My long and rambling path to preinfusion/pressure profiling - Page 43

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#421: Post by pcrussell50 »

Jake has been extremely helpful to those of us needle valving our BDB's so he and I were PM'ing about this and that related to valves and tubes and such. In some side talk, we have talked about extraction techniques and it looks like we profilers are developing a whole new vocabulary. Things like: Slayer profile, declining Slayer profile, Blooming, (or Rao bloom), rule of thirds, Etc... We need a name for the "not quite espresso, "super lungos" that Jim developed, (and that I blundered into a few months ago). Anyway, a whole new language in this profiling game.

"Hey Jake, how would you extract this [insert name or qualities of bean]?" Jake answers, "Declining Slayer."

These are not specific temperature and pressure recipes, but rough profiles and techniques, to be refined by the end user.

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#422: Post by Mesmer »

Don't you just hate the free advertising in these profiles? Mainly to Slayer and Scott Rao :D

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#423: Post by Denis »

There is nothing new in the new era machines. Just the same old to a level that suits the modern gadgets.

Slayer decreasing profile is exactly what a spring lever espresso would do 50-80 years ago. Nothing new there.

Pretty sure Rao is not the man who discovered bloom, as bloom is used in different coffee methods and people have used this method before his post. He is just spreading something, didn't discover it.

We like to associate things or methods to stuff we are familiar with, but they where there long time ago, just with a different name.

There are people doing "bloom" without knowing what bloom is in a La Pavoni machine, and this was made from the 1960. :D

Therms to speak with someone else are good, but they are not the same, since you don't have the same machine, calibrated in the exact same way, with the same grinding and the same coffee and the same water, and the same taste profile.

Look at Lelit Bianca, if you say to another guy you pull your shots with the paddle at 45 degree, this is not accurate or same flow from a machine to another. Best to try and see what is best from your perspective, dont copy others, just get inspired by them.


#424: Post by pcrussell50 »

Re ^^^

I have levers too. Two of them in fact. Both Pavonis.

What you say is true of course. But it does not negate the good work of the large talent being done in the pump world. Not only that but even expert tasters like Jim (who is also a leverhead) are still in the discovery phase here. A lot is still not known. And as it is discovered, new lingo will grow up around it.

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#425: Post by Bunkmil »

Jake when you do a blooming shot do you find any advantage of using a slow flowrate in the first part of the shot before the blooming stage ie basically filling the headspace?

In your last video it was like a 30s step at about 1.5ml/s. I am pretty sure that this isn't your max flowrate right?

Of course it makes the top of the puck being exposed to water for a longer period of time but is it a good thing to do to get an even extraction?

I will do some testing with my DE1 but I am also asking in case you have an opinion on that.

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#426: Post by Jake_G (original poster) »

Thanks for the kind words, fellas.

Regarding the lingo,

It is true there is nothing new under the sun. Levers have been being levers since forever, and any machine lacking a 3-way can bloom to your heart's content. What's different is how we are thinking about the application of these techniques and overcoming many of the shortcomings of pump driven, solenoid (or leveta) actuated brew groups. Maybe we can drop the "Rao" and everyone will still know what a blooming shot is. :wink: I don't think he cares either way.

Furthermore, Slayer deserves credit where credit is due regarding their development of flow profiling pre-brew. It's not the same as a lever. It's not the same as line pressure. It's not the same as anything else under the sun. What's special about it is that you can dial in the ramp to full brew pressure simply by matching the water debit to your puck. True, a manual lever can raise the brew pressure any way they please, but Slayer developed an innovative way to have a completely passive adjustment that mimics a very specific and gradual application of pressure to the lever. That's not nothing. Now, Lelit, and a little group of bandits have taken it to the next logical level and I couldn't be more pleased with the results.

Regarding machine differences and replication of techniques,

Yep, they're all a bit different. One of things I've taken great pride in throughout this thread is the lack of absolutes. There's no "do this or that" type of discussion occurring here. It's about the fundamentals of why certain phenomena impact the extraction in certain ways. By discussing things in these terms, we can develop a set of expectations relative to what strategies achieve certain characteristics in the final beverage. Again, there is nothing new under the sun, and adjusting taste by grind and dose still reigns supreme in many ways, but I think we now have an ability to augment the rules by throwing water debit in the mix. No longer must you dose low to grind fine. Now you can dose high, grind fine, and preinfuse slow with a pump machine. Not saying you should. But you can.
Bunkmil wrote: In your last video it was like a 30s step at about 1.5ml/s. I am pretty sure that this isn't your max flowrate right?
It is not.

I just pulled two shots this morning and took video to compare. One at 4.5ml/s at line pressure and the other at 7.5ml/s using the pump. I can hit 12ml/s but I was concerned about being able to stop the flow in time to actually bloom without dribbling all over the place...

I haven't done too much analysis of these but here they are. Interesting that the pump-soaked shot flowed faster than one soaked slower at line pressure. That was unexpected.


- Jake


#427: Post by Mesmer »

Just curious, what pressure do you have in the group head while blooming?

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#428: Post by Jake_G (original poster) » replying to Mesmer »

I truthfully don't know.

I use Assaf's volumetric data (28ml to saturate the puck) and interpolate soak time based off of water debit and ramp rate to zero.

For example:

4ml/s straight would take 7 seconds to deliver 28ml to the puck, unrestricted. Some pressure would be generated and flow would decay a bit, so maybe only 20-25 gets delivered. But it's close. What I do in practice is double the time and roll the flow back to zero over that longer time. This keeps much pressure from forming since the flow is on a steady decline and lends to more predictable blooming as long as I don't get distracted and botch my timing or valve position.

At any rate, I do all of this stuff and make minor adjustments based off of what the bloom does, and I think that there is very little pressure when blooming at lower flows. The higher flow soaks I am less sure of. I can tell you that faster soaks do seem to improve mouthfeel...


- Jake

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#429: Post by AssafL »

Sort of disappointing that mouthfeel and extraction don't increase simultaneously. Seems like slower darker pulls boast high EY but have less crema.

My guess is that the creaminess comes from emulsification which needs agitation which comes from flow. It could also be lower temps and that would affect hydrocolloids (some - like CMC - become thinner at lower temps).

The reason I say disappointing is that from a purely organoleptic perspective, it seems Crema (probably as it collapses) releases the coffee odors better.
Scraping away (slowly) at the tyranny of biases and dogma.

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#430: Post by Denis »

How did you figure it out there are 28ml needed to saturate puck? From DC latest videos with their flowmeters before the first drop you need ~40 ml of water before the first drip. Yes we are not having the same baskets, but the dose is the same.