Flair Pro 2: 12.5 microns vs 22 microns?

Recommendations for buyers and upgraders from the site's members.

#1: Post by methylxanthine »

I've narrowed my choice of grinders down to either the k-plus or the jx-pro. on a manual lever like the flair pro 2 (or maybe the la pavoni which i'm condering down the line), will the uncertainties in my hand pressure outweigh any differences that could be gotten down at 12.5 microns, or will i still notice the differences in all the parameters that matter (drawdown times, acidity, etc)? ergonomically i do prefer the k-plus but i don't mind giving up the conveniences in that respect if 22 microns isn't quite sufficient to allow me room to play in terms of said parameters.


#2: Post by Pressino »

I'm not really sure, but I think that the grind step difference might be more significant for flat rather than conical burr grinders, given that flats are more unimodal, and especially for espresso very small changes, like just one notch on the Mazzer Mini or SJ grind adjustment collar, can make a huge difference in the cup. I think each notch on the wheel represents something between 10-20 microns, but I'm not sure. With conical 47 or 48mm burrs you should be OK with the K-Plus steps for espresso, but certainly the JX-Pro's higher resolution will give you the ability to dial in more precisely.

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Team HB

#3: Post by Jeff »

X microns on a flat-burr grinder moves the grinding surfaces X microns closer. With a conical burr, it will be less than X, based on the slope of the burr at the exit portion. This makes it hard to compare two conicals with different burrs. It might be 1.5 or even 3:1 or more with a conical.


#4: Post by Pressino »

Yes, but both grinders the OP was asking about are conical grinders, so in terms of actually grinding, the JX-Pro offers more resolution than the K-plus, which means in regard to making espresso the JX-Pro offers more precise dial-in capability. :)

Team HB

#5: Post by Jeff »

Even if they are both conicals, if they have different burr geometries, the factor can vary significantly.

Here the angle is that of the exit surface of the burr, measured from vertical, or half the included angle of both sides

45° -- 0.71
30° -- 0.50
20° -- 0.34
15° -- 0.26
10° -- 0.17

Without measuring, especially going from marketing photos, my eyes aren't good enough to judge the level of difference in angle.

methylxanthine (original poster)

#6: Post by methylxanthine (original poster) »

So there's really no difference in considerations between choosing a grinder for a full-blown espresso machine vs a lever is that correct? Just purely from my own naïve expectations I think pulling by hand might be less precise (no matter how expert) in exactly a manner that would nullify any resolution differences below a certain grind resolution?

As an analogy take measuring time using a stop watch in hundreds of seconds vs another that can only measure in tenths of seconds. Because the human reaction time is of the 10^-1 order of magnitude, any extra precision afforded by the hundreds stop watch is negligible (and indeed misleading from the point of view of good laboratory practice). While the hundreds stop watch (here the 12.5micron) does make a difference in the espresso machine because the precision of the machine is able to take advantage of it (I hear around 3s per click on 12.5microns) this precision is already "swallowed up" by the imprecisions in pulling a hand lever? So is the tenths stop watch (here the 22microns) already beyond the errors of human lever pulling or not? This is my concern. Please educate me. (Even if you don't have the data to back it up I'd like to hear your gut feeling on this.)

Team HB

#7: Post by Jeff »

I think what coffees you're pulling make a big difference.

A classic espresso blend has a lot of latitude in grind, dose, extraction profile, and temperature. The best of the classic blends work in 1950s home levers, commercial levers, overheated E61s, and modern-day commercial, pump-driven machines. Even an inexpert barista can get an acceptable shot if the grind is "off" and the dose is by wiping across the top of the basket with the excess going back into the doser.

When you start moving into lighter roasts, that sweet spot gets narrower and narrower, to the point where tiny changes in grind make significant differences in the cup.

Dealing with something without sufficient adjustability like a Porlex, or even the highly respected C40 without the RedClix adjuster, can be a frustrating experience. How fine is enough? "Half of whatever you bought last." (Ok, within reason, the current crop of hand grinders that people are using for espresso are probably finer than the point of frustration for most users.)

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#8: Post by Pressino »

methylxanthine wrote:I've narrowed my choice of grinders down to either the k-plus or the jx-pro. on a manual lever like the flair pro 2 (or maybe the la pavoni which i'm condering down the line), will the uncertainties in my hand pressure outweigh any differences that could be gotten down at 12.5 microns,
Oops, I overlooked that you specified you'd be using a lever machine... As methylxanthine pointed out with that apt stopwatch analogy the extra resolution of the JX-Pro is not likely to make a practical difference, not because "pulling by hand might be less precise" but rather because pulling by hand actually allows the barista to be more precise by adjusting the flow during extraction to compensate for differences in grind.

With that consideration I feel more confident in saying that either grinder will do a good job. Choose whichever one you prefer. :)

methylxanthine (original poster)

#9: Post by methylxanthine (original poster) » replying to Pressino »

interesting! i'd never thought it could be due to more precision as you said but that certainly makes sense. in the meantime i learned that there's actually a new k-model coming in stock in the next few days, the k-max (also same burr set 22 microns), so that'll be my most likely purchase at this point.


#10: Post by Urupackers »

1Zpresso have now the J Max model that have coated 48mm burrs and the same ring adjustment as the K models and it have 8.4 microns adjustment, you can look this model too, I have the Jx Pro and the 12.5 microns adjustment is fantastic for espresso, you can work precisely to adjust the time and flow of your shots.