malachi wrote:One of the areas of training (taught to me originally by Aaron de Lazzer) was around consistent dosing. The test was to dose 10 times and have all 10 be no more than 0.3 gram difference. There were experienced baristas who were significantly below this variance.

I quoted this not for the content but for the mention of Aaron, who actually was one of the two people who convinced me to "experiment" with lower doses in the period just before I became a convert (the other person was Jim Schulman). I met up with Aaron in Vancouver where he was (and I suspect still is) the "Director of Coffee" for Ethical Bean, a major Canadian "feel good" (fair trade/organic/what-have-you) coffee roaster with sales across the country.

Aaron, whom I had met previously several times on yearly trips to Vancouver, was most generous with his time, and during the tour he gave me of the facility, he told me how he had stopped drinking espresso for TWO YEARS because it had become such an over the top in your face beverage that he could no longer tolerate it. Then, on his honeymoon in Italy, he rediscovered espressos that were subtle and drinkable and balanced. His reasoning was primarily that they were using a lower dose of coffee, and his own experimentation later led him to resume drinking espressos but ones that were dosed in more "Italianish" proportions.

This encounter with Aaron was in the early summer of 2007, about a year and a half ago. When I returned home to Idaho I began experimenting with the lower dosing and the rest (for me) is history.

I think Aaron is one of the most understated yet most knowledgeable and pleasant people in the entire coffee industry. If you stumble onto this post Aaron, you have my heartfelt thanks for making a real difference in my enjoyment of coffee and espresso.

ken

Ken I appreciate the post. I've always tried to pull the flavor and balance through the intensity of the espresso before down dosing, but now dosing lower I can focus on the flavors without being drown out by the intensity.

I don't work with too many blends but I've found better espresso with less coffee so far with the ones I have worked with. Its a good starting place anyways.

Ken Fox wrote:I think Aaron is one of the most understated yet most knowledgeable and pleasant people in the entire coffee industry.

Could not agree more.

malachi wrote:Are you whacking or tapping or shaking the portafilter (while dosing or before distributing)?
I can pretty easily dose and distribute 14 grams in a LM ridget double and I use the Stockfleth's style distribution.
The key is to not shake or "settle" the grounds while dosing or distributing.

I've seen top baristas on YouTube doing this, persistently, and I was almost sure that this wasn't correct practice. Is this as generally incorrect as I think it is?

orwa wrote:I've seen top baristas on YouTube doing this, persistently, and I was almost sure that this wasn't correct practice. Is this as generally incorrect as I think it is?

It isn't correct or incorrect but rather a method of updosing. If attempting a standard or down dose it would most likely not be a good practice. As mentioned the key is consistent dosing and distribution for desired build result.

My criticism of the practice is not due to the fact that it allows consistent updosing. Updosing is in itself incorrect on many machines, since the geometry of the group doesn't leave enough room for the updosed, expanding puck. Rather, my criticism is due to my belief that not all grind particles settle equally upon knocking the portafilter, rather, this mainly causes the fines (in my understanding) to settle, contributing to the bitterness (again, in my understanding).

Some people knock the portafilter only to overcome the non-uniformity (gaps) in the initial grounds distribution, not to updose. I believe there exist better methods.

orwa wrote:Updosing is in itself incorrect on many machines, since the geometry of the group doesn't leave enough room for the updosed, expanding puck.

Sigh...
1 - updosing is neither correct nor incorrect... on ANY machine. It's simply a change in a variable - a way to get a different profile from a specific coffee.
2 - the puck doesn't expand until after extraction is complete. Feel free to search the 'net for the infamous perspex portafilter video if you like - but the expansion occurs after the 3-way releases pressure.

orwa wrote:Rather, my criticism is due to my belief that not all grind particles settle equally upon knocking the portafilter, rather, this mainly causes the fines (in my understanding) to settle, contributing to the bitterness (again, in my understanding).

As noted above, updosing in this manner is a way to create a different flavour profile.
This profile results from a combination of manner factors - including restriction of flow, increased volume of coffees, a coarser grind... and fines migration.

orwa wrote:Some people knock the portafilter only to overcome the non-uniformity (gaps) in the initial grounds distribution, not to updose. I believe there exist better methods.

To be honest - I've never heard of anyone knocking the portafilter AFTER distribution.
Seems like a bad and counter-productive idea. But probably worth experimenting with to see what happens. You never know.

People are talking about it, but I couldn't find it.

