Pre-infusion for the S1

Post by **daerider** » Sun Mar 12, 2006 7:45 pm

Has anyone played around with pre-infusion with the S1 yet. I ran a NC bypass to the brown wire of the start capacitor so that I can temporarily interupt power to the pump motor after one of the volumetric water delivery buttons have been pressed. Since my line pressure is regulated to 30psi, I get a nice gentle flow a brew water onto the coffee puck. I let the line pressure water infuse the puck for ~3-5 seconds and release the button on my dead-man switch which instantly activates the pump. So far the results have been very positive with virtually no channeling and very consistent extractions based on the visual cues of my bottomless portafilter. Right now I have the wiring snaked through the bottom of the machine to the switch which is just laying on my coffee counter; but if the results continue to be positive, I will probably make this a permanent modification and put the push button on the front panel for easy access. When the button is not depressed, everything works as it should so you only get pre-infusion when you want it. One added benefit with the way I chose to splice in the switch is that volumetric dosing is not changed and the pre-programmed amount of water is always delivered.

Comments please....

Post by **hlsheppard** » Sat Mar 25, 2006 4:41 am

Wow - sounds like a sweet idea.

Honestly, preinfusion is the one thing I miss (ever so slightly) about my old Isomac Tea.

Damn you folks with wiring skills!

Post by **HooHaw** » Sat Mar 25, 2006 10:00 pm

You could try manually cutting off a pull 1-6 seconds into a shot to simulate a pre-infusion. Press your preferred doser button to continue the shot. Haven't tried this though.

Post by **wgaggl** » Mon Mar 27, 2006 12:27 pm

I put in an Omega timer, if a brewing button is pressed, it delays the pump for a programmed time. And with the pressure regulator in place it works just like the pump delayed preinfusion on commercial machines.
I even added a valve to do pump driven (pulse the pump, then wait) preinfusion and played with it.

The problem with the S1 is the lack of a saturated group. I got sour coffee nd had to increase the temp quite a bit. Doing some measurements it got clear ro me that with preinfusion on the S1 one is just extending the transition period in the temp profile, which leads to a longer rise time. Not good. Unless someone installs active group heating as well.

Wolfgang

Post by **Barry** » Mon Mar 27, 2006 2:00 pm

Recognizing that most in this group are pretty handy, I can understand the desire to tinker, however, do people really believe that pre-infussion would impact the taste of a well orchestrated shot?

Post by **wgaggl** » Mon Mar 27, 2006 5:17 pm

Barry wrote:Recognizing that most in this group are pretty handy, I can understand the desire to tinker, however, do people really believe that pre-infussion would impact the taste of a well orchestrated shot?

I don't understand your question:

1) E.g. in my second paragraph I mentioned one major (sadly) negative impact pre-infusion on the S1 had on taste in my tests for mentioned reasons.

2) Pre-Infusion is part of the quest to "orchestrate" shots better by changing the way water is initially injected into the chamber (and thus affecting "blooming" time and trying to reduce channeling). There are various way to do that, but it all stems from the infusion abilities with manual groups and adding them to automatic groups.

3) Whatever you do to the variables of an espresso shot impacts its taste: temperature, time, flow, pressure, just to mention a few. Directly or indirectly pre-infusion influences all the just mentioned, and these are parameters we all try to modify to get the best shot. Of course we must not forget that experience, technique and an idea how a shot should taste are mandatory before starting to tinker with the given limitations of a machine.

So, I don't see the point in your question. Simple answer: Yes, I'm sure it impacts the taste of a shot, no matter how "well-orchestrated", as you are basically changing the character of your machine, to the better or not, that's what we're trying to figure out :P

Wolfgang

Post by **wgaggl** » Mon Mar 27, 2006 5:22 pm

HooHaw wrote:You could try manually cutting off a pull 1-6 seconds into a shot to simulate a pre-infusion. Press your preferred doser button to continue the shot. Haven't tried this though.

