SPOILER WARNING - SPOILER WARNING - SPOILER WARNING

If you wish to play "spot the distribution technique," click here before reading further!

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For the uninitiated, the Weiss Distribution Technique is a popular method for addressing the problem of uneven distribution of coffee grounds in the filter basket, which leads to extraction flaws and the attendant unbalanced and undesirable flavors in the cup.

The WDT is especially effective at dealing with clumping, although as you can read in the thread Why don't pros use the WDT?, not everyone agrees it's necessary. So as part of my research on the Macap M4 Electronic Doserless, I prepared espressos using the WDT and the Stockfleths Move (a rotational re-distribution technique).

(This is your last chance to take the "spot the distribution technique" poll above).

In keeping with the exploratory nature of the Bench, I took videos of all the extractions of the session, including the ones preceding grind adjustments. The extraction below was the first of the session using the WDT:

WDT first shot (too fast)


Whoa Nelly, slow down girl! Tightened the grind adjustment 1-1/2 full turns:

WDT after grind adjustment


Still poured a tiny bit fast, but acceptable. For those keeping track of seconds, I add 3-4 seconds to "normalize" a bottomless pour. So for example, a 24 second bottomless portafilter extraction is approximately equivalent to a 27 second spouted portafilter extraction.

For the next two extractions, I used the same amount of coffee, but redistributed using the Stockfleths Move.

Stockfleths Move first shot


Argh, typing this up now, I see that I accidentally included the post-adjustment WDT video and the pre-adjustment Stockfleths Move video in the poll. Seeing the poll results, 70% are correctly spotting the WDT video. I think the results would have been closer if voters saw this post-adjustment video. Oh well, too late to correct the poll. Next time I'll pay closer attention to which video I link!

To complete the series, I tightened the grind 1/2 turn. A very small adjustment yielded a nicer looking extraction:

Stockfleths Move after grind adjustment


For the record, I believe the WDT is a miracle worker for grinders that produce lots of clumps. But I did learn from this session that a well practiced Stockfleths Move is less labor intensive and the results are very close, in appearance and most importantly, in taste.

UPDATE:

Seeing the comparison of the grounds from the Macap M4 Electronic Doserless and Mazzer Mini Electronic, Chris Nachtrieb, owner of Chris' Coffee Service, contacted Antonio Schiavon of MACAP for his assessment. Antonio explained that the model I have is a prototype and isn't representative of the final production version. He sent a photo of the grounds from the Macap doserless production version and they appear essentially identical to the Mazzer's. Antonio also explained that the final version will have better access for cleaning the last bit of grounds from the chute.

To avoid confusing readers by continuing research of a prototype that differs significantly from the production model, this review is on hold. A replacement production version grinder is expected in 4-6 weeks. Thanks for your patience, and special thanks to Chris and Antonio for listening and acting upon the concerns of HB's espresso enthusiast community.

FireguySpro wrote:So what is to become of this Macap M4 Electronic Doserless prototype? Is there a lucky owner?

HB you had stated earlier that there would not be a retrofit available...is there any way to get Chris to possibly influence Macap to consider such an option?

The prototype goes back to Chris. He didn't mention its final disposition, but I assume he'll sell it. As for a retro kit, I recommend contacting him to express your interest; also think about how much you would be willing to pay for such a kit.

FireguySpro wrote:Is there ANY solution for the static that the M4 produces? There seems to be quite a bit of wasted grinds left within the burrs and snout, so any way to get them into the place where they belong and reduce the waste would be much appreciated.

According to comments from Antonio at the MACAP booth, they eliminated static in the new doserless by placing a grounded wire at the snout exit. I didn't disassemble the prototype, but I can feel a small "spring" up there that I assume is the grounding he alluded to. I'll take a more careful look at how the new doserless M4 reduces static when the production version arrives.

The production version of the Macap M4 Doserless Electronic arrived and I've had a couple weeks to test it. There are some minor tweaks to the exit chute mechanism, but the reduced clumping is small enough that the original photo from earlier in this thread accurately represents the production model:


Clumps are problematic for many grinders, especially doserless ones

One of the advantages of doserless grinders is the repeatable measurements using the built-in timer. To see how the two grinders compared, I ground 7 samples and weighed them. Both grinders rely on a "back pressure" mechanism so the grinds extrude in a steady stream instead of a mixture of clumps and granules. The Mazzer has a screen at the chute exit. The Macap has an approximately 1" long thin metal ribbon bisecting the chute exit; the end at the exit of the chute has a cut V, presumably to help break up clumps before the grounds tumble down the snout. In testing oily or finely ground coffees for ristrettos, I found the Macap's exit occasionally clogged and slowed the motor, requiring gentle prodding up the snout with an implement to break up the clog or even removal of the upper burr carrier to clear the grinding chamber.

The means that you will have to discard a few grams of coffee at the beginning of a session, otherwise the first dose would be a mixture of fresh and stale grounds from the previous session. Below are the measurements in grams:

Macap M4 Electronic Doserless: 7.5, 8.4, 7.9, 8.1, 8.2, 8.2
Mazzer Mini Electronic: 8.2, 8.6, 7.9, 8.3, 8.0, 8.5

Although these aren't statistically significant sample sizes, the standard deviations are 0.314 and 0.274 respectively, suggesting the Mazzer has slightly better reproducibility, though both are more precise than an above average barista dosing manually.

As shown in the poll Doserless to doser and back again... the debate continues, opinion is evenly divided on the merits of doser versus doserless grinders. Indeed, a doser is never used as designed by a home barista (i.e., measuring out a predetermined amount of coffee) because the home barista prepares one or two espressos at a time, not the continuous flow of espressos prepared by professional baristas in a cafe environment.

Choosing between these two grinders isn't easy: The Mazzer Mini Electronic produces grounds that are nearly as clump free as from a doser grinder operated by an experienced barista and evenly distributes grounds without clogging. The Macap M4 Electronic Doserless produces more clumps and may clog with oily coffees or very find grind settings, but has an attractive and easily adjustable timer mechanism (**). In terms of containing the mess, it's a wash: They both do a great job of directing grounds directly into the portafilter, though the Mazzer does have the advantage of a nice portafilter cradle for those too impatient to wait the seven seconds to grind enough coffee for a double. Those who prize neatness and are devotees of the Weiss Distribution Technique are unconcerned about clumping, giving an advantage to the Macap and its nifty adjustment. On the other hand, the fit and finish of the Mazzer line of grinders are the best in the business.

Alas it would be a much easier decision if the Mazzer had the same snazzy LED adjustment mechanism as the Macap at the same price instead of the tiny screwdriver adjustment potentiometer, wouldn't it? But that's what choice is about. Fortunately you can take comfort in the fact that at this level of grinder, there are no "bad" choices, just trade offs.

(**) To change the Macap's single espresso timer setting, press and hold the silver button for a few seconds to enter programming mode. Press the button once to switch to single dose setting. Turn the same silver button like a dial to increase/decrease the time in 0.1 second increments. Press to lock in the setting. Turn the dial counter clockwise to display "Exit" and click to finish. It sounds like a lot of steps, but it's actually intuitive and quick.

I adjusted both grinders using the same coffee to approximately the same pour volume / time. You're right that the grind setting was quite fine since I was dosing to 14 grams.