I think you should let them operate their own equipment. You are kindly bringing them a few coffee samples to play with. Its personal and professional development, everybody wins, and apparently they are suitably thankful to you. However they need to operate the equipment they know, using their own barista techniques, especially if your samples are small enough that once you start trying to reconfigure the grinder between each batch, you could run out of coffee before getting it right. They are familiar with their set up and work place, and you arent...... I also dont see anything wrong with using the volumetric touch pads. They are nothing more than a volumetric stopper, which can be stopped early if you wish by simply pressing the button again when you want the flow to stop. That's it, nothing more. Also if you are a believer in "pre-infusion", note that while the machine's touchpad may be operating WITH pre infusion ON, if you bypass preset buttons and instead use the STAR (continuous flow) button on the touchpad OR the separate manual toggle switch provided on some brand machines, the pre-infusion will NOT operate. As I said, volumetric preset buttons are nothing more than pre programmed volumetric stoppers and just like "continuous flow" button OR manual toggle switches, can be stopped whenever you like by you simply pressing the button again....just like the continuous flow button.... Honestly guys, some of the things that get wrongly maligned in forums........ :🙂 I see your biggest problem being that you may not have enough quantity of each of your samples to get the grind just so for the best result of each sample, and I have exactly the same problem running out small samples from my sample roaster when there is a group of us that want to cup the beans. So.....man your weapons.....and enjoy the session!
