Dosing: volume vs. weight

[raf]

I am a newbie to espresso perfection (although not to espresso pulling) and have been reading everything I can so that I can improve my technique. I recently bought a new grinder (Mazzer MiniE doserless) and am trying to learn how to get consistent results.

Of course, the key is consistency so therefore I want to keep as many things constant as possible. My approach is to keep my dosing consistent and change only the grind to dial in a good shot. I've read that for a double one should use 12-20g of coffee. From what I've seen, it seems that some people ignore this and simply grind enough coffee to fill up the double basket and then clean off the excess, distribute (via one method or another) and then tamp. But perhaps they have already have calibrated things for their blend and portafilter so that they know they are in the proper weight range.

When I try to dose by volume, I end up with considerably over 20g of coffee. This morning I tried to dose this way. I made the grind a bit coarser and stopped dosing when the double basket was not quite full. I weighed the coffee - it was 29g. I distributed the grinds via a modification of the WDT method. The coffee had lots of crema, but was markedly sour, a sign of under-extraction, I guess.

So, my question is: Should I standardize on weight or on volume?
If I use volume, the weight will be way over the recommended.
If I use weight, the basket will be only 1/2 full, tamped puck down 3/8" from the top lip of the basket.

Any and all comments and advice humbly solicited.

Thanks,
Martin

[mrgnomer]

After about a year of being obsessed with espresso I'm still relatively new but maybe I can help.

I grind for dose and dose for volume. Two rounded espresso scoops (the one that comes with mostly all the machines) grinds to about the volume for a double. I distribute with a modified Stockfleth's move and with the bottom of my extended pointer finger scrape off and level NSEW. My fingers are a bit meaty so the bottom of my extended pointer finger is slightly convex leaving a slightly concave surface to the distributed grounds. I've measured it out a few times and it's around 17-18g of coffee. With a light, 30 lb NSEW wiggle tamp and a tamper weight finish polish the puck rim ends up just under the basket ridge after tamping.

I roast my own so the roast is rarely older than 7 days and I also like a light to med roast. My machine is an e61 HX so after taking the pre infusion and the generous blooming of the grinds into account the puck expands very well and the extraction is consistenly even and all crema.

I'd say try to standardize by volume but weigh your dose for a while to get an intuitive feel for an ideal range for extraction. Even distribution and tamping also make a big difference as well as the freshness of your roast. Find a method that consistenly gives you even results with respect to distribution and tamping and you'll be better able to isolate other variables like dose volumes and grind fineness. Assuring even puck density and grind fineness for the kind of extraction you want is most important, IMHO.

[jesawdy]

When I try to dose by volume, I end up with considerably over 20g of coffee. This morning I tried to dose this way. I made the grind a bit coarser and stopped dosing when the double basket was not quite full. I weighed the coffee - it was 29g.

What machine and basket do you use?

I am using the EPNW LM ridgeless, and about the most I have packed into it and still be able to lock the PF into a Rancilio Silvia is 22g or so. And that was with some difficulty. Are you sure your scale is accurate? Perhaps you are grinding very fine and the Mazzer does not fluff too much?

I started out by weighing out 16-18 grams, and grinding until empty, discarding the first little bit out of the grinder. I have moved away from that after I felt familiar enough with the process to volume dose. You might try that same approach, and adjust grind until extracion time seems right and see how full the basket is once that is dialed in. When I weighed the beans out, I did not always have a full basket, and would sweep the grinds NSEW and do a Stockfleth's in such a way that the the grounds leveled pretty well even though below the basket rim. Now that I volume dose, I may be getting a bit closer to 18-19g in the basket, I need to check after a level and tamp to see whare I am at.

-Jeff

[raf]

What machine and basket do you use?

I'm using a Faema "Professional". It is a non-E61 single boiler with a separate steam line that is somehow heated up on demand. I don't fully understand it, but I do know that I can steam and pull shots simultaneously. I'm using a double shot basket - straight sides. Looks to me like all the other double baskets I've seen. Looks the same as a friend's Silvia double.

I am using the EPNW LM ridgeless, and about the most I have packed into it and still be able to lock the PF into a Rancilio Silvia is 22g or so. And that was with some difficulty. Are you sure your scale is accurate? Perhaps you are grinding very fine and the Mazzer does not fluff too much?

