Hi there,

When I create an even bed of coffee prior to tamping either I get a doughnut extraction or the flow merges to the center of the basket at the very end of the pour.

However I noticed that when I dig a little hole in the middle of the coffee puck while WDT I have much nicer pours.

I'm using a 58,35mm flat tamper combined with a 18g VST basket.

Any other members have experienced something like this? Would that mean that a convex tamper would be more appropriate for my equipment?

Thanks

Yes.

That is not un-common and probably happening in baskets all over, only they have spouts and no one notices. WDT seems to solve this for me using VST baskets and tamp. Maybe the sloped sides of some baskets mitigate the fact that the center of the puck is more dense.

I don't think a convex tamp would help much, but that opinion is just from reading a limited amount of other's experience with them.

I have a flat 58.35mm and a convex 58mm tamper. When I tap to a level surface, I get more even extractions with my convex tamper. I use VST and Strada baskets and it's the same in both.

Bunkmil wrote: However I noticed that when I dig a little hole in the middle of the coffee puck while WDT I have much nicer pours.

I've had the same experience. Only difference is I'm nutating in a 49mm basket. Using a convex or flat tamper doesn't seem to make much of a difference but I use a convex because, why not?. Doughnut extractions are now a thing of the past.

My experience with convex is that it makes prettier but not necessarily tastier extractions. A better distributed flat tamp seems to taste better.

Reducing your dose a little often helps with the issue.

Bunkmil wrote:Hi there,

When I create an even bed of coffee prior to tamping either I get a doughnut extraction or the flow merges to the center of the basket at the very end of the pour.

However I noticed that when I dig a little hole in the middle of the coffee puck while WDT I have much nicer pours.

I'm using a 58,35mm flat tamper combined with a 18g VST basket.

Any other members have experienced something like this? Would that mean that a convex tamper would be more appropriate for my equipment?

Thanks

My experience has been that a slightly concave bed of grounds tamped with a flat tamper works well with my VST 18g. See Mark Prince's review of VST baskets from a few years back here in which he gets a slight central depression by sweeping with a Scottie Tools dosing card.

That technique looked like too much work for me. I've found it quicker to dose into an OE Ipanema cylinder and WDT with a cocktail whisk leaving a slight depression of grounds in the center. Then a couple light settling knocks on the counter, remove the dosing cylinder and tamp with flat tamper.

This is a very good idea. Thanks for the link.

I have this exact same issue (I've got a 53mm basket). I've alternately left divots with my WDT, avoided nutation (because that made it worse), and finally I just picked up a cafelat convex, and it effectively eliminated the problem and made my pours more even. I've read that a flat tamper increases extraction yield, but since I can eliminate WDT, it's working great for me.

lawn_wrangler wrote: That technique looked like too much work for me. I've found it quicker to dose into an OE Ipanema cylinder and WDT with a cocktail whisk leaving a slight depression of grounds in the center. Then a couple light settling knocks on the counter, remove the dosing cylinder and tamp with flat tamper.

I've been doing the exact same thing with good results. I was just wondering if a convex tamper base would improve anything.