Posted Mon Apr 30, 2012, 2:04pm Subject: Re: Musings On Coffee Extraction, and measuring it:
Well, it's 9ish months since I last commented on this thread.
Calculating 'extraction' depends on some assumptions, and much of Earnest E. Lockhart's work back in the 50s and 60s was done with drip brewing - a method with a "sweet spot" for grind and extraction, and some variation but a major assumption for "absorption".
In a SCAE 2007 presentation, they use an example - fairly rare - for how the "standard" measurement of extraction works.
120g of coffee 2000ml (g) of brew water.
Call it 6% brew ratio.
Assumption that every g of coffee "absorbs" 2g of water - and then they go on with their 20% extraction example.
2120g total, 1760g of coffee produced, 240g of liquid "absorbed" and the wet puck ~360g.
120g * 20% extraction = 24g of TDS,
1760g of coffee with 24g of TDS is 24/1760 or 1.36% strength.
If you know the coffee you started with, the coffee produced, and the TDS % strength of the coffee produced, extraction is:
% extraction = (TDS% * Coffee Produced) / Dry Initial Coffee. In the above example, you would have measured the strength of the brew at 1.36%,
1760g X .0136 / 120 = .20 or 20% (19.94% technically).
Per the example (assume no loss): Brew Mass consists of 2120g total (2000g brew water + 1760g coffee)
and after filtering (assume everything that is not produced coffee is considered "wet puck")
1760g coffee at 1.36% strength (consisting of 24g TDS dissolved in 1736g of water)
and a wet grounds mass of 360g, consisting of: 96g of coffee (made up of undissolved coffee and undissolvable coffee solids) and 264g of "water".
If you dehydrate the coffee and the grounds, you'll end up with: 24g of dehydrated coffee from the beverage, and 96g of dry spent coffee grounds.
The 1g to 2g absorption assumption is relevant to drip methods. Maybe more maybe less. Different for espresso.
So, the traditional definition of "extraction" is how much TDS in the produced coffee, divided by the starting amount of coffee. The way absorption is calculated would be:
(WET PUCK MASS / Dry starting coffee mass)-1 = absorption ratio. This actually predicts the wet coffee mass, or end coffee produced, and is pretty reliable for drip methods.
In the example, (360 / 120) = 3, minus 1 is 2g/g of coffee.
This works, mostly, to predict the amount of coffee produced for a specific brew ratio:
1000g water, 60g of coffee, the produced coffee is (1000 - (2*60)) = 880g of coffee produced.
At a 10% brew ratio: 1000g water, 100g of coffee, the produced coffee is (1000 - (2 *100)) = 800g of coffee produced.
Next post - What do fines do to the calculation?
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Mon Apr 30, 2012, 2:40pm Subject: Re: Musings On Coffee Extraction, and measuring it:
Fines and extraction:
The example is all well and good, but the truth of the matter is that fines can change this considerably. The way it does is by how it changes what you do to determine the TDS%.
If you use a drip filter, the end result is pretty darn close between the two most reliable methods of measuring: dehydration and refractometer.
If you take a sample of coffee (say 100g) and dehydrate it, the solids left behind are the solids attributed to the coffee. If you have a 100g X .001g scale, in the above example you would dehydrate 100g and end up with 1.364g of leftover solids.
VSTapps, the leading coffee refractometer manufacturer, has done extensive analysis and validation with dehydration ovens. Their reported index of refraction method is well-correlated to special dehydration ovens.
The key here is the dehydrated sample must be filtered.
If I take a check of a press pot (aka French press), I have to pre-filter the resulting coffee to retrieve as much as a couple of grams of wet, mud-consistency fines. Then, I try and drip filter it one more time and can gain another tenth of dried fines embedded in the drip filter.
The aeropress is better than a press pot, but not as clear as drip. I'm still identifying the amount of fines that make it through - but this obviously increases the dehydrated mass, and can increase the yield.
The fines can also change the strength over time - suspended fines will increase the concentration of solids so a refraction measurement will be a few points higher the next day.
