Update: a barista at the shop on 5th told me my grinder is the problem, not my beans
I've been buying $19 bags of single origin for 6 months trying to fix a sour taste, and she watched me pour and said my cheap blade grinder is chopping the beans uneven. Now I'm staring at a $150 burr grinder wondering if she's right or just upsalling me. Anyone made that switch and actually tasted a difference?