# Flat vs convex tamper



## hilltopbrews (May 17, 2013)

Hello all

i am looking for 58mm tamper for gaggia classic. I noticed the term flat and convex. I was wondering what is the difference (apart from the obvious)? What are the pros and cons of convex tamper. Does the shape of the tamper matter? I've only had a flat 54mm tamper.

thanks


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## charris (Feb 17, 2014)

Better to get a 58.4mm tamper. At least for VST baskets it is much better, I will also check if it fits the standard gaggia double basket.


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## pedro88 (Nov 26, 2014)

What would be the best tamper for triple shot bottomless portafilter +gaggia classic?


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## hotmetal (Oct 31, 2013)

I measured up my tampers and baskets for Bigpikle and can confirm that a 58.35 or 58.4 work for the VST 18g and the stock Gaggia double. Much better than a 58 ( though I did discover that my '58' actually measured 57.4)! I'd have thought this would work just as well on a triple.

As I understand it (i.e. vaguely!) Flat bottomed tampers like my 58.35 Knock Heft are not so good if your tamp style involves nutating. However I prefer to tamp straight down and give a quick twist to polish so it suits me. The other shapes are variations on a theme where the idea is to force some more coffee outwards from the centre to seal the edges better. Or at least that's what I thought, but happy to be corrected if I'm wrong about that.


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## emradguy (May 24, 2014)

Tamper bases come in several designs, including flat, euro curve, American curve and beveled. There are also ridged variations of each. I think most of what is said on the street about which is best is malarkey. However, a few tenets come to mind. Prior recommendations typically said you should get one that matches the shape of your shower screen. I've never seen a curved shower screen. I've not seen curved baskets either. The curved and beveled bases were designed to help prevent/correct edge channeling (aka donut shots). Just about everyone I "know" recommends a flat tamper base for VST baskets. I've found that to be good advice...ie, in my experience, flat bases work best with the VST baskets. Regarding size (something you didn't ask about, but was mentioned anyways)...yes, the VST baskets take a 58.35mm tamper base. The basic principle is you want the base diameter to be as large as possible, without binding on the basket wall. I couldn't tell you what the Gaggias take, or even if they're made with enough precision that you can take someone else's measurement to the bank. If you can spare the money, get yourself a VST in the size you use most often and then pick up a 58.35mm tamper. You'll be glad you did.


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## charris (Feb 17, 2014)

Are we sure that a flat 58.4 works better than a convex one with VST? I just got a convex goldfinger base the opinion of most people here prefering that vs the flat one


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## coffeechap (Apr 5, 2012)

charris said:


> Are we sure that a flat 58.4 works better than a convex one with VST? I just got a convex goldfinger base the opinion of most people here prefering that vs the flat one


You also have a 58.55 flat Harris


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## jeebsy (May 5, 2013)

We did until St Perger came along with his new clothes


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## charris (Feb 17, 2014)

coffeechap said:


> You also have a 58.55 flat Harris


For sure Dave. When should I use the goldfinger do you think?


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## coffeechap (Apr 5, 2012)

It will come down to preference, I still love using my convex with the l1, and with the ims baskets


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## emradguy (May 24, 2014)

charris said:


> Are we sure that a flat 58.4 works better than a convex one with VST? I just got a convex goldfinger base the opinion of most people here prefering that vs the flat one


I'm sure that I prefer a flat tamper with my VST baskets. The posts I've read on Home-Barista and CoffeeGeek report the same thing. Perhaps people on this forum and the other forums I don't visit feel differently?


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## Mrboots2u (May 10, 2013)

Personal preference flat with vst baskets for me


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## Firochromis (Oct 26, 2014)

What about IMS baskets? Convex wins this time?


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## Xpenno (Nov 12, 2012)

Flat and properly sized for your basket will make your life a bunch easier


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## urbanbumpkin (Jan 30, 2013)

I've got a flat, trapez convex and a flat2convex. I was 100% convex till about 24 hrs ago.

Agree with Spences point on getting one that fits the basket.


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## MrShades (Jul 29, 2009)

Using my new convex Goldfinger with VST and it's fan-bloomin-tastic!

I was a flat/Plano-convex fan, but Dave only had a convex base when I bought my first Torr and they've been working well for me ever since. Very happy with the Goldfinger indeed.


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## simonp (Nov 18, 2014)

Flat 58.4mm tamper with a VST basket for me too. With other baskets I tied flat and convex and did not find really any difference to the shot but found the flat easier to judge a level tamp with. My 58mm convex tamper base was horrible with the VST basket, channelled like nobody's business round the sides...


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