Controlling shot extraction pattern

Beginner and pro baristas share tips and tricks.
Abe Carmeli
Team HB

#1: Post by Abe Carmeli »

When I watch the bottom of the basket during a shot, I can clearly see an extraction pattern. For the longest time it was from the basket outside perimeter to the center. No matter which tamper I used. This issue came up before, with no clear answer as to what is causing it. One hypothesis was that it had to do with the pattern of water exiting the shower screen.

Only after getting the M3 grinder, I finally figured out what that was. I am now able to control the extraction pattern and change it by changing my leveling/distribution technique. Here's how it works:

An extraction pattern from the outside in (where the center of the basket is the last to saturate) is caused by what I call Schomer's Crater. Schomer advocates to control dosing as follows: Overfill the basket, do your NSEW leveling/distribution, and then shave off the access coffee with a bowed finger sweep across the basket rim. This movement will leave the basket surface with a shallow crater. As you sweep to shave off the access, your bowed finger pushes the coffee down where at the center of the basket it now becomes more dense than in the perimeter. (my guess, no density study done). Whatever the cause is, that technique always results with the center being saturated last.

To avoid the above saturation pattern, and reach simultaneous and even saturation across the basket bottom, one needs to leave the basket surface level without Schomer's crater. Now, that becomes a problem when you are dealing with a basket like the standard 14 grams Faema, and you do not want to updose. Most grinders will end up with 17-18 grams of coffee in the basket after leveling.

Here's where the Versalab M3 grindermade a difference in my case: It delivers fluffier grounds than the Mini. Those grounds occupy larger volume in the basket than grounds out of the Mini. Leveling the surface leaves 14-15 grams in the Faema basket, and as expected, the extraction pattern is simultaneous saturation.

There may be a way to do the same thing with a standard grinder (have simultaneous saturation without updosing). Any ideas?
Abe Carmeli

papalatte

#2: Post by papalatte »

It's funny I've doing the same thing on my own. Today my Yurg. has come out fluffy ( don't know why ) Strange but there seems to be an interconnectivity between people.

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malachi

#3: Post by malachi »

Stockfleth's Move for distribution.
"Taste is the only morality." -- John Ruskin

Abe Carmeli
Team HB

#4: Post by Abe Carmeli » replying to malachi »

How is this going to solve the updosing problem? How do you dose with Stockfleth to get 14-15 grams and avoid a crater?
Abe Carmeli

ant

#5: Post by ant »

From what I can gather when observing stockfleths.mov-

It looks like both the dosing method and the distribution technique are circular. This (hopefully) results in an even density in the coffee puck before tamping. From my experience on a super jolly mazzer it seems to be quite consistent when grinding per shot. If I grind for several orders in the one go however, I lose consistency in how the grind falls from the doser and that throws out any consistency I have when practicing the stockfleth method. :oops: Anyone care to donate a robur to a pisspoor barista? :)
Anthony Lau

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malachi

#6: Post by malachi »

Abe Carmeli wrote:
How is this going to solve the updosing problem? How do you dose with Stockfleth to get 14-15 grams and avoid a crater?
What updosing problem?

A distribution method shouldn't be used for dosing purposes. It's purely for distribution.

I'm confused.

You dose as you dose (so dose 15 grams, say) and then you distribute as you distribute (in this case, as noted, in a rotational manner).

Stockfleth's seems (in my experience) to result in a more even density throughout the basket.
"Taste is the only morality." -- John Ruskin

Abe Carmeli
Team HB

#7: Post by Abe Carmeli »

malachi wrote: What updosing problem?

A distribution method shouldn't be used for dosing purposes. It's purely for distribution.

I'm confused.

You dose as you dose (so dose 15 grams, say) and then you distribute as you distribute (in this case, as noted, in a rotational manner).

Stockfleth's seems (in my experience) to result in a more even density throughout the basket.
If I dose 15 grams, the grounds do not fill up the basket. Stockfleth's as I see it counts on a basket filled up to the rim with a little mound above it. The 14-15 grams dosage, or any dosage that does not fill the basket to its rim, will make the circular leveling movement impossible, as your finger will not touch the coffee grounds at all.
Abe Carmeli

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barry

#8: Post by barry »

Abe Carmeli wrote:If I dose 15 grams, the grounds do not fill up the basket.
get a nuova simonelli double basket. that maxes out around 15 grams.

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malachi

#9: Post by malachi »

Abe Carmeli wrote:
If I dose 15 grams, the grounds do not fill up the basket. Stockfleth's as I see it counts on a basket filled up to the rim with a little mound above it. The 14-15 grams dosage, or any dosage that does not fill the basket to its rim, will make the circular leveling movement impossible, as your finger will not touch the coffee grounds at all.
1) What basket are you using?
2) Why is it critical for you to dose that particular amount?
3) Are you settling the grounds in some way (tapping or shaking the portafilter, etc)?
"Taste is the only morality." -- John Ruskin

Abe Carmeli
Team HB

#10: Post by Abe Carmeli »

malachi wrote: 1) What basket are you using?
All double baskets: L/M, Ridgeless, and OEM Faema.
2) Why is it critical for you to dose that particular amount?
I like some Ristrettos at that dosage. But this is more of a general question: How can you properly distribute coffee when your dosage does not fill the basket.
3) Are you settling the grounds in some way (tapping or shaking the portafilter, etc)?
Not for a 15 grams shot.
Abe Carmeli