Does a good center tamp take care of the sides?

Beginner and pro baristas share tips and tricks.
buzzword

#1: Post by buzzword »

If you've got a tamper like the RB convex american base, with the milder, shallower curve to the bottom, what do you do about the sides of the PF?

Do the sides take care of themselves with a good center tamp? Or if side tamps are needed, is the tamper still best held perpendicular to the PF as for the main tamp, or can you tilt, cant, the tamper into the 4 poles fairly gently and get a better pack?

Same question with the RB Euro base, deeper curvature: what is good to do for a well-packed side?

Greg

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HB
Admin

#2: Post by HB »

Your question reminds me of an exchange with the Macap auto-tamper product designer at the SCAA conference.

Image

We were discussing some potential improvements to their products. I commented on the auto-tamper, which comes with a 56.5mm and 53mm piston. A gap of over a millimeter all away around? Why not make the disk larger to knock down the stray grinds during the compression stroke and better seal the edges to prevent side channeling? He claimed that compressing all the way to the edge was unnecessary and a larger disk wouldn't reduce channeling one wit.

I offered to test his claim and report back, but forgot about our exchange until I read your post. The auto-tamper is on the kitchen countertop tonight as a reminder to give it a whirl this week.

On a related note... during last year's SERBC judge certification workshop, the trainer mentioned the importance of knocking the side of the portafilter to dislodge stray grinds. Being an inquisitive imp, I queried what taste fault we might note if the competitor neglected this step. He asserted that an ashiness could result as the loose grinds were subjected to a higher temperature for a longer period than those packed tightly together. (Sounds like a dubious claim to me; I would have accepted a response along the lines of "Hmm-m, good question, I'm not sure" without comment).

My remarks above don't respond to your question. But according to said Macap engineer, the answer is yes. According to a WBC certified trainer, the answer is no. Anyone else among the HB membership care to proffer a better answer to the question: Does a good center tamp take care of the sides?
Dan Kehn

Abe Carmeli
Team HB

#3: Post by Abe Carmeli »

Dan,

This is a side note. I have found that the best usage of the Macap Auto Tamper is using Staub. I'm surprised its designer did not bring it up. The 56.5 mm piston is just perfect for it. I could never get better Staub tamps hand tamping. But that of course has nothing to do with the experiment at hand :).
Abe Carmeli

Abe Carmeli
Team HB

#4: Post by Abe Carmeli »

buzzword wrote: Do the sides take care of themselves with a good center tamp? Or if side tamps are needed, is the tamper still best held perpendicular to the PF as for the main tamp, or can you tilt, cant, the tamper into the 4 poles fairly gently and get a better pack?
I use Staub to tamp, and rarely ever see any channeling. Staub eliminates the need to tap the side of the P/F, which may cause channeling. But to answer your specific question, in a recent jam session with Ken Nye, I noticed that he is experimenting with a new move to tuck in the sides. He rotates the edges of the tamper around the rim after the tamp. I have not experimented with that method.
Abe Carmeli

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HB
Admin

#5: Post by HB »

Abe Carmeli wrote:I have found that the best usage of the Macap Auto Tamper is using Staub. I'm surprised its designer did not bring it up.
Actually I mentioned the Staub tamp and the problems the portafilter rest presents. For example, the Cimbali portafilter has a perfectly flat bottom (good), but wide spout (bad). Even with the spout removed, the fork isn't deep enough to allow for tamping the "south" Staub. The La Spaziale S1 portafilter is smaller and the bottom is tapered. Although the auto-tamper does accommodate it, you must watch the cant very carefully because the fork doesn't assure levelness front-to-back.

On the other hand, chopping all these portafilters to bottomless makes for an idea auto-tamping surface, if that's your thing. I run hot and cold on the Macap auto-tamper. It's great for those times I want to be absolutely certain of a consistent tamp (e.g., when testing grinders). Otherwise it takes up too much countertop space given that I'm pretty happy with my own tamping consistency.
Abe Carmeli wrote:But to answer your specific question, in a recent jam session with Ken Nye, I noticed that he is experimenting with a new move to tuck in the sides. He rotates the edges of the tamper around the rim after the tamp.
Jim mentions that technique in his article (link):
  • Stronger baristas may use heavier tamps, while some use a nutating motion (rolling the tamper in a motion like a flipped coin settling) to accentuate the pressure towards the edges of the basket. An alternative to the nutating motion is using a convexly curved tamper, which accomplishes the same thing.
BTW, for weeks now I have been trying in vain to work "nutating motion" into casual conversation. ;-)
Dan Kehn

