cmin wrote: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.

thank you.
i figured i'm already looking at flow control with what im doing, but gonna run my bdb under warranty first. keeping my grinder n machine it seems my only remaining options to work with is basket.

Jake_G wrote: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...

good point. however if i simply pour water with a kettle thru vst, ims, and bdb basket, what comes out below is different and easily seen. i think machine also have a flow ceiling when not under restriction. im looking at how the pressure bottlenecks flow in pucks. thanks.

JohanR wrote: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.

meaning if i dose 14g in vst15, and 14g in vst20, both would flow the same?
not gonna go weber. i dont even known if it'll fit bdb, since scace doesnt.

mathof wrote:What is the advantage of a faster flow? Not long ago, people on this forum were vaunting the results of long pre-infusions followed by very long extraction times. Now, perhaps following the invention of turbo shots, very short extractions seem to be favoured.

i dont like turbos. i do drip as well, and turbos are just relatively too linear in taste to drip from my experience. doesnt wotk with milk too, it emphasize strong acids.
it is very easy to achieve, but i like complexity of 9 bar shots.

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

as i go finer, that the brew necessitates very long preinfusion, i find puck flow no longer efficient, what happens is upper half of puck gets extracted much more than lower half.

this is probably where blooming method starts i guess. allowing puck to bloom allows more smoother flow unlike continuous pressure that continuously build resistance. but i dont have method to execute this well, so i look at alternative.

whay i have tried is doing a 1:1.1 gives a lot of sweetness and floral notes, but pulling to 1:2 (lower half puck turns pale) results in boring muddled cup.

i tried separating the first and 2nd part of shot. the 2nd half of shot has both good flavor and also overextracted ones.

underdosing (a lot) had helped me produce a very tasty 1:1.7 with minimal amount of dark layer at lower puck, hence more efficient flavor extraction, and maximizing good part of the beans. but this leads to a very small yield. it also requires a meticulous puck prep to work. the resulting small yield however is both tasty as is, and easily cuts thru 5:1 ratio of milk while still having obvious character and aroma.

one hypothesis i have here other than continuous puck compression is that the basket filtration also adds bottleneck to the puck, slowing the last half of the flow... well maybe.
this would also (maybe) imply bigger basket are no longer efficient at normal 1:2, and requires shorter ratios and less yield..

i'd like to try it.
thanks for the replies.

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

Thanks. I suppose the logic is that finer grinds expose more surface area to the brew water than coarser grinds, and as the surface layer gives up its coffee solids more quickly than deeper layers, to which the water needs time to penetrate, contact time can be lessened with a fine grind. Is that it?

Basically, yes.

iyayy wrote:
as i go finer, that the brew necessitates very long preinfusion, i find puck flow no longer efficient, what happens is upper half of puck gets extracted much more than lower half.

this is probably where blooming method starts i guess. allowing puck to bloom allows more smoother flow unlike continuous pressure that continuously build resistance. but i dont have method to execute this well, so i look at alternative.

Here is the way I do it on an e61:
An Even MORE Considered Approach to E61 Flow Control (now with video)

PIXIllate wrote:Basically, yes.

Thanks for the confirmation. It's good to feel I'm on the right track. Everything I've learned about this hobby has been picked up online (combined with reflection and experimentation). Unfortunately, none of my friends share my enthusiasm (except to come round for coffee).

PIXIllate wrote:Here is the way I do it on an e61:
An Even MORE Considered Approach to E61 Flow Control (now with video)

thanks. i never had experience with e61 but i'll go through it. might learn something new.