Tonefish wrote:I think that is incorrect programming of your stated objective to replicate Dan's 4-9-6, versus a DE1 limitation (or at least I'd hope so).

You seem fixated on this point, not sure why. My goal was to present data relating to the thread topic (simple measure of preinfusion), not to replicate anything. If you read my post, it clearly states "inspired by", not "replicate". I could have used any number of other profiles, but happened to choose this one.

Tonefish wrote:My Ulka pump driven E61 machine can hit 4 bar within a second. ... Heck, I'd like to see how quickly the DE1 can get to 4 bar too. ... I think your machine can get closer, you just have to program it correctly.

From your graphs, this claim appears to be based on the Lelit gauge, not actual brew pressure. Your group gauge (presumably true brew pressure at the basket) does not hit 4 bar until 8 seconds have elapsed. This is similar to what I see on the DE1.

You have now accused me of 1) not being able to read and 2) not being able to use my machine. I will not waste any more time responding to your posts.

CarefreeBuzzBuzz wrote:I am still at a loss to understand why first drops or 5 grams matters on the same machine BECAUSE aren't there so many other variables that come into play that impact the time even with the same coffee? Can someone explain this is a non-engineer type?

This is a really tough problem, and even though Jim reminds me of some of my old hard-nosed professors giving out a problem knowing it will be a real struggle, it really isn't (or shouldn't be) engineering oriented. One analogy might be the first set of medical folks to try to come up with a simple approach to triage. At first, the number of variables would be overwhelming. It will be interesting to see if this collective can come up with that simple measure given how easy it is to get wrapped around the axle of variables.

RapidCoffee wrote:You have now accused me of 1) not being able to read and 2) not being able to use my machine. I will not waste any more time responding to your posts.

Not true John! When you said you ran 4ml/s flow instead of 4 bar pressure I asked if you might have read it wrong. Then you said your machine couldn't do it and then you said it could. I'm done with the silliness too. All because you said you were inspired by something that was 4 bar but you did 4ml/s instead, and I questioned whether that was intended. Either way, the inlet flow is a non-starter for this goal due to all of the reasons stated.

Jake_G wrote:... the nomenclature is not helpful, given what's going on. If "infusion" means stuff is coming out of the basket, then "preinfusion" is anything before that happens.

This has really got me thinking. Recalling from your awesome thread that on any of the longer preinfusions, and especially with a ristretto pull, the coffee going into the cup is largely from the water that was introduced to the coffee during what we call "preinfusion." With that being the case, the preinfusion is really the "infusion" and the rest is the extraction. It's almost as though preinfusion is really pre-extraction infusion.

To put it another way, the water entering the coffee during what we call preinfusion is the majority of water that ends up in the cup. Again, this is for longer preinfusions and not long shots. As you notionally stated in your thread IIRC, it seems the water introduced during the extraction really just pushes the infusion (done during "preinfusion") out into the cup (along with additional simultaneous infusion although maybe not the majority), and most of that post preinfusion water remains in the basket after the pull.

The problem is easy. It isn't when PI is over. It is about how do you describe a recipe that is - say - 90% accurate and wholly repeatable.

We don't know when PI is over unless that puck drops. And by then PI was over some deltaT seconds prior.

In the past PI was 4-10 seconds, first drops immediately become pours so the PI demarcation point was clear.

With extra long PI, one may pull back on the lever/paddle/pump motor and keep the puck saturated for additional time. First drops, last drops, etc are not clearly demarcated and easily become ambiguous. 5 gram in cup is clear and unambiguous.

It isn't about right or wrong. We won't know what right is anyway. It is about repeatability and unambigousness.

AssafL wrote:The problem is easy. It isn't when PI is over. It is about how do you describe a recipe that is - say - 90% accurate and wholly repeatable.

I'n my view the "problem" is the full effort including the solution, and a qualifier I would expect is that it would be useful. Going back to my triage analogy, it is easy to say we want to treat the patients in the order of most need, but a lot harder to come up with the solution becasue there are so many different ways a patient can be in need .... thus the problem. The problem here too, is that there is not a single recipe, there are many, many recipes. Anything that results in good coffee should be a candidate. Machines vary, coffee varies, and approaches vary, but too simple a solution can easily be meaningless. The challenge was presented here with Jim's original post:

another_jim wrote:My suggestion, to get the ball rolling, is time to 5 grams of shot weight. That would include the time the long, slow drip preinfusions take. But I'm sure the members can come up with something better than that.

I think he expected us to go further than just agreeing with him unless there is no way to come to a more meaningful answer.

Assaf, How would you find this time to 5g useful?

another_jim wrote:That has my vote too. I was once taught that science begins when you stop worrying about what something is, and start worrying about how to measure it. On the other hand, in my social sciences, we are inundated by BS measurements because nobody can think productively about whether there are fundamental dimensions, and what they might be.

Did you just vote for your own idea? Same question for you though, Jim. How would something that simple be useful? A fair comparison to consider it's usefulness might be to say that a roasting of coffee should be 10 minutes. That is too simple to be meaningful, isn't it?

I was hoping an answer could be reached somewhere between a meaningless too simple number and the gory detail of every approach for every machine. I thought you were too. Discussions where many ideas from many different perspectives are floated usually are the way to solutions that can leverage multiple inputs to a better solution.

I wasn't ready to give up, so I'd say futile would be a more appropriate label for the thinking of those of you who are. So one last question regarding "wholly repeatable": What do you think the chances are of repeatability between users with some level of control over their machines, with just that one duration number?

I would think that at least some notion of pressure and maybe flow would increase the usefulness considerably even though it is binning. Something like:
- low pressure, high flow (like a lever, slayer)
- low pressure, low flow (trickle, blooming)
- line pressure (3-4 bar like many machines, and an E61 that could be bumped to hold pressure beyond the 8-10 second chamber filling)
You could list a few of the more common options and then have a custom (maybe with notes) to catch all of the others. That along with time to n-grams could be a more meaningful but still simple input.

Since someone above mentioned also noting the time at which drips change to flow, I'm starting to record both. It may be that the 5g time is useful as a reference point rather than "defined state."

For example, the drip/flow transition time relative to 5g out could be informative. Yesterday's shot of 20g of Malabar Gold was 75 seconds for 28g out. 5g out at 40 seconds, flow transition at ~44 seconds. (if flow transition occurred at 20 seconds, that would be a very different result in the cup).

Today the 5g mark was 36 seconds, flow ~39 seconds.

In both cases I observed that the transition from drips to flow was starting almost immediately after the 5g point, and I elected to arbitrarily 'call' flow when it was fully established. It would be interesting if the 5g mark was very close to the flow mark for a lot of us across a lot of machines and approaches. We might need to name it the Schulman Transition or something like that. (Event Horizon is already taken, sadly ).

Note that I am actually not doing a low pressure preinfusion at all: I grind fine and do what I will call a "high-pressure low-flow preinfusion" which yields 30-40 seconds of long slow dripping syrupy emulsion goodness (to my taste). I've found that low pressure preinfusion delivers significantly less viscous deliciousness.