The effect of updosing on my machine is clearer with coarser grinds. When I updose using such a coarse grind (relative to my machine's quite-fine preference), the flow starts fast as expected, but very soon the puck develops an unbelievable resistance to water flow, not allowing me to proceed with the pull any further after only a few seconds. The internal mechanical stress (due to the expanding puck) is then apparent upon unlocking the portafilter, even if I did it immediately while taking precautions. Hence, I thought it was reasonable to assume that updosing like this was incorrect on my machine, as it consistently doesn't allow me to obtain a good extraction due to this design restriction.

I am a post dose thumper, but I also do little distribution beyond that. I dose while grinding into a LM ridgeless basket while moving the portafilter around so the doses throw along the perimeter of the basket instead of one big cone in the middle of the basket. I dose 14 grams which is below the rim of the basket (on most coffees). If there is a large mound or obvious lopsided distribution I will fiddle with it to level it off. I give the portafilter three thumps, no more, no less, onto my tamp stand. You are not driving nails so just three light thumps and it levels out. A light tamp and to the group you go. My grinder does very well and does not produce many clumps so I have no need to do any other distribution provided I dosed it into my basket correctly.

I have an Elektra A3 which is updose intolerable; it simply does not work with an updosed basket due to the design of the group. If I want more than 14 grams I go to a triple basket but even then I usually run around 18 grams. I am still somewhat shocked when I see people jam 20 grams into a double basket. But, if that is what you like, then enjoy it. Personally I like to play with the extraction space varying the dose and temperature to see what I can get. If changing pressures was easy I would play with that as well but varying the pump pressure on my machine is too much work. Sometimes I come up with a winner of a combination, other times I grimace and down the sink it goes, but if you never try, you will never know.

malachi wrote:2 - the puck doesn't expand until after extraction is complete. Feel free to search the 'net for the infamous perspex portafilter video if you like - but the expansion occurs after the 3-way releases pressure.

Chris, I searched the net, and I only find a lot of people--you in particular--talking about it. Is there a place where one can read more about it, and see the video?

orwa wrote: When I updose using such a coarse grind (relative to my machine's quite-fine preference), the flow starts fast as expected, but very soon the puck develops an unbelievable resistance to water flow, not allowing me to proceed with the pull any further after only a few seconds.

That's VERY odd.
Normal behavior is a slow flow that then increases -- not the reverse.

Something is wrong for sure. But without knowing more - it's going to all be guesswork.

Do you have the ability to create a video and share it with us?
I'd love to see the full process (from grind through extraction).

shadowfax wrote:Chris, I searched the net, and I only find a lot of people--you in particular--talking about it. Is there a place where one can read more about it, and see the video?

I think James Hoffman has a copy of the Spaziale video.
I don't have a copy.

malachi wrote:That's VERY odd.
Normal behavior is a slow flow that then increases -- not the reverse.

I've seen the same thing from time-to-time and attributed it to deferred fines migration, for lack of a better explanation.

malachi wrote:That's VERY odd.
Normal behavior is a slow flow that then increases -- not the reverse.

It is pretty common for lever machine shots to start with a little crema-less gush. It doesn't happen every time though, and I'm not sure what variable it is associated with...

Orwa, are you still using the KA Proline grinder? I recall that mine did poorly at relatively coarse grind levels. This might explain the result you are getting.

Regards, Henry

I don't have a deeper basket for my Professional, so sometimes when there is an excess amount of coffee in the usual double basket, the puck expands too much (which presumably happens through the extraction), getting "dynamically tamped" through the extraction process by pushing against the shower screen, causing that increased resistance to waterflow, which is supported by two observations: (a) Upon unlocking the portafilter it literally "jumps", and I no more can re-lock it in the group due to the expanded puck size and the lack of vertical clearance (b) The expanded puck shows a clear shower-screen print and a very noticeable rims that must've developed through its desperate expansion while confined in space within the group (the shower screen on the La Pavoni's is somehow like a basket of a narrower diameter that is mounted by an o-ring gasket. This leaves some vacant space at its perimeter for puck expansion, hence the puck rims). When this condition happens, the puck develops a high resistance to water flow dynamically through the extraction process, or this is what I think.

Henry's comment is meaningful since this is also customary of the KitchenAid Proline's grind. This grinder produces the whole spectrum of particle sizes from salt-like granules to "coffee dust" (verified by sifting), and should be given a category of its own that is between blade grinders and conventional burr grinders. I think that the cause with that grinder was due to the huge amount of fines produced gradually settling at the bottom of the basket through the first few seconds of the extraction process ("fines migration"?). In my opinion, this is a reasonable explanation for what is experienced with that grinder since its average particle size is very large compared to the amount of fines it produces, and hence the fines are far from being suspended (held firmly in place in the tamped cake in the basket) under the high pressure exerted through extraction. Moreover, this resistance development was always accompanied by horrible bitterness, which further supports the claim of a "fines wall" that used to form at the bottom of the basket.