We discussed that before quite a while ago: This is not at all what pre-infusion does, as at the moment you cut off the shot, the 3-way solenoid releases the pressure from the group and also rips apart the surface of the coffee puck. When you press the button again, you'll get a second all-new infusion into a very messy coffee puck. :(
To prevent the solenoid from releasing the pressure you need to make some changes to the machine itself.

Wolfgang

Post by **Barry** » Tue Mar 28, 2006 8:47 am

wgaggl wrote:
Barry wrote:Recognizing that most in this group are pretty handy, I can understand the desire to tinker, however, do people really believe that pre-infussion would impact the taste of a well orchestrated shot?
I don't understand your question:

Actually, based on your response, you clearly understand my question, you just disagree with my assertion. I own a Tea which has pre-infusion as well as an S1. When all variables are held constant, coffee blend and volume, pressure, temp, flow rate, etc., the shots taste virtually identical from both machines. The fact that the Tea has pre-infussion seems to make little or no difference in the taste of the Espresso.

Post by **wgaggl** » Tue Mar 28, 2006 11:30 am

Barry wrote: Actually, based on your response, you clearly understand my question, you just disagree with my assertion. I own a Tea which has pre-infusion as well as an S1. When all variables are held constant, coffee blend and volume, pressure, temp, flow rate, etc., the shots taste virtually identical from both machines. The fact that the Tea has pre-infussion seems to make little or no difference in the taste of the Espresso.

1) "when all variables are held constant". That alone doesn't hold true if you do a shot with vs. without (pump-delayed) pre-infusion. You either have to accept that your shot will take more, or adujst your grind to speed up the flow to keep the time constant. You can't do with and without preinfusion while keeping all the variables constant.
2) You are comparing a HX machine with a E61-like group to a double-boiler machine with a passively heated group and telling me there's no difference when keeping all variables the same!? I'd rather say in order to get the same taste results on Tea vs. S1 you have to use a different set of variables. E.g.: The different pressure profiles demand different grind for similar timing; the different temperature profiles demand a different temperature adjustment to arrive at the same overall temperature.

Wolfgang

Post by **Barry** » Tue Mar 28, 2006 11:48 am

wgaggl wrote:
Barry wrote: Actually, based on your response, you clearly understand my question, you just disagree with my assertion. I own a Tea which has pre-infusion as well as an S1. When all variables are held constant, coffee blend and volume, pressure, temp, flow rate, etc., the shots taste virtually identical from both machines. The fact that the Tea has pre-infussion seems to make little or no difference in the taste of the Espresso.
1) "when all variables are held constant". That alone doesn't hold true if you do a shot with vs. without (pump-delayed) pre-infusion. You either have to accept that your shot will take more, or adujst your grind to speed up the flow to keep the time constant. You can't do with and without preinfusion while keeping all the variables constant.
2) You are comparing a HX machine with a E61-like group to a double-boiler machine with a passively heated group and telling me there's no difference when keeping all variables the same!? I'd rather say in order to get the same taste results on Tea vs. S1 you have to use a different set of variables. E.g.: The different pressure profiles demand different grind for similar timing; the different temperature profiles demand a different temperature adjustment to arrive at the same overall temperature.

Wolfgang

I agree with your points. It is not an apples to apples comparison. On the other hand, one machine does use pre-infussion, the other does not. In a blind test of a decent shot from both machines, using the same blend of beans, I cannot tell any difference and cannot identify which machine the shot came from. While I believe introducing pre-infussion to the S1 would improve the consistency of shot quality, I do not believe it would make a good shot taste any better.

Barry

Post by **wgaggl** » Tue Mar 28, 2006 12:14 pm

Barry wrote:...I do not believe it would make a good shot taste any better.

Barry

Basically what I noted March-27 in this message thread (second paragraph). I even think that due to the lack of a saturated/actively heated group shots are better without pump-driven/delayed preinfusion on the S1. The rise time in temperature profile is about 5 seconds without additional pre-infusion, the more it is prolonged, the longer the transisiton time.

Wolfgang

Note: I was considering to add an electrical group heater to solve that issue, then decided I might not be that much of a 'tinkerer' :)