Flow Control: An alternate prefinfusion method?

Recommendations for buyers and upgraders from the site's members.
ziptie

#1: Post by ziptie »

Wouldn't a super slow flow rate using a flow control-equipped machine serve as reasonable preinfusion/ramp-up-to-the-pull for machines without an outright prefinfusion feature?

I'm coming from a La Pavoni, so as a direct lever, it has its own on-the-fly means of preinfusion...which I like. But it's the manual transmission of espresso machines, a challenge to be consistent to put it mildly.

I'm looking to add an E61 machine. It appears that many have the ability to accept a flow control assembly. Thinking ECM Classika w/PID + flow control.

So is flow control a legit add-on to aid in prefinfusion?

Nunas
Supporter ♡

#2: Post by Nunas »

ziptie wrote:Wouldn't a super slow flow rate using a flow control-equipped machine serve as reasonable preinfusion/ramp-up-to-the-pull for machines without an outright prefinfusion feature? I'm coming from a La Pavoni, so as a direct lever, it has its own on-the-fly means of preinfusion...which I like. But it's the manual transmission of espresso machines, a challenge to be consistent to put it mildly. I'm looking to add an E61 machine. It appears that many have the ability to accept a flow control assembly. Thinking ECM Classika w/PID + flow control. So is flow control a legit add-on to aid in prefinfusion?
In a word, yes. But, you don't have to give up your manual transmission. When installing an FCD on an e61, you can go either of two ways. If you install the heavier spring that comes with the FCD kit, then you're in full manual with no e61 automatic preinfusion. To my mind, this would be as close to a lever machine as one can get on a pump machine. On the other hand, if you retain the e61's spring, you'll have a kind of semi-automatic transmission, to continue with your analogy. With this spring kept in place, the FCD at first operates like a variable preinfusion control. If you crack it open only a little, the e61 will take its time ramping up. If you open the FCD to the equivalent of the stock jet (usually about 1-1/4 to 1-1/2 turn), then the e61 will operate with the normal, faster preinfusion. At any time, you can move the control to change the jet size, and thereby control the flow/brew pressure. Once the e61 preinfusion valve throws (at about 4 bar), then the FCD control operates exactly as it would with the FCD kit spring.

I'm currently using the e61 spring. I "dial in" the FCD control on the first shot or two of a new coffee so that the preinfusion is slow, and about the time the group pressure hits 8-9 bar, coffee starts coming out. This varies by bean and grind, but is typically 1/2 to 3/4 open. I don't touch the control. As the coffee comes out, the group pressure drops on its own a couple of bars, simulating a spring lever pull (unless, of course, there's channeling, in which case one sees a sudden drop in pressure). Of course, I can move the control, watch the pressure gauge, and achieve whatever profile I want.

Recently, I've been experimenting with espresso pour-overs, where I put coarser grind in my triple basket, then control the flow with the FCD to achieve a very slow, low pressure (1 to 2 bar) extraction into a mug at about a 1 to 15-20 ratio (ratio depending on how strong I want the coffee). I find I like this better than pulling a shot and adding hot water (Americano).

If you buy an e61 machine, I highly recommend getting an FCD kit.

Auctor

#3: Post by Auctor »

Nunas wrote:As the coffee comes out, the group pressure drops on its own a couple of bars, simulating a spring lever pull (unless, of course, there's channeling, in which case one sees a sudden drop in pressure). Of course, I can move the control, watch the pressure gauge, and achieve whatever profile I want.
One of the things I've wondered with a rotary pump machine is whether you MUST reduce flow over the course of the shot in order to mimic a spring lever. Trouble with the rotary pump is that it's blasting water at the puck at a very power rate (much harder than vibe pump or by hand (manual lever) or spring). As the puck erodes, that forceful flow may cause premature puck erosion and *late* channeling (if that's a thing!). I've been hypothesizing lately that there's value in flow control at the beginning (preinfusion) and at the end (to gradually end the shot). Thoughts?

ziptie (original poster)

#4: Post by ziptie (original poster) »

Nunas wrote:In a word, yes. But, you don't have to give up your manual transmission. When installing an FCD on an e61, you can go either of two ways. If you install the heavier spring that comes with the FCD kit, then you're in full manual with no e61 automatic preinfusion. To my mind, this would be as close to a lever machine as one can get on a pump machine. On the other hand, if you retain the e61's spring, you'll have a kind of semi-automatic transmission, to continue with your analogy. With this spring kept in place, the FCD at first operates like a variable preinfusion control. If you crack it open only a little, the e61 will take its time ramping up. If you open the FCD to the equivalent of the stock jet (usually about 1-1/4 to 1-1/2 turn), then the e61 will operate with the normal, faster preinfusion. At any time, you can move the control to change the jet size, and thereby control the flow/brew pressure. Once the e61 preinfusion valve throws (at about 4 bar), then the FCD control operates exactly as it would with the FCD kit spring.

I'm currently using the e61 spring. I "dial in" the FCD control on the first shot or two of a new coffee so that the preinfusion is slow, and about the time the group pressure hits 8-9 bar, coffee starts coming out. This varies by bean and grind, but is typically 1/2 to 3/4 open. I don't touch the control. As the coffee comes out, the group pressure drops on its own a couple of bars, simulating a spring lever pull (unless, of course, there's channeling, in which case one sees a sudden drop in pressure). Of course, I can move the control, watch the pressure gauge, and achieve whatever profile I want.

Recently, I've been experimenting with espresso pour-overs, where I put coarser grind in my triple basket, then control the flow with the FCD to achieve a very slow, low pressure (1 to 2 bar) extraction into a mug at about a 1 to 15-20 ratio (ratio depending on how strong I want the coffee). I find I like this better than pulling a shot and adding hot water (Americano).

If you buy an e61 machine, I highly recommend getting an FCD kit.
Thankyou, that is very helpful. I clearly have some E61 homework to do. I did not realize that they have a spring. This seemed like one of those grey area topics that I wasn't sure where to inquire...or search for.

FWIW, I have no intention of parting with my LP. This would be, if anything, a nice comparison learning experience. Maybe even to help me refine my LP pulls too. :)

Nunas
Supporter ♡

#5: Post by Nunas »

Me too. I also have a spring lever and a manual lever machine. As for e61 homework, check this out E61 Group Espresso Machine: Detailed Interior Schematics As you can see, there are three springs. FCD kits come with a replacement for the middle one, which is the spring that controls the e61 inbuilt preinfusion. That spring gives a slowish ramp-up to ~ 4 bar.

ziptie (original poster)

#6: Post by ziptie (original poster) » replying to Nunas »

Outstanding! Thanks again for your input.