I'll bet that the scale is very inaccurate, good point. I'll try to fix that. Also, could be that this blend tends to grind very fine. I just received the Mazzer so I'll try experimenting with more coarse grinds and see how full I get the basket. I am suspicious of this since i seem to remember when I was setting up the grinder last weekend I was using some old beans and they seemed to fill the basket much more than the blend I was using today.

I started out by weighing out 16-18 grams, and grinding until empty, discarding the first little bit out of the grinder.

I am weighing the ground coffee not the beans. I am doing this since the Mazzer will tend to trap a certain amount of grinds behind the static screen at the end of the exit tunnel of the burrs. I felt it would be more acccurate to weigh the coffee that actually makes it into the basket.

I have moved away from that after I felt familiar enough with the process to volume dose. You might try that same approach, and adjust grind until extracion time seems right and see how full the basket is once that is dialed in. When I weighed the beans out, I did not always have a full basket, and would sweep the grinds NSEW and do a Stockfleth's in such a way that the the grounds leveled pretty well even though below the basket rim. Now that I volume dose, I may be getting a bit closer to 18-19g in the basket, I need to check after a level and tamp to see whare I am at.
-Jeff

This is where I hope to be once I understand what "normal" is and can be more consistent. I sure don't want to measure every shot I pull!

Thanks for your help.

Martin

[jesawdy]

For kicks, you might try to weigh the whole beans, maybe add a gram and grind until empty. I discard the first liitle bit as that may be some older coffee being pushed out the chute, and you may have some trapped in the grinder at the end. You might try dosing into basket and weighing the full basket, subtracting the basket weight and see what if any is left behind in the grinder. I think this approach will also help you towards learning volume dosing straight from the grinder, as the coffee is not being transferred one or more times nor compacted in any way before hitting the basket.

There are folks here and on CG that will claim that coffee noticably stales within minutes of grinding, so I am of the mindset of having the coffee ground for the bare minumum of time before the espresso is extracted.

[RapidCoffee]

When I try to dose by volume, I end up with considerably over 20g of coffee. This morning I tried to dose this way. I made the grind a bit coarser and stopped dosing when the double basket was not quite full. I weighed the coffee - it was 29g. I distributed the grinds via a modification of the WDT method. The coffee had lots of crema, but was markedly sour, a sign of under-extraction, I guess.

So, my question is: Should I standardize on weight or on volume?
If I use volume, the weight will be way over the recommended.
If I use weight, the basket will be only 1/2 full, tamped puck down 3/8" from the top lip of the basket.

Hi Martin. A sour extraction could easily be due to a low brew temperature. I don't know anything about the Faema Professional, although your description ("single boiler with a separate steam line that is somehow heated up on demand") sounds suspiciously like an HX machine. If so, make sure you read the HX Love article.

29g sounds far too heavy for a double basket. If your scale is that inaccurate - possibly off by 50% - either get another scale or quit worrying about the weight. 3/8" of headroom above the tamped puck is an awful lot. I'd suggest aiming for 1/8" or so, near the basket ridge line.

FWIW, I dose strictly by volume and get reasonably consistent pulls.
________
John

[randomperson]

For kicks, you might try to weigh the whole beans, maybe add a gram and grind until empty. I discard the first liitle bit as that may be some older coffee being pushed out the chute, and you may have some trapped in the grinder at the end. You might try dosing into basket and weighing the full basket, subtracting the basket weight and see what if any is left behind in the grinder. I think this approach will also help you towards learning volume dosing straight from the grinder, as the coffee is not being transferred one or more times nor compacted in any way before hitting the basket.

There are folks here and on CG that will claim that coffee noticably stales within minutes of grinding, so I am of the mindset of having the coffee ground for the bare minumum of time before the espresso is extracted.

This is essentially what I do also -- weigh my whole beans before the shot until I'm at 17.5 grams; grind until empty (with a whole lot of shaking and using the Click Clack lid on the Rocky to expel as much leftover coffee as possible); NSEW sweep; tamp. This leaves me with about 17 grams and a puck that is just below the spring mark in the basket. Arguably I could updose more, but I am not fond of the bitter intensity that seems to be emphasized in the cup when I updose beyond 18 grams.