So, dehydration must be done carefully, with the samples well filtered to remove suspended solids - VST recommends using an ultra fine filter. I've had good luck with centrifuging.
Suspended solids can mess with a refractometer measurement as well - with the particles reflecting the measurement beam and causing some measurement variation.
So, taking into account that you've taken care of the fines and suspended undissolved solids - there's two decent ways of calculating the resulting TDS%. Of course, the convenience of a refractometer (and the small sample required) makes a good case for field TDS measurement.
Next up, musings on exactly what extraction is (Absorption)
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Mon Apr 30, 2012, 7:16pm Subject: Re: Musings On Coffee Extraction, and measuring it:
From the years I spent at Kodak what sticks in my head is that when we made the film emulsion just a bit 'off' we would not scrap it (expensive to do so) but keep it until we had a batch that was 'off' in the other direction and then blend them to get the right end point.
That end point was confirmed by testing.
And, as I have said before, I admire your scientific method but I don't see much discussion of 'end point'. That 'end-point' would be determined by tasting (which is a super-set of testing).
To belabour the point, if I set up identical conditions in my Aeropress, then my Bialetti Moka Pot and in my Krups Moka Brew they would no doubt have a totally different character. That is why the professional coffee cuppers have a standard protocol (modus operandi) which does not resemble the way any of us brew coffee as a beverage.
With great respect for the study work you have undertaken, could you tell us how it relates to arriving at the optimum brew conditions for coffee-the-beverage?
Posted Tue May 1, 2012, 5:11am Subject: Re: Musings On Coffee Extraction, and measuring it:
JKalpin Said:
From the years I spent at Kodak what sticks in my head is that when we made the film emulsion just a bit 'off' we would not scrap it (expensive to do so) but keep it until we had a batch that was 'off' in the other direction and then blend them to get the right end point.
That end point was confirmed by testing.
And, as I have said before, I admire your scientific method but I don't see much discussion of 'end point'. That 'end-point' would be determined by tasting (which is a super-set of testing).
To belabour the point, if I set up identical conditions in my Aeropress, then my Bialetti Moka Pot and in my Krups Moka Brew they would no doubt have a totally different character. That is why the professional coffee cuppers have a standard protocol (modus operandi) which does not resemble the way any of us brew coffee as a beverage.
With great respect for the study work you have undertaken, could you tell us how it relates to arriving at the optimum brew conditions for coffee-the-beverage?
"I used my mojotogo and determined I'm underextracting"
"the optimum extraction is 20%, 18%-22%"
"i'm under extracting, and it tastes..."
"I'm over extracting, and it tastes..."
Extraction is part of our vocabulary. I'm shocked that such an "important" parameter is so poorly understood or vaguely defined. This single misunderstood parameter is blamed (or praised) for variation in flavor probably more than any other. When something is not understood, it's blamed on "extraction". Soft water interferes with "extraction". Water temperature changes the "extraction". This or that brew method changes the "extraction".
BUT, the concept of extraction is basically unchanged since the 50s studies by Lockhart.
I liken it to my profession - vehicle dynamics. We have one response parameter we can measure, everyone feels it - it's called "steering sensitivity" and it's a measure of the response of the vehicle to steering wheel angle displacement. Put in 10° steering wheel angle at 100kph, and you get a lateral acceleration. It's one parameter of a host that tell you the "flavor" of the total vehicle dynamics of a particular vehicle.
That's like the %TDS or strength of the consumed beverage. We can all sense the strength of a particular coffee.
BUT, understanding what causes the steering sensitivity of a particular vehicle is dependent on several other factors - the wheelbase, the steering ratio, and a parameter that people don't feel DIRECTLY - called understeer gradient. This particular parameter is so important that it is one of the things that is nailed down very early in the development of a vehicle. In a way, this is analogous to "extraction".
Any yayhoo with some instrumentation can measure steering sensitivity (all you need is lateral acceleration and steering wheel angle), it takes a deeper understanding to measure and comprehend "understeer gradient" (that takes much more information).
