[Homeroast] Sour espresso taste
mike.wilkens at gmail.com
Fri Jun 15 13:47:15 CDT 2012
Thanks again to all who have made suggestions. I can banish the sour taste (sour as in sour cream) by raising temperature. I get almost no crema with my shots, and I'm told I should see 50% or more crema by volume once the pull is finished. I tried fresh Brazil beans today, 2 days since roasted, and got almost zero crema.
John, I think you're right to bring up pressure. I'm told low pressure can cause less crema, and I understand that lever machines, which use less pressure are known for giving smoother shots with less crema. I spent a few hours experimenting with the OPV on the Gaggia, but no difference in taste or crema. Yes, I've done many experiments with the styrofoam cup! That's how I found out that pulling water was lowering the temperature significantly. That said: for all I know it could be low pressure and not low temperature that was "causing" the sour taste. There's more than one way to fix an issue, and espresso is sensitive to the combination of temperature and pressure.
Yesterday I decided to give up on espresso for now. Even when I can salvage a shot as a cappuccino, it has an unpleasant metallic-chemical taste that actually makes me feel a little sick, and sticks around as an aftertaste. The espresso, which is probably comparable to what you can get in most cafes, is really not enjoyable. I'm sure something is still wrong, but at this point it looks like a PID is necessary for brew temperature, and a pressure gauge is next. It seems like there's always another problem, another variable, another piece of equipment to buy with espresso.
I brewed the Brazil in the Aeropress, and it has a surprisingly good taste, delightful and different. I can get good coffee out of the espresso machine, but at its best it is a murky, muddy simulacrum of what I get in the Aeropress.
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