I go through all this weighing business because I am after consistency too -- just to have one less variable to worry about.
I have had good results dosing by volume but I found that volume changes significantly depending on the fineness of the grind so you can end up updosing even more -- not a good recipe for my palate.

So, with weight varying depending on the beans used; and volume varying depending on the grind setting, who knows what's best? I ended up just going with weighing per shot, before the shot (to keep it simpler), after determining the average amount that Rocky eats no matter what I do!

I imagine this is even more complicated with the Mini E, since it uses a timer for its dosing and there again grind fineness will affect the amount ground. So, I'll be interested to hear other thoughts about this issue, as I am keenly interested in the Mini E myself! But, my thought was that if I did end up buying the Mini E that I would still measure per shot, and grind until empty. Talk about a waste of electronics!

BTW I also determined that the scale used is critical -- I've migrated to a pocket scale (it's called "My Weigh") for jewelers --and drug dealers, I imagine! -- but it is very accurate to the .1 gram and comes with a 100 gram weight for calibration purposes. It was less than $25 and well worth it.

[HB]

I imagine this is even more complicated with the Mini E, since it uses a timer for its dosing and there again grind fineness will affect the amount ground. So, I'll be interested to hear other thoughts about this issue, as I am keenly interested in the Mini E myself! But, my thought was that if I did end up buying the Mini E that I would still measure per shot, and grind until empty. Talk about a waste of electronics!

As mentioned in Exercises for tuning your barista techniques, I go back and forth between volume and weight dosing, especially when testing new equipment. I don't care all that much about the particular weight (i.e., 16.5 versus 17.5 grams), just that it's consistent. Volume dosing by level-cutting a basket that hasn't been settled (no "tap tap") will be extremely consistent; for the double baskets I use, the grinds without settling are around 14-15 grams (some coffees are more dense, e.g., Intelligentsia's Yemen Sanani and decafs). When I evaluated the Mini E, I set the timer to half the normal dose for most coffees and ran it twice. Depending on the coffee, I would discard a little or push the momentary switch for a couple seconds to "top off" the basket. This wouldn't be necessary if you changed blends infrequently.

[espressoperson]

I dose by volume but use weight as a guide to achieve the ideal volume.

I started to do this by the necessity of using a deeper and narrower 49 mm basket. On the one hand, the typical heap above, tap, fill gaps nsew, then level the top never got enough grinds into the basket to give me consistent volume. On the other hand, I could not create a consistent heap above the basket by eye to stockfleth a consistent volume into the basket.

So I weigh out the beans per shot and grind and brush all into basket and in a heap above. Tap 3 times to even out the grinds and stockfleth all into basket. Then tamp. Here's the first place to look for feedback. Coffee too high in the basket - decrease the weight next time. Too low in the basket - increase the weight next time. The next place to look for feedback is in the cup. What is the contribution of the dose (independent of grind, distribution, tamping, etc.) to the shot and does it need to be adjusted?

IMO this adjustment of weight to achieve ideal dose is no different than other adjustments we make shot to shot. If we don't hit the right grind on the first shot we change the grind for subsequent shots. If we have temperature control and the shot is too sour or bitter we change the temperature to compensate on the next shot. So likewise, tweaking the weight from shot to shot to reach the ideal volume is a similar adjustment.

This method has the following advantages:

1. You learn the right weight for the right volume and how it varies. The biggest change factors I experience are type of coffee and age of coffee. For example my typical dose of Monkey blend is 16.4 g and Decaf Donkey blend is 16.8 g. And the weights creep up over time to keep the volume constant. So if I have any coffee that lasts more than a week I'll be dosing 16.6 and 17.2 respectively for these coffees. Other variables are roast level, humidity, and "extreme" coffees like monsooned malabar or blends that rely on them (Dolce).

2. Coffee is always freshly ground just before using.

3. You can switch coffees for every shot without having multiple grinders or extra grinder cleaning.

4. Very little coffee is wasted. This seems to bother me more than the many profligates who hang out here .

Disadvantages:

1. Extra step of weighing. I also use a 0.1 g scale, weigh in a little stainless steel cup, then toss into grinder. Really not much more difficult than using a standard scoop to fill the grinder.

2. Extra step of sweeping out grinder per shot. Do you know how looong an empty mazzer mini keeps spinning after it is shut off before you can brush out the chute?