Furthermore, coffee "extraction" is part of the end product - but this parameter is so central to our understanding of brewing coffee that most things must revolve around it - it's a central part but not the ONLY thing.
Like understeer gradient - this doesn't by itself define a vehicle, but it's probably one of the first building blocks that allows understanding what tires will do to the vehicle performance, the effects of changes to vehicle mass and distribution, platform variants, trailering, response time, frequency domain response...
Without a clear definition of the underlying concept of "extraction" - one that fits ALL brewing or coffee preparation methods - we only understand "part" of the picture.
I'm suggesting a potential revamping of the concept of "extraction" that includes other brewing methods. Ever purposefully overextract something (like grinding really fine but keeping the same other brewing parameters) but it turns out surprisingly good? Did you really change the extraction, or did the changes you made actually change they way it was extracted? If so, in what way?
How do wash through methods of brewing compare to immersion/infusion methods? Drip and pourover is a wash-through method. Aeropress and press pot, vac pot, these are immersion or infusion.
The "end point" is when I have a clearer extraction model that tells me information and allows me to predict some of the things I see while making coffee.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Tue May 1, 2012, 7:00am Subject: Re: Musings On Coffee Extraction, and measuring it:
On the concept of "absorption":
The "absorption" ratio is a predictive parameter - based on the beginning amount of coffee, the "absorption" is stated as "x grams of water are absorbed for every gram of coffee used".
This basically predicts the mass of the wet used coffee, and by subtraction also predicts the amount of coffee produced. Most studies standardize this as a ratio of 2:1, so like our example above:
120g coffee predicts the wet spent grounds will weigh 120 + (2*120) = 360g.
Brew water is 2000g, coffee is 120g, 2120g - 360 = 1760g of coffee produced at ideal extraction of 20%.
A simple model of this process looks a lot like this:
120g Dry Coffee 2000g Brew Water 6% Brew Ratio 2120g Brew Mass 1760g Coffee Produced 360g Wet spent grounds 1.36% Produced coffee strength 24g TDS in the coffee produced 20% Traditional Extraction
Based on my own drip machine (the BCM-4C), this is pretty darn close (for the masses, scaled down to 700g water : 42g coffee. The wet spent grounds are right around 120-130g, usually has about 10g missing between evaporation and spills, and the remaining as coffee (around 600g) at a fairly strong strength, using EoC 100% Colombia and a med-fine grind.
In fact, if we know the starting coffee, and we weigh the resulting products (the spent grounds and the produced coffee) we know as much as we need to know, and we can play with some predictions:
From the example:
120g starting coffee 360g wet spent grounds 1760g of produced coffee 1.364% strength.
From there, we know the end effective brew mass, the approximate brew ratio, and the amount of unextracted coffee mass and water in the spent grounds:
1760g X 1.364% = 24g coffee TDS
The spent grounds then consists of: 120-24 = 96g of undissolved coffee, meaning 264g of water left in the spent grounds.
Extraction is 24/120 = 20%
But, what happens if the spent grounds changes - i.e. the absorption is different?
Say the brew mass is now 420g, and produced coffee is 1700g at same strength? Absorption is 2.5g:g of coffee.
1700g X 1.364% = 23.19g 120-23.19 = 96.81g of undissolved/unrecovered coffee, and 323.19g of water left in the spent grounds. The new calculated "extraction" is now 23.19/120 = 19.3%
What if you took the spent grounds, and squeezed them to get much of the liquid out, and now they weigh 300g? Absorption is 1.5g:g of coffee. Produced coffee is 1820g at same strength: 1820g X 1.364% = 24.82g of TDS. 120-24.82 = 95.18g of undissolved/unrecovered coffee, and 204.82g of water left in the spent grounds.
Then, the calculated "extraction" is now 24.82g/120 = 20.7% extraction.
The question is: why does this matter?
It matters because the absorption as calculated by the normal method when applied to other brew methods varies. Of the last two dozen aeropress brews, the mass of the wet coffee puck divided by the original coffee amount -1 is on average 1.4g:1g, and ranges from 1.2 to 1.6.
