LM USA have a very interesting article on their blog about extraction consistency with several different methods of eyeballing or measuring the dose and shot volume and weight.

http://www.lamarzoccousa.com/blog/ben-k ... lumetrics/

The results mirror what was reported in a previous experiment mentioned in Why should I care about blonding? Weighed doses and metered (presumably the same goes for weighed) shots produce shot-to-shot consistency far beyond any method involving eyeballing and subjectively deciding when to end the shot.

It makes alot of sense. I know the Synesso Sabre also volumetrically measures the shot in the cold water stream before it makes it to the brew boilers. Apparently its more accurate and less likely to cause scale problems as well at that point. You can always stop the shot manually, if you have the time and it looks like its going awry.

They also make the point that not only is volumetric dosing significantly more consistent, but the barista doesn't have to waste time standing there and watching every single shot pour.

I was hoping this would generate a bit of discussion. While the idea of carefully weighing doses and shots has become somewhat accepted on HB, many people still believe it's massive overkill that makes very little difference in practice. The results in the article speak for themselves and certainly seem to indicate otherwise.

Very interesting since I rarely use the automatic feature of my machine as I found its results to be visually inconsistent. Using the programmed button, I would go from having a half filled demitasse to one that is overflowing. Obviously, the home barista would need to control some other variables as well (dose in particular). As I rely on the Vario's timed grinding feature and my eye to determine dose (due to convenience and laziness) the variance in my shot volumes may be due to dose/grind inconsistencies rather than a faulty flow meter.

One must also consider the position of the flow meter in the espresso machine. A flow meter placed before the OPV may result in different results in the cup due to water being diverted to the drip tray that may have been measured by the flow meter.

At the Pressure/Flow event LM was making a huge point about volumetric dosing. They also claimed that because their Strada EP uses a gear pump for each group, they no longer need to use a flow meter to control volumetrics. They feel that's good news for them since flow meters have issues and their new flagship machine avoids those.

For the busy cafe, I can easily see how accurate volumetric dosing will improve consistency. We home baristas have the luxury of time so volumetrics become less important. LM/Mazzer seem to be only a couple of steps away from producing a superauto espresso system.

After first dialing in by blonding, I always weigh the espresso/cup while each shot is running and stop at target weight. This probably ends up similar to volumetric dosing. I find the results to be more consistent than I have gotten any other way (I weigh the dose also). Tekomino's "digital espresso" post got me to try it a while back.

I tend to wonder if reported experiences of inconsistency with volumetric dosing are because of poor flowmeters, or insufficiently consistent coffee doses, or both.

The other problem with volumetric on traditional machines is the primitive user interface, which requires you to first set it to program mode, and then run a shot to store it. You can't edit or adjust the volume except by starting all over.

I think for the purposes of the discussion, weighing the shot is functionally identical to using a high-end flow meter; it's just not as practical in a cafe setting. The point is that weighing the dose and carefully measuring the shot in some way (well-designed flow meter or scale) both rather significantly improve extraction consistency in a way that can objectively tested. This sort of routine is often looked down on as needlessly fussy, something only newbies need to do, or a crutch, but it genuinely does produce significantly more consistent espresso.

I'd be interested to know how many HB members routinely weigh doses and shots nowadays. It seems to have gained a lot of acceptance in the last year or two, and it certainly made an enormous difference to my own espresso making.

Bob_McBob wrote:I'd be interested to know how many HB members routinely weigh doses and shots nowadays. It seems to have gained a lot of acceptance in the last year or two, and it certainly made an enormous difference to my own espresso making.

I do but maybe you want to start a new thread with a poll?

I weigh the dose, every single shot, without fail.

However I don't often weigh the shot as its pulling. I have nothing against it, and I would do it every shot, but the two scales I have just aren't great fits on the Duetto drip tray. I have been meaning to buy a new scale specifically for this purpose, but I haven't yet.


Aside from using a high end Mazzer-E grinder, with a full hopper, the only way I know how to make espresso that is consistent, shot to shot to shot, is by weighing and single dosing. I can't use a doser and dose by volume and be consistent, nor do I wish too, because of the amount of waste that technique inherently has. However, I dont see this as any problem at all, because I haven't tossed a shot due to gross defects in dose or distribution in years. Aside from a few not so perfect shots to dial in, excuse my percieved arrogance, but every shot I pull is dead centered perfect pour, and the proper ratio(again, once dialed in)

But, a hopper-loaded Mazzer Robur E, Kony-E, Major-E(Ive used the MAjor/Robur E's, I just assume the Kony would be the same), those grinders can accurately dose right into the portafilter shot after shot, and the times Ive used them, IVe been able to forego the scales completely and still be consistent. But not in a home use scenario.

I always weigh doses but rarely the shot unless I'm trying to diagnose a problem. I think my little La Pavoni has very consistent water dosage even though it's not very adjustable. Pulling cup out early or multiple lever pulls are the only way to adjust volume. Besides putting the scale right under the cup on the drip tray is really awkward, I don't want drips on the scale. It responds too slowly anyway too...