He bought it just two years later? 1989 to 1991 seems quick for the fad to die off before he proved it wrong lol.

I mean 200 to 5000 is a big jump but how much of that is just the algorithm liking comments over tags right now? Feels like the same advice gets recycled every few months with a new label. Not saying it doesn't work, just seems early to call it a rule.

Yo hold on, I gotta disagree with the idea that this makes a burr grinder pointless. Sorting by hand only pulls out the worst stuff, it can't fix the fact that every particle is still a different size, which is what actually causes the uneven brew. A good burr grinder gives you a tight range of sizes so everything extracts at the same rate, and no amount of shaking in a jar lid gets you there because you're just removing extremes, not making the middle consistent. That said, if it's making your cups taste sweet and clear for two weeks straight, keep doing it, results don't lie. I'd just say a burr grinder wouldn't make the step pointless, it would make it way less needed.