Hi All..Need expert advise...should I go for flat or convex? Any difference at all? Thks.

Skip the Espro and get a regular tamper, either shape. If you don't like it, get the other shape. No need to spend a fortune on the tamper, and eventually you will probably end up with several anyway.

Convex. For me anyway, it made a noticeable difference over using the flat. Since I got it, about a month ago(ish), Ive had maybe 2 or 3 shots that had any sidewall channeling.. Tamping is more or less, to "preserve" the good distribution of the grounds in the basket. A flat tamper does that, I believe a convex does it better.

If you cant decide, do what I did.. By one of each on the cheap. Rattleware and EspressoGear both have tampers under thirty bucks.. Rattleware is flat, EspressoGear offers Convex.

The convex piston specifically is probably good. Coffee grounds are essentially incompressible beyond a certain point. The convex piston directs the greatest pressure toward the center of the basket, resulting in a uniform distribution of pressure in the surrounding area.

Here is a little experiment for you to do. Get a tennis ball. place it on the table. Okay, the contact point is in the center of the bottom, right? Now rotate the tennis ball by 30 degrees. OMG! The contact point is still in the center of the bottom! Now, try it with something flat, like a dinner plate. Notice how even a slight tilt to the dinner plate results in asymmetric pressure application?

Okay, that is kind of an extreme example, but basically this is part of what is going on. The goal of tamping is to press down very uniformly with an even pressure distribution. The convexity allows us to compensate for errors in our technique, to some extent. If you have weaknesses in your technique that this can compensate for, then you will prefer the convex piston. If your technique is stellar in this regard, you will probably not notice a difference.

And honestly it has been my experience that the difference that tamper bottom shape makes is subtle and for the most part not directly on the extraction. Maybe if you had an automatic tamping machine with a flat and a convex piston, you could assess this, but there are so many other variables that come into play, this detail is just minimal.

What I think is important is how the shape of the tamper piston (or in fact the shape of the tamper in general) will affect your technique for tamping. It is my experience that the most important aspect is to be able manipulate the tamper very easily, as if it were simply and extension of your hand. If you have absolute control over the tool, you can be more accurate, and your tamp will be more consistent. THAT is really the key: consistency.

So pick whatever tamper feels best for you in terms of weight, shape, size, etc. and learn to use it.

I have bought an ESPRO flat, based on my personal preference, and the idea of a uniformly compressed grounds. With convex, I feel, the grounds in the middle are compressed more than those on the outer rim. So the channeling might occur there. But that is just my feeling, and I think it is more of a personal decision.

Vad wrote:I have bought an ESPRO flat, based on my personal preference, and the idea of a uniformly compressed grounds. With convex, I feel, the grounds in the middle are compressed more than those on the outer rim. So the channeling might occur there. But that is just my feeling, and I think it is more of a personal decision.

I liked using my Espro Click tamper to learn what 30 lbs felt like. As a beginner I think it help re-enforce how much pressure to apply. I now use a RB flat base with a custom Bacote handle by Dave Stephens. Life is good, time to have my afternoon espresso!

Mark

I have owned both Espro Flat and Convex. I prefer the convex. Only reason is feel.... and perhaps a little more room for the bolt head in the center PF.

Now for some myth-busting.....

I don't understand why people say the Espro is a trainer or beginner tamper. It's one of the best made and well balanced tampers around. Period. WBC competitors use it too. You can go lower then 30 lbs or more if you like. It won't stop you. The click is only a indicator.

I own a convex Coffeelab tamper as well but still find myself preferring the Espro for it's feel.

Is it overpriced as some claim? I don't think so....especially considering it's one of the few that is actually more than just a lump of metal.

Thks for all the great replies Guys..I asked the same questions to my barista trainer friend and his reply was "...not really unless you are making large amount of coffees... then go convex, it's a bit more consistent when you cannot put all the attention necessary into the shot. I always go convex but that's just a thing of mine, I know great Baristas that would never touch one. At the end of the day it won't really matter, go with your gut instinct. Keep at it, the consistency of the shot is always the biggest challenge..."
So my final decision is go for convex

Which should I go for? I only have budget for one. My barista trainer friend said " If you want to know what 15 kg feels like you can use a regular house scale to tamp on. Try a few time and you'll get the idea of how much weight you need to put on it. I have been testing the theory of 15kg (30lbs) of pressure and frankly, as long as you get over 13 kgs and less then 20 kgs and you tamp with direct downwards force there is no really discernible difference. I have been testing this thoroughly over the years.
The Espro tamper is a great training tool if you train others (i have one) or you have a cafe with many employees that require guidance and consistency in tamping... but if it is for personal use, you can get much nicer looking tampers for that price if you buy a $20 scale instead."
All comments and advise greatly appreciated...

It's perfectly fine with me...thks Boss

Spend the money on coffee. The best training tool is..... practice.

If you want to get an immediate sense of what is happening with your tamping, get a bottomless portafilter....

Cheers

Mike