Abe Carmeli
Team HB

#6: Post by Abe Carmeli »

HB wrote:Actually I mentioned the Staub tamp and the problems the portafilter rest presents. For example, the Cimbali portafilter has a perfectly flat bottom (good), but wide spout (bad). Even with the spout removed, the fork isn't deep enough to allow for tamping the "south" Staub.
I've stopped tamping into the P/F. Not because of problems with the Macap, but because I do not see any advantage doing it in a home environment. I tamp directly into the basket. As to the Macap, I bought a small 1/8" thick stainless steel plate and I rest it on the top of the fork. I put my tamping mat on it, the basket on top of the mat and tamp.

I still tamp by hand every other week, just to keep my tamping skill limber.
BTW, for weeks now I have been trying in vain to work "nutating motion" into casual conversation.


Now, aren't you happy we've had this discussion :wink:
Abe Carmeli

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malachi

#7: Post by malachi »

In my opinion, tamping is perhaps the most over-emphasized of all techniques.

There are two goals when tamping.
1 - preserve distribution,
2 - create sufficient resistance to water pressure.

It seems to me that many people attempt to use complicated tamping techniques to address deficiencies in other techniques (namely dosing and distribution).

With the correct sized tamper, I've seen no increase in channeling when simply tamping "in the center" over any complicated tamping method and, in fact, find far greater consistency in the extraction (flow, volume) when using the "standard" tamp style.
"Taste is the only morality." -- John Ruskin

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OlywaDave

#8: Post by OlywaDave »

I'm gonna have to go ahead and agree with Malachi here. Dosing and distribution are probably the most important factors in preparing for your espresso extraction. While the tamp pressure and technique do matter to some degree if your coffee is not properly ground, dosed and distributed in the portafilter basket the technique is all for nothing.

We all should know what a properly dosed basket feels like versus not dosing enough or even dosing too much, that is the key. On my EPNW tamper I see little to none of the tamp piston's vertical sides when tamping and polishing. Below is a hastily illustrated diagram of what I mean.
Image
David White
EspressoParts.com

buzzword

#9: Post by buzzword »

I appreciate the attention to the question. Since I really am new and don't know anything, I'm caught between shutting up on the one hand and saying things un-useful and lowering the s/n of the site.

Dan wrote:
Your question reminds me of an exchange with the Macap auto-tamper product designer at the SCAA conference.

We were discussing some potential improvements to their products. I commented on the auto-tamper, which comes with a 56.5mm and 53mm piston. A gap of over a millimeter all away around? Why not make the disk larger to knock down the stray grinds during the compression stroke and better seal the edges to prevent side channeling? He claimed that compressing all the way to the edge was unnecessary and a larger disk wouldn't reduce channeling one wit.
Seems like unless the fit of the tamper in the PF is perfect, there will be diminished compression on the edge somewhere. I don't have any sense of how much difference that would make.

For a flat tamper, I picture the compression/density increasing, around the circumference, in basically linear fashion, from the bottom edge of the tamper to somewhere on the side of the PF; a conical section of higher density, with the top of the cone almost exactly the same size as the tamper. That would, I'd think, leave some less-compressed coffee in a circumferal wedge (thickest end on the surface of the cake). A picture would be good.

The apparent best tamp would have the minimum wedge of less-compressed coffee.

A convex tamper would create a different pressure configuration, maybe a buldging conical section, because the tamper exerts true lateral pressure near the top of the coffee, where the flat tamper exerts a kind of inferential lateral pressure only. Added lateral pressure should mean increased compression to the circumference.

Then malachi wrote:
In my opinion, tamping is perhaps the most over-emphasized of all techniques.

There are two goals when tamping.
1 - preserve distribution,
2 - create sufficient resistance to water pressure.
So even if my intuition were somewhat true, malachi's words say that it just doesn't matter much, and I believe him.

In so far though as good extraction requires consistent compression, the question of "what happens with a center-only tamp" seems to partition a useful component of the question space.

So I'm glad you're going to exercise the Macap, Dan. Thank you.

King Seven

#10: Post by King Seven »

I've been using the MACAP auto tamp thing for a while as we sell it in the UK.

Great in theory but we've asked for a few modifications - wider tamper, convex base, a decent clean smooth base to the tamper (at the moment it collects A LOT of coffee grounds) and for the tamper to be fixed and not swivel.

I like the idea - and it's very close to being a useful tool.