Clumping and Tamping

[cai42]

Greetings,

Why doesn't tamping with the usual amount of pressure eliminate the clumping problem? It would seem to me that all that pressure should compress the ground coffee and eliminate the clumps.

Cliff Isackson

[HB]

The pressure of tamping is small compared to the pressure of 9 bar, so the problem isn't "squishing" the space between clumps. The problem is that clumps have variable size and density, resulting in uneven distribution of coffee. In other words, if you sliced a puck formed from clumpy coffee into perfectly pie-shaped wedges, the wedges would not weigh the same.

[Randy G.]

Dan said: "The pressure of tamping is small compared to the pressure of 9 bar..."
A 35 pound tamp with a 58mm tamper is only 8.75 pounds/sq. in. of pressure on the coffee.

...and why doesn't the last post in a thread have a "Quote" button.. Quite inconvenient.. or is it just at my end?

[HB]

...and why doesn't the last post in a thread have a "Quote" button.. Quite inconvenient.. or is it just at my end?

Follow-on discussion split/merged to Last post does not have "quote" option.

[malachi]

Tamping is purely intended to preserve your dream "perfect density" bed of coffee.
Using pressure to create this "perfect bed" from uneven distribution is somewhere between challenging (and requiring far more power than a human is likely to be able to exert) and simply impossible.

[Eric]

Tamping is purely intended to preserve your dream "perfect density" bed of coffee.
Using pressure to create this "perfect bed" from uneven distribution is somewhere between challenging (and requiring far more power than a human is likely to be able to exert) and simply impossible.

How would you characterize the importance of tamping? Does it do much useful beyond mashing the grounds below the shower screen if the initial distribution is good?

eric

[cannonfodder]

Tamping is important, but less critical than distribution and dose in my opinion. A good tamp is the icing on the cake. It will not make a bad distribution or dose any better but a bad tamp can destroy a good dose and distribution. It simply helps to ensure an even density devoid of, well, voids. Light tamp, heavy tamp, does not matter just as long as it is consistent.

[cai42]

Greetings,
Do baristas in a competition mix the ground beans with needles, pins, and other pointed objects? If not, why not?

Cliff Isackson

[Marshall]

This isn't mentioned very often, but a firm tamp allows you to turn the portafilter over and shake off loose grounds around the collar, instead of bumping it with the tamper and unseating the puck.

[Marshall]

Greetings,
Do baristas in a competition mix the ground beans with needles, pins, and other pointed objects? If not, why not?

Cliff Isackson

No. The judges would laugh themselves silly and forget to take notes.

[cafeIKE]

This isn't mentioned very often, but a firm tamp allows you to turn the portafilter over and shake off loose grounds around the collar, instead of bumping it with the tamper and unseating the puck.

Assuming one does a screen flush and wipe prior to pulling the subsequent shot :

Other than offending the sensibilities of an OTT neat freak, these stray ground do what?
Are they driven at warp speed into the polished puck surface, divoting a moonscape from which channeling canals form?

Worrying about a few milligrams of loose coffee is one more internet idiocy learned, evaluated, rejected and consigned to the dustbin, taking its rightful place with 30# tamps, tip-tapping, puck polishing...

(Please don't take offense, Marshall. This is directed at the community at large)

[HB]

Do baristas in a competition mix the ground beans with needles, pins, and other pointed objects? If not, why not?

Because they're using better grinders. I have a Mazzer Mini, Super Jolly, and Robur. The difference in the evenness of the extraction post-WDT is dramatic for the Mini, notable for the Jolly, and nearly indistinguishable for the Robur.

Other than offending the sensibilities of an OTT neat freak, these stray ground do what?

I asked Matt Riddle, former USBC winner, the same question during an impromptu barista lesson at the Barista Guild booth. He said knocking down the grounds may keep the group area cleaner, nothing more. I agree and don't tap with the tamper or worry about a few milligrams of stray grounds. Swipe the basket lip and move on. If you really want to flip the portafilter, well, I guess it's a nice flourish.

[Marshall]

Assuming one does a screen flush and wipe prior to pulling the subsequent shot :

Other than offending the sensibilities of an OTT neat freak, these stray ground do what?
Are they driven at warp speed into the polished puck surface, divoting a moonscape from which channeling canals form?

Read carefully. I said shake grounds off the collar. It's a simple step to keep the brewhead cleaner, where the ears of the collar push stray grounds, and, yes, I do flush (and brush) after each shot.

It's a habit I picked up from ( name drop alert ) Heather Perry.

[Randy G.]

I agree and don't tap with the tamper or worry about a few milligrams of stray grounds. Swipe the basket lip and move on.

I have just covered this subject as part of my newest "Lesson #12" on my website. I have abandoned tapping the portafilter. What I do, FWIW, is after tamping I quickly remove the tamper from the basket. This creates a partial vacuum under the tamper pulling loose grounds on the outskirts of the tamper back onto the tamped coffee. Then I light tamp again. Whatever doesn't get dislodged and tamped can happily stay right where they are, and in punishment I will blast them shortly with water at around 200 F for their insolence.

Any coffee on the lip of the basket or the ears I brush off with my hand just before locking the PF for the pull.

And I agree that a lot of lore gets passed down and is put to use by new home baristas who, out of habit, continue to use the procedures without thought, and they become habit. I am trying to break myself of as many as possible as they are recognized.

[RapidCoffee]

The judges would laugh themselves silly and forget to take notes.

Apparently some folks are more easily amused than others.

[cafeIKE]

Read carefully. I said shake grounds off the collar.

I thought the 'collar' referred to the thin ring of ground at the edge of the basket not compressed by the tamper. First time I ever heard 'collar' used to describe a part of a portafilter...

[cai42]

Greetings,

I have a short history in espresso brewing so I don't know if the clumping and distribution concerns have always existed. What affect did the naked portafilter have on this problem? If the naked portafilter didn't exist would we be as concerned about even distribution?

Cliff Isackson

[Marshall]

Greetings,

I have a short history in espresso brewing so I don't know if the clumping and distribution concerns have always existed. What affect did the naked portafilter have on this problem? If the naked portafilter didn't exist would we be as concerned about even distribution?

Not "as" concerned, but it was still understood that a shot that turned paler and lost its viscosity after 10 seconds had a channeling problem.

[HB]

Not "as" concerned, but it was still understood that a shot that turned paler and lost its viscosity after 10 seconds had a channeling problem.

Clumping and distribution problems have always existed, the bottomless portafilter just made their effects blatantly obvious.

I use a bottomless portafilter because it's less mess at home, but rarely on the La Marzocco at our Friday get-together at Counter Culture. If you taste all the espressos you make -- even the bad ones -- you'll learn to recognize taste defects associated with channeling and the diagnostic value of the bottomless portafilter is reduced. One disadvantage of bottomless portafilters is that some are distracted by the process and lose focus on taste; the thread The goal is great TASTING espresso, not great LOOKING espresso elaborates on this point.

[cai42]

Greetings once again,

The years before the naked portafilter's appearance most of us were satisfied with the espresso we made at home. The only remedy we had was to adjust the grind and maybe some adjustments to the espresso maker to improve the shot. Along comes the naked portafilter and with that hundreds of forum posts telling us what this was the tool to tell us what was wrong with our shots. But we were enjoying our shots, some were good, some were great, and some were bad. Now we are spending more time with our head tilted and video cameras aimed at the group and watching coffee drip from a basket into a cup. What was fun to make and drink now became a science project.

I think the process is now more important than enjoying the product.

Cliff