Hi, Darcy's law as well as the Kozeny-Carman equation are effective descriptions (i.e. macroscopic). This means that both do not apply at smaller scales where the geometry of the medium becomes important. But that's where the fractal properties would show up. So it's probably nonsense. Regards, Jan

Well, I start getting worried about cleaning when grind retention goes up (I tend to weight before and after grinding), the grounds start to get clumpy or I change coffee. I would expect the critical part to clean is the space around the lower burr and from there down the chute. I was referring to t...

I cannot speak for the general case. But I explictly tried both with my vario two weeks ago (i.e. single dosing into the hopper and filling the hopper). I could not find a difference, not even for grind size, at least at the level of the vario's micro steps (at a generally fine setting). When the gr...

With all due respect, these baskets simply remove some of the problems when brewing espresso, home user or not, thereby exposing other problems that might not have been as prominent as with other baskets. That does not imply that the contrary is not true, of course: one might see problems with the V...

Hi Eric, do you have an estimate for the accuracy of your measurement? After having tried in vain with an 85mm lens and APC-C camera yesterday, today I took my 24-70mm, since it offers the highest magnification factor at 70mm at the cost of poor image quality to look at the 18g and the 22g (I don't ...

Ok folks, I know that this topic has been discussed many many times, but I am willing to believe that there is some truth behind the statement above. Some time ago in this thread "Imported Italian Espresso?" I got the following answer from Chris Tacy: And I really don't doubt that statement. However...

Hi James,the question to me is whether it would really make any sense to move to a ristretto with the same extraction. I'd expect, in order to get a balanced ristretto, you'd be forced to go near 18%. In that sense, it starts to make sense to imaging extraction as a path in the brew chart, evolving ...

Actually, the article states only that cumulative open area is relevant. Whether this is matched by changing hole number or hole size is not constrained, except for the holes not being too big to limit non dissolved solids. In the text it is really said that one should not change the dose at all. It...

Hi, I've read the article now several times and there's one point I simply don't get. The claim is made that the new filters should be used in a well defined way only, i.e. the dose in the filter is to determined by the volume of the coffee grounds in the filter before tamping. Then a statement is m...

That sounds great - I'll try it too on my next visit. Hotel Stein's Lounge (on the toop roof) is also worth a visit: {link} I don't remember the coffee, but it would be a sin not to try the Millirahmstrudel... Regards, Jan