So after watching Lance Hedricks latest video on how to brew espresso. He kept emphasising that medium to dark roasts should be under 90 degrees c. … I was already getting good tasting shots with my medium roast at 93deg on my Rancilio Silvia pro X that had nice body and sweetness. So I decided to try and reduce the temp to 88/89deg c.
Much less body , too much acidity. Looked under extracted. So this caused me to grind finer. And made the shot worse. Lance always harping on about grinding coarser is better, but then saying lower temp is better as well . Yet lowering the temp caused too much brightness forcing me to grind finer.
So I went back to 93 degrees and back to the courser grind and shot tastes good now.
Either my Rancilios PID is not calibrated properly or Lance giving poor info in his videos.