@renagde , do you ever screw around with the pre infusion time and start/stop feature of the Bambino?
I almost always make an Americano in the morning. With some of my home roasted coffee, it kept coming out too sour. I tried changing grind, dose, and running a higher volume shot, but nothing worked. I always run it in manual mode to stretch the pre infusion as long as possible.
I decided to try multiple pre infusions since the machine only allows you to go to 10s. I'd run it in manual and stop the machine at 9s pre infusion, then immediately repeat. I repeated until I got first drops and then let it ramp up pressure. I think it was about 20s or so of pre infusion. Ran it to 32-33g, shut it off, and let it continue to depressurize until it hit 40g and pulled it.
Holy moly what a difference. My Americano was perfect. No sourness, no bitterness, only sweetness.
After learning a bit about the mechanics of the machine, you can do a whole lot more types of manual shots with it than most people realize. Hopefully I don't break it haha