If I say, do 18g in a narrower bottom basket and 21.5g in a full wide bottom basket(both have pf-spring-ridges), I get very different flavors with about the same grind.

cafeIKE wrote:Don't worry about tamping as long as it's level and consistent. It's the very bottom of things that make a difference. Once you've got it dialed, you can fogeddaboudit.

Thanks Ian - yes, I am seeing this the more I play with it. If bottom is good and top level, no sprites. Easy. If temp is dependable, great brew. Easy.
You raved over "Courthouse" beans in a distant post. That is on my near next to get list. Thanks.

OK, I have since been doing my Italian roast in larger, 18g doses in 18g basket, but at the same low temp (190) and ratio of 1:1. You're right, just as good and possibly a tad sweeter or overall smoother. I guess it has more to do with the ratio and temp than the dose.

ratio and temp, yes, though I notice that when I increase the dose I tend to get thicker slower pulls (because I forget to change the grind) that taste different... I spent the day monitoring the temp changes at the pipe going into the grouphead, and then the group itself to understand how rapidly it heats up. With a "Dragon" type machine I am trying to control that just by a steam-flush plus a little. I seem to wind up more with a 1:1 or 1:1.5 ratio since when it goes beyond that it either gets watery, or blonds-out, and I halt it. or I get a sour drink. It is actually very hard for me to get a 1:2 , so I tend to just take "what I get" and chalk it up to dose and grind. It COULD be frustrating but I realized today that simply noticing temperature tendancies is enough - I don't really need to control them... perhaps like that tamping thing - level matters more than tamp. I need Ian's levelers!!!

I have the same question also, still could not find a direction that leads to the answer.
There might involve a few things with different dose and basket,
1. Headspace between the puck and the shower screen, which will be affected by your dose and basket size
This affect the water required to fill up the gap and also the pressure, some suggest more headspace have a simular effect of PI
2. Flow rate
The samller the dose, the fewer coffee you will get in order to maintain the brew ratio, i.e. 20in40out shot will have a faster flow compairing with a 15in30out in the same time
3. Puck thickness
The more the dose you put, the higher in puck thickness, thicker puck can prevent channeling because somehow the channel need to go through a longer distance to reach the bottom of the basket. Also, to have the same puck resistant, lower dose need to grind finer because the puck is thiner.
I have learned from hoffmann's video, the precision baskets should have different resistant with different size, if we put the same coffee into different size basket according to the dose printed on it, they should give the same brew time.
But anyone tried about that? I found I need to grind finer for 15g than 18g basket.

Hoffmann introduce the concept of work required to extract coffee, saying the higher dose require more 'work' to extract than a lower dose, but I still cannot get it. Is that I need to put more work extracting 18g coffee by grinding finer, brewing hotter than 15g? I do not think it is.

I do not have rich expreience on making espresso, if I get anything worng, please correct me.

Sounds pretty reasonable.

Despite early marketing claims, you still have to change grind with the VST or other "sized" baskets. The grind for 18 in an 18 is different than for 15 in a 15.

On "more work" for a larger dose, that often just happens with more water, more time, faster flow, or other things. It's seldom something I consciously worry about.

(massive edit here) perhaps saying the same thing but I have found 18g may work fine in a (edit) narrow bottom, but coffee must be ground a chunk more fine if you put that same 18 g in a (edit) wide bottom basket.and will likely channel. (here I have been confusing the presence of a ridge for the pf holder spring, with the narrowness or width of the bottom, and the width of the holes of the mesh therin. Sorry. (end edit)

Are you saying that two baskets, identical other than the presence of a ridge, cause noticeably different extraction behavior?

If not, then "ridgeless" is likely not the difference to highlight.

EDIT - my bad. No.

I have been confusing ridgeless with wide bottom. Sorry.


These common baskets both have ridges for pf holder spring, but have a different bottom width so require different dosing.

kris772 wrote:Yes.
Thinking about this you will notice that the ridgeless basket has a much greater bottom area than the ridged basket, so the same amount of grounds is spread over that larger area more thinly - so distribution and tamping becomes way more important and channeling is much more likely. I did eyeball the size of the basket-screen holes and they appeared the same though i would need a calibrated measuring microscope to tell. This was what I experienced. And because of the above, it makes perfect sense.

aprox D= 49mm to 53mm - aprox 153mmsq vs aprox 166mmsq area=pie*D
So assuming same vol of grounds, thickness of puck will be less.

And mine is not a "true ridgeless" so the effect would be more pronounced on the $30 basket.



image

Things might get too complicated if we involve different type of basket here.
The VST precision basket is like the industrial standard, pretty sure most of us can share our experience on the VST and may be at the end we will be able to conclude something useful.
Those VST basket is totally worth the money for me, seems they can accept finer grind and bring out more flavour, but the downside is they require better grinder/puck prep skill.