Measuring dose by weight vs volume? - Page 2

by HB on Tue Mar 02, 2010 2:16 pm

In my experience with La Marzocco, dosing until the coffee makes contact with the dispersion screen yields a more even extraction. Some baristas, notably 2003 WBC winner Paul Bassett, crammed the basket full. That said, I cannot think of another espresso machine that typically performs better updosed.

by **another_jim** on Tue Mar 02, 2010 2:23 pm

malachi wrote:Dosing by volume with practice is feasible, accurate and efficient.
It is not - to be clear - something I would recommend to most home baristas as the "with practice" assumes a lot more practice (and coffee) than is economical (or realistic).
But saying that it cannot be done in a bar scenario is untrue - and saying that "well trained" professional baristas accept variance of 25% in extraction is even more untrue.

I think this is a myth based on self observation in training labs. I've visited the top Chicago bars four times each in the last two months, each time with a group of friends. They were gloriously busy, but the shots we got varied from ristretto to normale, and pull times varied by 10 seconds. This is with two baristas charging around serving mostly monster drinks. The more the bars pushed the envelope on dose and flow, the worse the variance.

Abe, who was with me on the latest tour, done for the day after judging the home roast competition, was even more pessimistic about the shot variance than I was. He thought they were varying by a gram at least.

As is always the case, the best shots were great, and the worst shots were unacceptable. If third wave bars really want to sell espresso, they need to achieve Italian levels of consistency, while exceeding their mediocrity. For portion grinding, I think a timed grinder, calibrated each day, is the way to go on this -- it does get to the same level of accuracy as a conventional doser -- and I'm fairly sure eyeballed volume dosing does not.

by **yakster** on Tue Mar 02, 2010 4:44 pm

I know that this conversation has been addressing consistency of shots with the same bean, and I agree that dosing by weight is a great way to achieve this (this is what I do), but it also brought up the question for me on how you address different beans.

Normally, for me, I dose 7 g singles and 14 g doubles in my La Peppina and I'll start with that measurement when I switch beans (at least weekly if not more). I ran across one blend (Moka Kadir) that must have been light because 14 grams was too much volume in the filter basket, I ended up lowering the dose to suit the dosing volume, but measured the new dose with a gram scale and used the scale thereafter for consistent dosing. This bean seemed outside the norm from most of the espresso I pull in terms of density... on further reflection, I pulled this bean right after tearing down the machine and replacing the gaskets... I suppose it's possible the dispersion block spacing has changed. I'll have to watch this. I just received a new dispersion block because I scratched and bent the old one trying to get a stuck screw out of the group.

So, I guess I'm asking if you consider volume first or weight when dialing in a new blend. I think now that I have a pretty good clue why the difference occurred, I have an answer... starting with weight always worked for me before the tear-down.

by **another_jim** on Tue Mar 02, 2010 4:55 pm

This is not complicated. Dial in a new blend at the middle of your weight range. Once it's flowing correctly, if the coffee tastes like someone is jackhammering your tongue, use less; if it tastes like dishwater, use more.

by **jammin** on Tue Mar 02, 2010 5:04 pm

^ is that a quotable quote I see?;)

by HB on Tue Mar 02, 2010 5:08 pm

Jim's a one-man quotable quote machine. :lol:

by **malachi** on Tue Mar 02, 2010 6:53 pm

another_jim wrote:I think this is a myth based on self observation in training labs. I've visited the top Chicago bars four times each in the last two months, each time with a group of friends. They were gloriously busy, but the shots we got varied from ristretto to normale, and pull times varied by 10 seconds. This is with two baristas charging around serving mostly monster drinks. The more the bars pushed the envelope on dose and flow, the worse the variance.

Abe, who was with me on the latest tour, done for the day after judging the home roast competition, was even more pessimistic about the shot variance than I was. He thought they were varying by a gram at least.

As is always the case, the best shots were great, and the worst shots were unacceptable. If third wave bars really want to sell espresso, they need to achieve Italian levels of consistency, while exceeding their mediocrity. For portion grinding, I think a timed grinder, calibrated each day, is the way to go on this -- it does get to the same level of accuracy as a conventional doser -- and I'm fairly sure eyeballed volume dosing does not.

I managed coffee bars.
It's not based on self observation but on measurement of employees.
On the bar.

Measuring shot time, shot volume and tasting results.
Random drop in - and in many cases using proxies to avoid detection.

QC for the cafes.

I think it's equally likely that your experience is second hand observation of a limited sample set.