[Psyd]

2. Extra step of sweeping out grinder per shot. Do you know how looong an empty mazzer mini keeps spinning after it is shut off before you can brush out the chute?

Doesn't that happen whether you dose by weight, volume, counting beans, whatever? Oh, nevermind, the thing is slowed by the beans that remain in the hopper, and under the grinding surface. Yeah, I'm with EP, one shot at a time, or "One Shot One Kill"...

; >

[raf]

For kicks, you might try to weigh the whole beans, maybe add a gram and grind until empty. I discard the first liitle bit as that may be some older coffee being pushed out the chute, and you may have some trapped in the grinder at the end. You might try dosing into basket and weighing the full basket, subtracting the basket weight and see what if any is left behind in the grinder. I think this approach will also help you towards learning volume dosing straight from the grinder, as the coffee is not being transferred one or more times nor compacted in any way before hitting the basket.

There are folks here and on CG that will claim that coffee noticably stales within minutes of grinding, so I am of the mindset of having the coffee ground for the bare minumum of time before the espresso is extracted.

This, I think, is where I am headed. I do grind right into the basket and for now weigh the ground coffee and then quickly take out the empty portafilter, insert the basket and pull the shot. As soon as I get straightened out a bit, I think I'll try weighing the beans and then figuring out how that relates to ground weight and volume. Thanks for the suggestion.

[raf]

Hi Martin. A sour extraction could easily be due to a low brew temperature. I don't know anything about the Faema Professional, although your description ("single boiler with a separate steam line that is somehow heated up on demand") sounds suspiciously like an HX machine. If so, make sure you read the HX Love article.

29g sounds far too heavy for a double basket. If your scale is that inaccurate - possibly off by 50% - either get another scale or quit worrying about the weight. 3/8" of headroom above the tamped puck is an awful lot. I'd suggest aiming for 1/8" or so, near the basket ridge line.

FWIW, I dose strictly by volume and get reasonably consistent pulls.
________
John

Hi John,

BINGO! (and duh!) My scale is woefully inaccurate. Yesterday I purchased a low-end scale from a local "The Source by Circuit City" (formerly Radio Shack here in Canada) and learned that my scale was off at least 25% and this probably changed for each weighing! Please see post below for a full report on today's experience with dosing.

Also, I think you may be right about the low temperature. I am going to switch blends today and see what happens since I have no ability to change the temperature. I have read the various HX articles and numerous posts so I understand the issues. I need to open up the machine to see exactly what is going on, but I think the bottom line is that I will not have any per blend temperature control. I will be upgrading (this hobby is quickly becoming an obsession!) to a machine that will have temp control.

[raf]

This is essentially what I do also -- weigh my whole beans before the shot until I'm at 17.5 grams; grind until empty (with a whole lot of shaking and using the Click Clack lid on the Rocky to expel as much leftover coffee as possible); NSEW sweep; tamp. This leaves me with about 17 grams and a puck that is just below the spring mark in the basket. Arguably I could updose more, but I am not fond of the bitter intensity that seems to be emphasized in the cup when I updose beyond 18 grams.

I go through all this weighing business because I am after consistency too -- just to have one less variable to worry about.
I have had good results dosing by volume but I found that volume changes significantly depending on the fineness of the grind so you can end up updosing even more -- not a good recipe for my palate.

So, with weight varying depending on the beans used; and volume varying depending on the grind setting, who knows what's best? I ended up just going with weighing per shot, before the shot (to keep it simpler), after determining the average amount that Rocky eats no matter what I do!

I imagine this is even more complicated with the Mini E, since it uses a timer for its dosing and there again grind fineness will affect the amount ground. So, I'll be interested to hear other thoughts about this issue, as I am keenly interested in the Mini E myself! But, my thought was that if I did end up buying the Mini E that I would still measure per shot, and grind until empty. Talk about a waste of electronics!

I'm not sure it is more complicated with the MiniE since I have removed the finger guard at the top of the cylindrical chute (NOT the screen at the end of the exit tunnel leading from the burrs!!!!) So I can easily brush out almost all of the leftover grinds before changing fineness. I plan to use the timed grinding feature once I have some of these variables sorted out. I'll report if I think its useful and if the timers can eliminate the need for weighing the beans/grounds (I doubt it).

