...and we’ll post the answer on this blog. if you have a new machine and are disappointed with the results, start by weighing your coffee. 7 grams for a single shot, 14 grams for a double. Sure, you don’t need to do this once you have great coffee cascading from your espresso machine, but if you have tried everything else, it is worth going back to first principles. If you can not get that weight of coffee into your porta-filter, and tamped down say 3mm below the top of the porta-filter, then your grind is top coarse, and vice-versa if the measured amount drops in with space to spare. It sounds fanatical, but you will have to make adjustments for extreme weather conditions, particularly for changes in humidity and also as the coffee ages. For example, when you use Londinium Espresso you will most likely find you need to back the grind off (i.e. make it more coarse) initially. If you have it lying around for a while, just tweak the grind one increment finer. Remember to wait for any coffee that was ground at the earlier setting to pass through the grinder, before making it finer again if necessary. Hope this helps. Reiss.