Human Power - Driven by Science


(Paul Clearfire) #1

Greetings all. Not so much a question, just wanting to let you all know what I’m up too and get any advice or questions you may have. My apologies if this post is in the wrong place.

I live in a very small community (pop. 90 or so) in the Oregon Cascades called Breitenbush Hot Springs. Given that we live far away from… well, everything, we generate our own power from the river, and thus heating elements and large electrical loads are frowned upon. I moved here 14 years ago and have since been pursuing a growing obsession with reliably producing human-powered espresso shots and lattés that will take me to my happy place. About a year ago, I discovered BH, and that has seriously changed my game. Many hours of reading, research and practice, as well as several hundred USD later, I feel I may soon be ready to start making some worthy contributions to this site. Presently, I’m still working on consistency, but here’s what I’ve got so far:

Please see the attached pics. This is my kit:
-Rossa HC-P hand extractor w/4 naked heads
-IMS 55mm 20g competition baskets (I’d have gotten VST, but they don’t make a 55mm)
-Rosco hand grinder
-Acaia Lunar Barista Scale
-Espro calibrated tamper (flat)
-Anchor hocking graduated shot measure
-Stainless graduated steamer pitcher w/rattleware thermometer
-Vintage Vesubio stovetop steamer (best I’ve ever found)
-Stainless steel kettle w/built-in thermometer (a frankenkettle - modded myself)
-Vita vac containers for freezing/storage

A note on the vita vac containers: I just acquired these after reading a post from Matt wherein he extolled the virtues of grinding frozen beans, and suggested one might pre-weigh and freeze one’s dose -if only one could find appropriate single-dose vacuum container. Behold! These tiny vacuum-sealed containers are a perfect fit for my 21g dose - and could comfortably fit up to 23g. Their vacuum seal is not perfect, but I expect it will be good enough for a week’s worth of single doses. I also found some Avery write on/wipe off labels so I can document the roast date. Currently brewing Nossa Familia Full Cycle.

With this kit I can monitor and control grind, tamp pressure, extraction temperature, pressure, and time, dose, yield (gravimetric or volumetric), bean temp, grinder temp, milk temp, and milk volume, and all done by hand - no electricity needed (except for my freezer, of course). Heat for water comes from propane.

My current targets;

Dose: 21g
Yield: 42g (which about equals a 50ml shot)
Time: 36-38s

I typically extract at 90ºc and 9 Bar pressure - though I have been playing around with pressure profiles. Current favorite is the “Short Stop” profile - see Ross’s posts at the portapresso site for more info.

I buy my beans once per week when I go into town (about 120 miles away). Up until now I’ve needed to adjust grind size a good bit from the start of the week till the end, and my current theory is I’m dealing with oxidization. I’m hoping the new Vita Vac containers and freezing ASAP will reduce that variability. Currently grind size is between .55mm-.70mm (according to the registration marks on the Rosco).

We also draw our water from the river and treat it ourselves - as minimally as the state will allow - and keep PH reliably close to 7. We are the first user (nothing but wildlife upriver from us all the way to the source about 12 miles away). This is some of the purest water in the world.

I can’t really justify the cost of a refractometer, but oooooohhh I’m so tempted ;-). Really.

Although I’ve been building this kit for the last year or so, I still consider myself a novice - or at least I still haven’t yet mastered consistency. Once I feel I’ve got a firm handle on all the variables, I hope to start formalizing my tastings, tracking my results and sharing what I learn. I’d like to give a shout out to Ross over at Portapresso. These hand-powered machines are both beautiful and technically superb.

Please let me know if you have any questions, comments or advice.

Oh, and if you happen to be coming to Breitenbush - or even if you’re in the area - feel free to ping me and stop by to talk shop and share a shot or two.

Cheers!

Paul Clearfire
Breitenbush Hot Springs Retreat and Conference Center
Detroit, OR USA


(Paul Clearfire) #2

Update: freezing my beans is definitely having a major positive impact. Direct comparison between shots using frozen or just plain refrigerated beans with all other variables remaining the same shows the frozen beans producing shots that have easily 3x the crema and a sweeter, richer taste profile. I also observe that the puck appears to have more fines and appears more evenly distributed out of the grinder. I do not yet have enough data over time to state whether or not this solution will also stabilize production over the week. I’ll update this post when I know more.

-clearfire


(j l) #3

Interesting, hopefully will see this in action. I have had some good shots and bad shots with the ROK, very hard to be consistent with that hand press system.

I freeze all the time, and it does help with consistency of grind meaning that I can brew with “finer” grind for higher extraction.

It seems you tapped the chamber to measure pressure? How fast does pressure build when hand cranking?


(Paul Clearfire) #4

Hey there, homecafe

This isn’t a ROK. It’s a Rossa HC-P made and sold by Ross Spencer of Portapresso in Australia http://www.portaspresso.com/page001.html. I have owned and used several ROK/Presso units over the last several years, but have utterly given up on them for several reasons. The Rossa is a far more precise and capable machine. The pressure gauge comes as a standard feature. I can highly recommend it as a definite upgrade over the ROK.

How fast the pressure builds depends on how quickly I turn the crank. Typically I go for a quick build to 1/2 bar for pre-infusion (just a few cranks needed), then after about 10 seconds holding steady at 1/2 bar I crank quickly up to 9 bar, which happens in just a few seconds.

-cldarfire


(j l) #5

Sorry, wasn’t meaning to imply you were using a ROK.

It was just my experience with it, and I have stopped as well.

I watched the youtube video for the Rossa HC-P and it seemed like it was 30 plus seconds before being visible into the cup.