Glen wrote:That's due to declining pressure reducing overextraction of fines? And how about temperature? Is a declining temperature during extraction helpful in taming a conical burr that's being pushed to longer extractions?

All machines have declining pressure, on a pump the pressure declines as puck deteriorates and flow increases.

However the flowrate is more controllable and you can do very long PI. I had good results with like 15-20 seconds PI.

However I agree with Jeff conical like Niche are more challenging to achieve it with. But not the same as it cannot be done..

Ben Z. wrote:You seem to be incredibly confident in your assessment of the performance of various burrs. I take it you have a vast amount of hands-on experience?

Yes I owned and used more burrs then what is probably sane, and cupped them. But I always done it with mainly light roast so should always be seen in that context.

I owned anything from small hand conical to large conical grinders, from 54mm to 98mm flat burr grinders. And changing burr when ever something new came along was kinda my thing

A review (not mine) of Niche Duo