Convex tamper and NSEW technique

#1: Post by **Dogshot** » February 28th, 2006, 11:17 pm

I recently changed machines, from a Gaggia Classic to a Brewtus II. My flat-based Reg Barber was great with the Gaggia, but I was getting pin-holes near the centre of my pucks on the Brewtus (because of the the convex shower screen?).

So I pulled out the pos plastic tamper (which is convex) that came with the Brewtus, and I use the flat-based Reg to do my NSEW and the pos convex plastic to do my 30lb tamp. Now, I am using the Weiss Distribution technique, and getting pucks with zero evidence of channeling maybe 30% of the time, so I am very happy with the results. In the interest of parsimony, however, I would prefer not to use 2 tampers when building a puck, but the pos cannot be used to do a NSEW tamp that works.

My question is, will a Reg Barber convex tamper permit a good NSEW tamp? If not, how do you use a convex tamper?

Thanks,

Mark

#2: Post by HB » March 1st, 2006, 12:09 am

My flat-based Reg Barber was great with the Gaggia, but I was getting pin-holes near the centre of my pucks on the Brewtus (because of the the convex shower screen?).

Pinholes? Like little geisers? That points to a more serious disruption of the puck integrity than a convex tamper would solve.

Dogshot wrote:Now, I am using the Weiss Distribution technique, and getting pucks with zero evidence of channeling maybe 30% of the time, so I am very happy with the results.

For those who are scratching their heads saying "who is Weiss?", I believe it refers to RapidCoffee's stirring with a pointy implement:

Tracing circles in search of better distribution (link)

I do the NSEW tamp, but it's about pushing down the grinds adhering to the perimeter and an extra measure of side-seal pressure (sometimes I think it's overkill; it's a habit for me now). Since the tamper is 58mm and the basket is just a teenie bit bigger, I don't fuss about the minuscule irregularity the convex surface might induce for being offset 0.5mm offcenter (it'd be another story if the tamper was 53mm and the basket was 58mm).

More directly to your question, Reg sells two different curved bases: The American and the Euro curve, the latter's curve being much more pronounced. I would have to check, but I'm fairly certain the EPNW convex bases are even more curved than Reg's Euro. I collect tampers and yet I don't change my tamping style depending on the tamper piston's shape.

#3: Post by **RapidCoffee** » March 1st, 2006, 12:53 am

Dogshot wrote:I recently changed machines, from a Gaggia Classic to a Brewtus II. My flat-based Reg Barber was great with the Gaggia, but I was getting pin-holes near the centre of my pucks on the Brewtus (because of the the convex shower screen?).

So I pulled out the pos plastic tamper (which is convex) that came with the Brewtus, and I use the flat-based Reg to do my NSEW and the pos convex plastic to do my 30lb tamp. Now, I am using the Weiss Distribution technique, and getting pucks with zero evidence of channeling maybe 30% of the time, so I am very happy with the results. In the interest of parsimony, however, I would prefer not to use 2 tampers when building a puck, but the pos cannot be used to do a NSEW tamp that works.

My question is, will a Reg Barber convex tamper permit a good NSEW tamp? If not, how do you use a convex tamper?

Thanks,

Mark

Hi Mark! I've got one flat base and one convex base tamper (oh yeah, a flat base Espro too

), and I find the convex base to be slightly more forgiving. This was true on my Rancilio L7 (flat shower screen) as well as my Vetrano, so I don't think it's just the shape of the shower screen.

I like to play around with different tamping styles, but a simple one works as well as anything for me: tamp in the center, brush off rim and invert PF to remove excess grounds, then tamp hard (I tend to use over 30#) in the center, rotate with no pressure to polish.

HB wrote:For those who are scratching their heads saying "who is Weiss?", I believe it refers to RapidCoffee's stirring with a pointy implement...

Um, I think Mark coined the name. And the pointy implement would be a dissecting needle. See the link for more details.

Not many people have dissecting needles lying around, so (with Dan's permission) I'd like to offer one to any HBer who wants to give this a try. I just ordered several dozen (they're very inexpensive). I'll be glad to mail one to anyone who sends me a self-addressed stamped envelope. Until they run out, anyway. Just my way of saying thanks to the community. Dan, is this OK with you?