Your comments on updosing vs bitterness are interesting to me. I think this is where I'll be looking once I understand how to get consistent pours.

BTW I also determined that the scale used is critical -- I've migrated to a pocket scale (it's called "My Weigh") for jewelers --and drug dealers, I imagine! -- but it is very accurate to the .1 gram and comes with a 100 gram weight for calibration purposes. It was less than $25 and well worth it.

See previous response. I feel a little sheepish that I did not look at this first!

[raf]

As mentioned in Exercises for tuning your barista techniques, I go back and forth between volume and weight dosing, especially when testing new equipment. I don't care all that much about the particular weight (i.e., 16.5 versus 17.5 grams), just that it's consistent. Volume dosing by level-cutting a basket that hasn't been settled (no "tap tap") will be extremely consistent; for the double baskets I use, the grinds without settling are around 14-15 grams (some coffees are more dense, e.g., Intelligentsia's Yemen Sanani and decafs). When I evaluated the Mini E, I set the timer to half the normal dose for most coffees and ran it twice. Depending on the coffee, I would discard a little or push the momentary switch for a couple seconds to "top off" the basket. This wouldn't be necessary if you changed blends infrequently.

This is my thinking now also. I think I finally have sorted out the volume dosing and am now getting very consistent (in terms of weight) results. I'll be giving more details below.

[raf]

I dose by volume but use weight as a guide to achieve the ideal volume.

I started to do this by the necessity of using a deeper and narrower 49 mm basket. On the one hand, the typical heap above, tap, fill gaps nsew, then level the top never got enough grinds into the basket to give me consistent volume. On the other hand, I could not create a consistent heap above the basket by eye to stockfleth a consistent volume into the basket.

So I weigh out the beans per shot and grind and brush all into basket and in a heap above. Tap 3 times to even out the grinds and stockfleth all into basket. Then tamp. Here's the first place to look for feedback. Coffee too high in the basket - decrease the weight next time. Too low in the basket - increase the weight next time. The next place to look for feedback is in the cup. What is the contribution of the dose (independent of grind, distribution, tamping, etc.) to the shot and does it need to be adjusted?

How does one determine the "the contribution of the dose (independent of grind, distribution, tamping, etc.) to the shot"? I have read some hints, but I'd love to hear thoughts on this subject. I would have thought that (within reason) more coffee == finer grind and vice-versa in terms of other variables like pour time. But understanding the effect on taste of these variables would be very helpful indeed.

IMO this adjustment of weight to achieve ideal dose is no different than other adjustments we make shot to shot. If we don't hit the right grind on the first shot we change the grind for subsequent shots. If we have temperature control and the shot is too sour or bitter we change the temperature to compensate on the next shot. So likewise, tweaking the weight from shot to shot to reach the ideal volume is a similar adjustment.

This method has the following advantages:

1. You learn the right weight for the right volume and how it varies. The biggest change factors I experience are type of coffee and age of coffee. For example my typical dose of Monkey blend is 16.4 g and Decaf Donkey blend is 16.8 g. And the weights creep up over time to keep the volume constant. So if I have any coffee that lasts more than a week I'll be dosing 16.6 and 17.2 respectively for these coffees. Other variables are roast level, humidity, and "extreme" coffees like monsooned malabar or blends that rely on them (Dolce).

2. Coffee is always freshly ground just before using.

3. You can switch coffees for every shot without having multiple grinders or extra grinder cleaning.

4. Very little coffee is wasted. This seems to bother me more than the many profligates who hang out here .

Disadvantages:

1. Extra step of weighing. I also use a 0.1 g scale, weigh in a little stainless steel cup, then toss into grinder. Really not much more difficult than using a standard scoop to fill the grinder.

2. Extra step of sweeping out grinder per shot. Do you know how looong an empty mazzer mini keeps spinning after it is shut off before you can brush out the chute?

This is an interesting approach. I don't think the extra steps are very onerous.

I don't seem to have any problem sweeping out the MiniE; it seems to stop quite quickly. (Except of course the one time I jumped the gun and ended up grinding a few of the bristle tips on my brush!) I also use the whoosh of air produced when the burrs are empty to move some of the grounds that are further up the exit tunnel down towards the static screen where I can coax them out with a brush.

