Hi HB'ers.
good day to everyone.

i am looking on opinion /experience from those who have/had personally tested baskets.

i have bdb with stock double, ims and vst15.
i am looking for options to 'increase' flow rate at very find grind size.
can i expect faster flow with same dose using vst18 or vst20?
as far as i read vst basket have bigger holes as the size increase.
i dont mind extra fines in the cup.
the ims and bdb stock is a wash, ims just half grams a dose or more faster.

i can(and have) underdose vst15 to see if i can increase it as well, and it works. but i just like more options on the yield and controls.

so my question would be,
so would a decent 10g flows faster than vst15 at 10g?
would dosing 15g in 20g basket also gives me faster flow?
can i still hit 9bar pressure or will it hit and drops (still ok), or never hit it (emm.. maybe not ok)?

i am not interested in non-straight walled basket.
any input would be appreciated.

thank you very much.

Flow in the system is a function of the "resistance" of the puck/basket system and the pressure applied. Below somewhere in the 8-10 bar range, higher pressure and higher flow go hand in hand. "High-flow" baskets generally create a less resistive system. Too much flow at high posture and your pump may not be able to keep up, especially if a vibe pump.

Whether you can make the puck resistive enough for your goal will depend on at least the grinder, beans, water, and your prep skills.

What are you trying to achieve? How much are you willing to spend?

simply consider my test an extreme version of going from double wall to single wall basket.
more specifically, im more of less trying to figure out if i can have less restriction from basket relative to puck resistance. i also would like to know how fine/coarse i can tune my grinds to get same tasting shots with better dosing efficiency.

in pricing, for im just looking at changing baskets and push limits of what i can do and learn with current setup.

i still have some rooms to go finer and choke a 9 bar shot with 10g in a vst15, so i have no issues going bigger or smaller basket, as long as its less restrictive / flow faster.

Basket resistance is a very tiny proportion of the resistance of a properly prepared puck.

Puck resistance changes with depth and various basket shapes alter puck resistance more than the hole pattern or diameter.

I can tell you first hand the VST20 flows insanely fast, even faster than 18, I've never liked that basket and never been able to dial it all these years. Just never liked taste from it.

Personally if you want to push, I would chuck vst in the trash lol, just do slayer mod and HQ baskets and you can take the machine way beyond what VST can do lol. I have a modded BDB as well. I pull out the VSTs once in awhile to play with, but they alway go right back in the drawer. Same with GS3 and others machines I've had and multiple grinders.

My experience is that VST15, 18 and 20 give the same flow for a given grind and dose. In other words I need to grind coarser when switching from lets say 14 grams in the VST15 to 18 grams in the VST20.
If you really want something faster flowing and money is not an issue, then I have understood that the Weber Unifilter is even faster flowing than VST baskets.

Interesting thread. I've got a bunch of baskets of various size and quality. I put them each on my machine with no coffee and ran a water debit on each. There was no significant difference between them. I agree with Ian, the puck's the main thing controlling the flow. Of course, it's probably more complex than just puck or basket alone. That is, my baskets all have different shapes (e.g., straight sides, sloping sides, different depths...) which may affect the way the puck forms. Based on my rather non-scientific test, the one thing it isn't is the number and size of the holes in the basket.

There is a point where the basket takes over (pressurized basket with a single hole), but even a single LM basket with only a handful of holes (compared to a VST 20) will flow the same without a puck.

The thing that matters with a basket is how thick a puck of a given dose ends up being. Hole area is generally a good corollary for how tapered a basket is, and thus how thick or thin the puck is, hence the common thought that more holes = faster flow. I have yet to see a basket that yields a thicker puck than another and yet magically flows faster...

Faster flow means you can grind finer. Grind finer and you extract higher. Or so goes the logic.