Brew Pressure Mod on Gaggia Classic

#1: Post by **alex e** » February 16th, 2011, 8:43 pm

I opened a new bag of CC Toscano several days ago and man was I finally making some great espresso, then about half way through the bag about 2 days ago, I start getting blonde shots and minimal striping.

Shots start great and then BOOM, blonde, very early and suddenly. Harsh tasting too.

Wonder if I should adjust my brew pressure. Anyone done this?

#2: Post by **fwtechwiz** » February 17th, 2011, 6:05 am

Brew pressure is something that normally does not change by itself, unless something has gone very wrong. I would look first at possible causes of low pressure. First, have you done the SPV fix? Your SPV may be stuck open and venting some brew water back into your reservoir, thus reducing the brew pressure. Same thing with the 3way solenoid valve. It may be stuck open and venting brew water into the drip tray. I would start with a thorough cleaning/descaling of the 3way valve and if not already done, removing the SPV and plugging the fitting for it. Also before deciding that it's your brew pressure I would measure it to see where your at. If it's 9 bar or higher, it's not the problem. The Yahoo Gaggia group has detailed info on the SPV fix and 3 way solenoid valve maintenance. Hope this helps.

#3: Post by **dialydose** » February 17th, 2011, 8:57 am

alex e wrote: Wonder if I should adjust my brew pressure. Anyone done this?

Yes, I did it when I had a Classic. They should set it from the factory at 8-9 bars instead of 15 bars it usually is set at. It is a very worthwhile mod and will certainly improve your espresso (whether it is the issue you are having now or not). It doesn't cost a thing and take about 10 minutes. The tricky part is getting it set to the correct pressure. This is difficult to do without a scace so I recomend trying to borrow one from the yahoo group.

February 17th, 2011, 9:46 pm

This machine is only a few months old, though it was a refurb. I make one double from it daily. The shower screen was so clean when I removed it I decided to forego a backflush. I do clean my BPF and thoroughly wipe out all grounds left on showerscreen.

I have not touched the OPV.

#5: Post by **randytsuch** » February 18th, 2011, 12:05 am

I would at least backflush. I pull 2-3 shots a day, and do a water backflush when I am done for the day, and a chemical backflush every week or 2. Every week is probably overkill, but the water is always dirty when I do the chemical backflush.

Randy