I've got my Barista Express for a few weeks now and I've got some difficulty dialing in my shot time.
I use 18 grams off coffee in the non-perssurised double basket. I prepare my puck using a distributiontool and give it a consistent temp with the tamper. The grind size is dialed in to give a good pressure (needle at 1 o'clock). When I extract 2 oz / 56 grams of espresso, my extraction time from the first drip is 14-15 seconds. To lenghten the extraction time I tried adjusting my grind size to finer. The extraction time is longer but still under 20 seconds, and by do