Personally I see almost zero downside to the stock e61 spring and little to no upside to the stiffer one. I guess if you wanted to deliver the fastest, most powerful amount of water in the shortest time then it would be better with the stiffer spring. And I do appreciate the benefit of a fast fill a-la levers but given how manual and sensitive the timing and feel of profiling a shot as I've demonstrated is I think it's a big benefit to have a slightly slower ramp.

I guess at some point I might get bored and finally install the other one but that also makes it much harder for the wife to use once I've gone to work.

Chris: I have to thank you again for posting your video and commentary. It's been enormously helpful and has resulted in my ability to brew much better espresso.

I bought my first E61 machine (Puristika with flow control) 4 months ago. I swapped out the stiff spring for the original spring per your and others recommendations. The slower ramp up in pressure was helpful as I learned how to use the E61 functionality and controls.

I didn't start using flow control until recently and struggled with technique despite the wonderful resources found in the user forums here. Since your machine and mine are both ECMs, using the clearly defined steps was made much easier to follow.

As a new E61-with-flow-control user, I was nearly cross eyed trying to watch pressure, timer and adjust the control valve lever. It was best for me to parse out the sequence initially by keeping a close eye on the group head manometer and moving the lever at the pressure "cues" to reach the targeted shot by weight. After getting better acquainted with pressure sequencing I added timing. No surprise when I found that both pressure and timing values aligned nearly exactly (I think the variance, when there is one, is when I adjust the OPV from 9 to 8 bars or 8 to 9, just to see how the shot is affected).

The overall result has been delicious espresso in the cup using medium-light roasts (Dogma from Paper Plane, Montclair NJ) that my spouse and I like rather than just tolerate (we've been dark roast, traditional Italian comfort espresso drinkers for over 30 years). I think your posts and video have shown us that a good machine with technique and practice can go a long ways.

Thanks again. Well done.

romlee wrote:Chris: I have to thank you again for posting your video and commentary. It's been enormously helpful and has resulted in my ability to brew much better espresso.

Thanks again. Well done.

You're very welcome and I'm glad this helped someone. To be honest I didn't use the flow control for the first year I had it other than some fooling around.

It wasn't until I started getting a better handle on extraction theory and looking into some of the advancements being made in regards to pre-infusion, flow rate, puck saturation, peak pressure and fill speed that were coming out of the Decent users dataset and traditional levers that I began to formulate a more systematic plan. And even then it took quite a bit of thinking and experimentation with different profiles/knob routines to really get to place that I consider a wholesale improvement for all roast levels.

As I've said none of the ideas behind what I've done are new or mine. What I did was figure out a way to transfer the theory into e61 flow control steps. I've been talking about it for a while but I think the only way to really communicate this kind of thing is with a video.

It's gratifying that this will save someone else the trouble or allow them to use an ignored flow control kit they own out of confusion or frustration.

As an additional note, recently in another thread Dick (who only makes singles) pointed out a parameter/distinction that should have been stated by me to begin with:

Peppersass wrote: Another data point is that I tried Chris's method without the soak (I need to do some programming to implement that), and didn't like the resulting shot at all. It seemed over-extracted, so a soak probably would have made it worse. Perhaps the reason is that Chris designed his method for doubles, not singles.

If someone is using this method and runs their shots at 2:1 or beyond (which always taste thin and watery to me) you may want to significantly reduce (or eliminate altogether) the zero flow bloom stage. This would seem to also apply to singles, which is a rabbit hole I have yet to go down.

Pretty much all of my shots are 18g in an 18g VST basket and also (quite importantly) I keep my ratios pretty tight, always falling short of a 2:1. Most commonly I'm aiming for between 32.5-33.3g out which works out to ~1.8:1 ratio.

I have a strong personal preference for intense, concentrated but well extracted shots which is one of the things I like most about my Monolith grinder; it naturally produces high EY% so even when stopping short of a 2:1 ratio I can comfortably get into the 21-23% range. I'm told by people with a Monolith MAX this can be pushed even further with shorter, more intense shots in the 1:1.5 or even 1:1 range that still manage to reach that extraction yield range and beyond. Do I need ANOTHER grinder? Perhaps....