I would, to be honest, take real exception to the classification of this as "myth" but figure I should first ask what you mean by the word (as I am notorious for my semantic narrow-mindedness).

myth
Pronunciation: \ˈmith\
Function: noun
Etymology: Greek mythos
Date: 1830
1 a : a usually traditional story of ostensibly historical events that serves to unfold part of the world view of a people or explain a practice, belief, or natural phenomenon b : parable, allegory
2 a : a popular belief or tradition that has grown up around something or someone; especially : one embodying the ideals and institutions of a society or segment of society <seduced by the American myth of individualism — Orde Coombs> b : an unfounded or false notion
3 : a person or thing having only an imaginary or unverifiable existence
4 : the whole body of mythsmyth
Pronunciation: \ˈmith\
Function: noun
Etymology: Greek mythos
Date: 1830
1 a : a usually traditional story of ostensibly historical events that serves to unfold part of the world view of a people or explain a practice, belief, or natural phenomenon b : parable, allegory
2 a : a popular belief or tradition that has grown up around something or someone; especially : one embodying the ideals and institutions of a society or segment of society <seduced by the American myth of individualism — Orde Coombs> b : an unfounded or false notion
3 : a person or thing having only an imaginary or unverifiable existence
4 : the whole body of myths

To me none of these apply in this case.

Beyond all this - it seems like your own observation are that the higher the volume the greater the variance which would actually point to dosing by volume with consistency being easier at home than in a bar. Given this, what again is the argument for dosing by weight? Simply because it can be "measured" easily?

by **malachi** on Tue Mar 02, 2010 6:55 pm

TimEggers wrote:Most interesting, Chris can you elaborate on the case for a coffee needing to hit the dispersion screen?

I didn't say "need" i said "desirable" - it's quite different.
I believe there was a very good article in Barista Magazine years ago about the specific (desired) flavour profile that resulted from an extremely high dose. It was by either George Sabados or Paul Bassett.

by **another_jim** on Tue Mar 02, 2010 7:28 pm

Chris, I mean the first: a group-internal belief whose group-internal standards of verification make it immune to the commonsense notion of real world experience. It is a common problem in corporations, governments, families, etc. The higher the morale and esprit de corps, the more myths abound.

In the dosing case, you didn't check on your baristas during busy hours, nor when they didn't know you are there, etc. etc. So your observed standards have a massive self fulfilling observer effect. I grew up in restaurants and bars, and the quality went through the roof when my grandparents, the owners, were there. When I was watching alone, a fly on the wall, the story is rather different.

Go to your star bar, anonymously, hang out, and discretely watch; or ask a friend. I'm more than willing to be corrected on this. But my guess is that in the heat of battle, with no QC person hovering, the consistency will go to hell. This is the reason why head chefs are either massive SOBs, or even scarier "more in sorrow than anger" types.

This inconsistency under pressure when using an eyeballing technique is not something anyone familiar with industrial engineering would blame on the person doing it -- the point is to come up with an inherently more reliable mechanism. Italian barmen, who spend a lifetime pulling nothing but singles, used dosers. Do you honestly think someone with a few months to years experience, pulling a menu of ten different drinks, can be as consistent using an eyeballing method? This seems like a major league myth. I think even with WBC baristas, during rush hour you will need a grinder that does either exact timing or weighing to stand a chance.

I've become the "Dose-Nazi" in the last few years. But I think I'm right on this; people dose inconsistently, and as a consequence they get inconsistent taste, and they cannot hope to control the flavor by finding the correct dose for each blend. The finger-swipe, eyeball the volume, methods used in third wave cafes are, to my mind, inconsistent and of low quality.

You've worked in restaurants. Would any self respecting place do their portion control like this?

by **ethorson** on Wed Mar 03, 2010 1:53 pm

I agree 100% with Jim:

I've become the "Dose-Nazi" in the last few years. But I think I'm right on this; people dose inconsistently, and as a consequence they get inconsistent taste, and they cannot hope to control the flavor by finding the correct dose for each blend. The finger-swipe, eyeball the volume, methods used in third wave cafes are, to my mind, inconsistent and of low quality.

I have struggled for a long time trying to dose by volume, with very inconsistent results (mostly bad). Even though it takes more time I now weigh each shot into the basket, WDT, and tamp. The results are now very consistent even at the normal 12 gram dose. I can get close to the correct dose by stopping my Mazzer Mini grinder at the point where the pile of coffee just reaches the outlet port, then emptying the doser contents into the basket.

After WDT I snap the basket into the portafilter, give a little shake to level, remove the "yogurt cup", and tap the basket lightly to settle the coffee into the void at the edge. After a single, straight tamp (no twist) I lock and load.

Now that my espresso is tasting better I prefer the standard 12 gram dose and use a lot less milk. My favorite drink has progressed from 12 oz lattes to 6 oz cappuccinos and finally to macchiatos. I am still not quite to the point where I prefer straight espresso, but working on it.


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