- John

#4: Post by HB » March 1st, 2006, 1:02 am

RapidCoffee wrote:Dan, is this OK with you?

Absolutely! Although every time you write "dissecting needle", I have flashbacks to high-school biology class (ewww-w), hence why I continue to refer to it in a more circuitous fashion.

#5: Post by **JonR10** » March 1st, 2006, 7:10 am

HB wrote:...hence why I continue to refer to it in a more circuitous fashion.

I think it should be marketed as The Weiss Distribution Tool

I love mine

#6: Post by **jrtatl** » March 1st, 2006, 10:26 am

RapidCoffee wrote: Not many people have dissecting needles lying around,

I use a toothpick for this, and it seems to work great. No needles required.

YMMV.

#7: Post by **k7qz** » March 1st, 2006, 11:35 am

jrtatl wrote:I use a toothpick for this, and it seems to work great. No needles required.

YMMV.

I use one of my wife's stainless steel crochet hooks. It's about the same diameter as a dissecting needle (all my old gross anatomy dissection tools still smell like formaldehyde...). The handle end of the crochet hook is rounded so it doesn't scratch the PF basket and it has a little flat grip in the middle to hang on to. I also found the "yogurt cup" variation used in the aforementioned link keeps the loose grounds from getting knocked out of the basket when stirring.

FWIW, this is a really slick trick. I use a Mini E grinder primarily at home and a Rancilio Rocky DL at our vacation home on the coast. I never was totally happy with the Rocky compared to the Mini E as Rocky's distribution in the basket seemed "clumpy" and uneven to me compared to the E. The "Weiss technique" solved this problem perfectly! So if you guys haven't tried it yet, I think you'll like it!

Oh, BTW, don't tell my wife I'm using her crochet hook- she hasn't missed it yet!

-Mike

#8: Post by **RapidCoffee** » March 1st, 2006, 11:42 am

HB wrote:... every time you write "dissecting needle", I have flashbacks to high-school biology class (ewww-w), hence why I continue to refer to it in a more circuitous fashion.

Yeah, I know! But I have tried other pointy things (like toothpicks), and they didn't work nearly as well for me. I'm sure that anything thin and pointy will work as long as it's comfortable to hold. A dissecting needle fits the bill very well.

Dan was kind enough to set up a forwarding address: rapidcoffee@home-barista.com. Email me requests with "Weiss Distribution Tool" in the subject line, and I'll reply with an address to send your SASE. I've got several dozen dissecting needles on order; they should arrive in a week or so. I'll repost when (if) supplies get low so that nobody wastes stamps.

Please do refer to the link mentioned above for further details. The use of a funnel is important to keep the grounds in the basket while you stir, otherwise you may get the dosing inconsistencies that Dan reported. A yogurt container with the bottom cut off works well. (But you're on your own there. I like yogurt, but not that much.

)

Of course feedback is welcome, along with any new variations on the technique (such as Dan's concentric circle stirring pattern).

- John

March 2nd, 2006, 11:55 pm

I think I'll go for it and order an RB convex tamper. The pos plastic one that came with the Brewtus II is the European (more aggressive) convex design, so that's the route I will go. The success I am having lately is undeniable - shots look great, taste better than ever, and the pucks are amazing.

Borrowed from the flat vs convex thread:

malachi wrote:Honestly, with good technique I've seen no real difference (either observed with the naked portafilter or tasted in the cup).

I have tried to get the same results with the flat base tamper, and at their best, the shots are not as good as I get with the convex, and consistency (in terms of puck surface cosmetics and taste) also takes a hit. I'll defer to experience, and keep trying with both, but my results so far are pretty clearly in favour of the convex.

#10: Post by **shadowfax** » March 3rd, 2006, 2:50 am

Dogshot wrote:I have tried to get the same results with the flat base tamper, and at their best, the shots are not as good as I get with the convex, and consistency (in terms of puck surface cosmetics and taste) also takes a hit. I'll defer to experience, and keep trying with both, but my results so far are pretty clearly in favour of the convex.

I suspect that the idiosyncratic and inexperienced techniques that us amateur home-baristas develop probably tends to favor one tamping surface or the other a lot more than the technique of a bona fide demigod of coffee production...