People with grinders that don't produce as even a particle size and as high an extraction yield may be able to make up for some of those shortcoming of the grinder with the extended bloom. On the other hand, a grinder that produces a lot of fines that are then left to soak for an extended period may net you bitter flavors depending on the coffee.

I'd like to encourage people to taste, make notes, reiterate. With patience and a structure to work within better tasting shots are possible when compared to flipping the lever and watching the shot pour.

Great work and insights here, thank you very much for sharing.

now i dont have e61 but using bdb, and mostly do lattes.
by chance several month back i choked my grind settings, but to my suprise this brings out a lot of floral aroma, coffee flavor went from nice to outstanding flowery sweet in milk.

i have since been doing manual preinfusion time (bdb stays at pi setting with fixed 56% pi pump output, adjustable) and fine tuning grind.

since i cant stop flow in middle, i do a low power pi until it builds to 4 bar and release to 8.6. grind was adjusted so that the puck resistance is just enough to hopefully stay at 8.6bar for 1~2s before dropping naturally due to puck erosion. (to somewhat emulate lever pressure).
i noticed you do a 7.5ml start and drop to 4.5ml. coincidentally i also found 56% pi to work well on bdb. and thats also close to 4.5ml as well.
i guess i ended up on similar track. i havnt tried dark yet, but this seems to work well from med to very light, so i probably just need to extract less from dark roast to work. perhaps stock e61 can also do this?

unfortunately i have to cut my shots shorter, mostly getting 1:1~1.2 yield. the remaining actually have a mix of well and overextraction, and will reduce/muddy the taste from the early 1:1. i think this relates to slow group head fills and top puck extracting more than bottom. the lower side of puck will always be darker than top. i underdose to reduce puck thickness so that i waste less bean, so end up with mostly 10g on vst15. this also seems similar to suggestion to reduce/eliminate bloom + single dosing (but without the ending flow control). there is definitely some waste of good flavor, but i have no idea how to proceed without modding.

while the very small yield is still quite intense and easily cuts 1:6~8 ratio milk, a lovely desert.

i think i hit a limit on 3 points without the fcv
1. immediate water deposit. bdb takes more than 12s to reach 2 bar at pi flow. i highly suspect ths overextract top of pucks.
2. blooming.
3. reduce flow at end shot to extract more of the last bits of flavor, allowing me to extend maybe up to 1.3~1.5 ratio.

any suggestion on a single boiler e61 thats fc moddable with pressure gauge at grouphead so that i have boiler pressure flow into the group (fast fill) and flow control?
thanks.

The ECM Classika can be purchased with the FC kit installed but any e61 can be retrofitted with the valve and gauge to the best of my knowledge.

Thanks for this very helpful thread. I've had an Alex duetto for 9 months now and am still not quite up to using flow control even though I have it installed - but this thread helps and I'll probably try my hand in the next few months.

Interestingly one of my mysteries was why the Izzo FCD did not come with a stiffer spring - and whether keeping the stock spring was defeating the FCD somehow. I thought it through and got to the conclusion that the built in pre infusion chamber is doing something sensible and there will be a very limited benefit to giving you enough freedom for full control with a stiffer spring. Your comments confirm this view - thanks.

I struggle to see an upside to the stiffer spring as one of the main upsides of having flow control is to control and extend pre-infusion. Good luck with the technique. After awhile you can do it from muscle memory but understanding exactly what you're doing and why is helpful in the beginning.

iyayy wrote:i cant stop flow in middle

The dimmer mod can be installed in the BDB:

iyayy wrote:before dropping naturally due to puck erosion. (to somewhat emulate lever pressure).

That's where you need to apply the "lever profile" - to prevent that situation! When the pressure is "dropping naturally", coffee is less and less extracted and more and more simply diluted with water, resulting in an unsaturated, weak taste. You need to be constantly decreasing the flow rate so the coffee jet never becomes blond.

Ursego wrote:That's where you need to apply the "lever profile" - to prevent that situation! When the pressure is "dropping naturally", coffee is less and less extracted and more and more simply diluted with water, resulting in an unsaturated, weak taste. You need to be constantly decreasing the flow rate so the coffee jet never becomes blond.

thats what i thought too, it should allow time to extract flavor and not just wash pass it.

i still have few months warranty to go on my bdb, keeping it as is now just in case, though i hadnt run any issues so far with my treated water. will do the mods later. thanks for the link.