Setup: Crossland CC1, Breville Smart Grinder (newer model that does not need shim upgrade)
Bought some dark roast espresso beans from the local roaster; fresh roasted 4 days ago and very oily. Went to dial in the grind on the Breville and had nothing but problems! Grinder down to its finest setting and dosing anywhere from 18 - 20 grams (CC1 does not like overdosing) and getting 15 second extractions every time. Even tried up-dosing until I could barely lock in the portafilter and the extraction time did not change.
Went back to roaster and picked up a medium-dark roused (just short of 2nd crack) roasted on the same day as the previous beans, little to no oil on these guys. Put some in the grinder and immediately choked the machine. Had to dial it back 4 notches and resumed my usual 18g dose for a 27 second extraction.
Just wondering, has anyone had this major of a difference between roasts? Could it also be the oily beans messing with the extraction? Had something similar to this happen in the past but figured it was a fluke, but it happening again made me reconsider. Any tips?