I don't consider anything silly as whatever works for you is all that matters. We can all learn something new each day. I'd say it's rather impressive that the coffee shop could offer any extracting variables as those I've been in over the years seemed to know next to nothing beyond grinding, tamping and pushing a button. which I could taste it to better help, here are my thoughts: get a fresh dark roast and see if it comes out sour, not that you have to like the coffee but if it comes out sour on a dark roast then it's on the user end. What water are you using? try some purified water, not spring. run a "dummy shot" through the silvia make sure it's nice and hot, get a scale and place portafilter on top and press down to about 30lbs of pressure, then you'll know what it feels like to press down the correct amount. Thanks.
I didn't find the right solution from the Internet.
victorgrant replied
395 weeks ago