeTimeUK. http://www.phpbber.com/phpbb/view...rum=coffetimeboard

[Nickk1066]

Have you measured the temperature of the water if you run a blank basket? I think it would be good to get some empirical data to back up your suspicions.

[ziemas]

I don't have a thermometer, but will pick one up when I go to the shops.

Although from all I've read after having the machine on for 45 minutes and running three shots I should be getting burnt coffee, not sour coffee......

[ziemas]

This is odd. I just ran a shot through my old Pavoni pump machine (it's been retired due to a nasty habit of shocking me) without letting it heat up properly and the shot wasn't nearly as sour as I'm getting from the lever machine, although I coffee was much cooler than what I get from the lever machine.

[timo888]

When the machine is ready to brew, can you describe the way the water emerges from the dispersion screen (without a PF in place)? Does it come out as a well-defined shower stream, or blustery and bubbling? Don't get your face too close

Also, how much pressure are you placing on the lever? Does it require some force to pull down, or pull down very easily?
Regards
T

[ziemas]

Thanks for the replies so far.

Without the PF the water comes out slightly bubbly for a brief moment (a second or less) and then is a well defined shower stream.

As for lever pressure I've tried with different grinds and tamps resulting in both easy to pull and nearly impossible to pull, all shots have been rather sour. The grind I'm using now is towards the finer side of things.

EDIT: I just tried a bit of a coarser grind and a quicker pull of the lever and got slightly better results. Testing has stopped for the moment due to massive caffeine over dosing over the last 24 hours.....

[ziemas]

Thanks for all the help! This morning I've managed to get drinkable shots. I tried three things to do this.

1) A new tamper. The original tamper is a bit small for the PF, so I sanded down a too large tamper for a perfect fit.

2) Lift the lever almost all the way up before inserting the PF so as not to disturb the grounds. I think this was the most important thing.

3) Pulling a shot and a half by doing the 'Fellini' move.


Now I can focus on getting better shots, not just drinkable ones.