Happy to report that my Expobar Office Lever Plus is working after a small hiccup with a loose wire (presumably from shipping). Now for the question, which I am certain that has been posted before, but I couldn't figure out how to search? My shots are very sour. I think that is the correct description. They taste as if the beans are green. Perhaps a general guideline can be given for my particular machine and grinder. Expobar Office Lever Plus and Baratza Vario.