The puck produced with that grinder never also came out as a single piece, which I believe was due to the non-homogeneity of the particle size distribution with respect to different puck layers (after the extraction is complete, which supports the theory of the fines migrating through extraction).

I don't use the KitchenAid anymore. It failed dramatically to produce a single drinkable shot. I have been using a first-hand 30-year-old hand-crank burr grinder that I inherited from my grandmother new for 7 months now. It's great. It features huge conical burrs machined from steel, of which the stationary burr is welded into the metallic hopper cone. It also features a fixed-end design with a centering shaft above the burrs, without holding the burr from the underneath using a ball bearing like most box-shaped hand grinders that I see on this forum. The grind setting is thus from above and is unfortunately stepped. However, since the lower end of the rotating burr axle is not loose, the grind is of much higher quality (and is much more repeatable) than the Zassenhaus.

hbuchtel wrote:It is pretty common for lever machine shots to start with a little crema-less gush. It doesn't happen every time though, and I'm not sure what variable it is associated with...

Since in a lever machine, you have to fill the group with brewing water prior to pulling the lever (either directly or via the loaded spring), the pressure of that column of water (supported by the boiler steam pressure in the case of a single-boiler machine like mine) may cause the hot brewing water to penetrate the fresh-grounds cake at low pressures. Penetrating the fresh cake at low pressures causes a conventional "black coffee" extraction that is emulsion-free (crema-free). This problem is usually associated with old-beans that no more have enough oils to secure them against this low-pressure penetration. Lever machines of this sort are inherently susceptible to this phenomenon with coarser grinds, even if the beans are fresh.

What about variance when grinding on time? Is it all that important to get exactly the same doze (weight or volume, 14 or 14.5 grams)? How much is the variance actually when not exchanging the coffee in the grinder for other coffee? What is the influence of weather, humidity, temp-changes on what ends up in the PF-basket?

Also, I hear a lot of people talk about different methods to get to a consistent shot. Did any of you ever get good shots from just 7 grams of coffee? I understand the 14-15 grams aim for some, but if you use a single cup basket and grind just 7 grams of coffee, there could be hardly enough coffee to tamp or distribute evenly. Isn't 7 grams just a theory thing and aren't people just using more than 7 grams for a single straight espresso?

When I meant in my post above that I sometimes cannot even fit the basket underneath the brewhead as there was not enough headspace I referred always to a single cup basket, never to a double basket. When I suggested that sometimes things work out, other times not I was referring not to the same procedure, but more like with some single cup baskets I cannot even use the NSEW grooming method and tamp as the PF will not fit anymore underneath my brewhead while with other baskets such as a double basket using the NSEW grooming method I have the feeling that I end up with way too much coffee (consistently for the same basket but too much).

Sjoerd Jan

I see, that it is very difficult, to make a good espresso, using single basket , from 7-9 g of coffee in it depending in the pf size.(I have two single pfs, one from Reneka, which takes 7g, while another of unknown maker, takes 9g).
When I put much coffee,I can't close the pf in place,while if I put the "correct" dose,when I see the puck after the extraction, I see holes at the corners,and tunneling of course,because I can't tamp well.
So,I insist on doubles.

Single baskets are very challenging. The shape is non-optimal for great extraction as a general rule.
It's not impossible - it's just hard.

orwa wrote:When I updose using such a coarse grind (relative to my machine's quite-fine preference), the flow starts fast as expected, but very soon the puck develops an unbelievable resistance to water flow, not allowing me to proceed with the pull any further after only a few seconds.

As has been touched on, I see this as a function of grinder consistency more than anything else. Another possibility is to check your brew pressure to see if it remains relatively constant throughout the shot. A third possibility, but unlikely after reading your posts, is some weird distribution.

While the single basket is not the optimal shape, I will take a well pulled single over a split double any day.
I learned to pull singles first and after I was proficient I moved to doubles. I tend to get more of a "natural" ristretto -- if you will, out of the single. The key on the single is staying away from any sense of updosing at all, and not over tamping like your trying to force a kilo of grounds into a pound space. (That would be quite the shot!). Other than that, it's practice, and more than anything else-- feel. After a while, whether single or double you will learn to feel the appropriate resistance for that particular espresso and it will become second nature.