[raf]

Well, what a trip! I sure have learned a lot in the past few days, aided immeasurably by the great folks in this forum. (My wife says that at least I'm providing entertainment to the members of this site! Not sure what she means by this...)

In any case, I think I finally understand what is going on and am making progress with consistency. Getting a reasonably accurate scale made all the difference. I now can dose and distribute by volume and achieve remarkably accurate (+-0.1g) weights in the basket.

19.3g ground weight == a full 58mm basket with Cherry Bomb blend from Dark City Roasting in Toronto
16.1g ground weight == a full 58mm basket with indigo Blue (same supplier)

I have been repeating this dosing over a dozen shots and if I was so inclined, could probably eliminate the weighing altogether and be confident of my consistency. Since it is really very little trouble to weigh each basket I will continue for the time being.

I also am now getting very good looking pucks so I think my tamping is good and is consistent. By good looking pucks I mean that they are intact, show no obvious signs of gross channeling, reasonably dry and when I break them apart in various spots they seem to have the same amount of moisture throughout the depth. The next step would be to get a naked portafilter, but since I'll be changing machines within a month or so, I think I'll wait for the new machine to buy it.

My pours are excellent in terms of crema: almost all crema as it extracts, settling out to 3/8" to 1/2" thick. So I think I finally am getting close. But 2 issues still remain: extraction time and taste. (The beans I am using are within 4 days of roasting.)

Taste:

The Cherry Bomb blend is consistently lemony. My guess is now that this is due too low of a group temperature.
The Indigo Blue blend is much better, but I think could be better if I could eliminate a slight bitterness. Since i just started experimenting with this blend I have not reached a conclusion.

Extraction time: note that currently I'm holding the espresso volume constant at 2.0 oz.

The Cherry Bomb blend at 19.1g consistently extracts too fast: 18-20s, even with finer grinding. this morning I stopped adjusting finer and moved to the Indigo Blue.
The Indigo Blue blend at 16.1g extracts even faster: 10-12s! I have only pulled 5 shots with this blend, each time grinding finer. (I needed to stop before my head exploded and my craving for a morning coffee would have eliminated my attempts at scientific objectivity!) Even with a 12s extraction, the espresso was very worthy of drinking, especially in a morning cap.

So, where to go next? I think I need to get the extraction times under control. My inclination is to leave the dosing alone since I finally have consistency and keep moving the grind finer and finer until I get better extraction times. Comments please, and once again thanks for everyone's help.

Martin

[randomperson]

Definitely standardize the dosing and tamping and just grind finer until your shot times get in the proper range. That should do it!

If your machine is an HX you could muck with your flush routine to get very good temp control -- but save that for later!

I will be very interested to hear more about your E after you fine-tune everything!

[mrgnomer]

So, where to go next? I think I need to get the extraction times under control. My inclination is to leave the dosing alone since I finally have consistency and keep moving the grind finer and finer until I get better extraction times. Comments please, and once again thanks for everyone's help.
Martin

Dialing in the grind is important. When I upgraded to a Macap M4 stepless I followed the grind adjustment directions and got a grind so coarse my naked pf pours were gushing and squirting all over the place. I thought it was me and my technique so after burning at least a pound of beans trying everything to get a good dose and even distribution/tamp I finally went finer to slow down the pours until I found the sweet spot. After finding the good grind fineness for my roast/blend the gushing and squirting were gone and with a good dosing, distributing and tamping the shots are consistently very good.

What continues to be reiterated I find is very true: the main responsibility for making very good espresso is at the handle end of the pf. Getting a good dose really helps to bring the best out of a blend, I find, but having a good and consistent method of distributing and developing a good method and touch for even tamping is most important. IMO once you get the barista skills down you'll be able to change other variables and get predictable results in the cup. Other variables can also change on you like environmental humidity or roast/blend and you'll be able to control them as well by making adjustments once your barista skills are good and consistent.

[Merlino]

I measure beans directly into the mouth of my mazzer mini and I know roughly how high 18 grams are stacked. I then grind, clean out the chute and dose. I then use a needle to declump after which I NSEW. This method fills my double basket to the brim with very little excess. My basket is the standard double which came with my silvia.

Hope I helped. $0.02