A couple of cold brews are approaching 2:1 (using the Aeropress to separate grounds). Experiments with normal "'verted" aeropress (very short contact time of ~15seconds) has absorption ratio more closer to 0.9:1
If you're only trying to tell the difference between 18% and 22%, or 17% vs 19% - it probably doesn't matter, just use the traditional "coffee produced multiplied by strength divided by original coffee mass" method. But don't use a decimal place - your answer is in whole percentage.
You can set up any number of permutations using the 2:1 assumption - if you know the wet coffee and produced coffee, or if you know the brew ratio and end strength...
Bottom line is that some absorption in the coffee makes water unavailable as a solvent. This is in the cellulose and lignin of the coffee, and you can't get it out save for evaporation. Some of the rest of the mass in the used coffee is actual coffee at the strength when the grounds and beverage are separated.
Knowing how much of the coffee has actually been dissolved relies on an assumption of absorption - so that's why the definition of "extraction" is how much dissolved solids make it to the cup divided by the original coffee mass. It's easy, and tho it has a significant amount of uncertainty, it works for estimating.
Absorption plays a role in the error calculation, and this error gets worse with higher brew ratios.
For a brew ratio of 6%, given a strength of 1.364% at 2:1 absorption = 20.0% Extraction at 2.5:1 = 19.3% extraction at 1.5:1 = 20.7% extraction. at 1.0:1 = 21.4% extraction.
BUT, double the brew ratio to 12% at 3.158% strength: at 2:1 absorption = 20.0% Extraction at 2.5:1 = 18.4% extraction at 1.5:1 = 21.6% extraction. at 1.0:1 = 23.16% extraction.
(that would be a model where you use the coffee amount, the brew ratio, strength, and absorption - with those parameters you can calculate the mass of the wet spent grounds, produced coffee, and extraction as a TDS mass divided by the original coffee).
The less absorption (i.e. the more you squeeze the puck) the higher the "technical" or "traditional" extraction but does this REALLY change the extraction?
Methinks no. I've now checked multiple aeropress brews where I have the first half produced strength, the last half strength, and the strength of the "squeezings". They're the same well within measurement variation - the squeezings are no stronger nor weaker than the bulk of the coffee produced during any given press. Moreover, they all TASTE the same.
Extraction may not be exactly what we all think it is. What's the absorption for a French Press? If you look at the coffee left over in the bottom of the press - the grounds are AMAZINGLY wet - if you took that at face value it's an absurdly high absorption. If you take the spent grounds and THEN drip them and press them - you wouldn't drink that stuff. The assumptions used for drip coffee no longer really apply.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Tue May 1, 2012, 2:10pm Subject: Re: Musings On Coffee Extraction, and measuring it:
Netphilosopher Said:
I liken it to my profession - vehicle dynamics. We have one response parameter we can measure, everyone feels it - it's called "steering sensitivity" and it's a measure of the response of the vehicle to steering wheel angle displacement. Put in 10° steering wheel angle at 100kph, and you get a lateral acceleration. It's one parameter of a host that tell you the "flavor" of the total vehicle dynamics of a particular vehicle.
In 1941, when I was 8 years old, we were visited regularly by the guy from the creamery to whom we sold our milk. He would take a sample and in our kitchen would set up his little centrifuge and determine the butterfat content. That influenced the income from our dairy herd, so it was important. But we had no control. (BTW, the tests were usually 8.2 +/-1%. The milk I grew up on was close to table cream which is 10% ...!!)
Now, 'steering sensitivity' is a variable that is expensive to instrument and expensive to log in real time and expensive to implement in production vehicles, but with that control comes an improvement in road-feel and stability and safety and you can FEEL it every time you turn a corner.
When I make a cup of coffee in my Aeropress, I dump a heaping scoop of beans into the grinder, grind it, brew it at 190F for 1.5 min, do a 30 second cleanup and sit down to enjoy my brew. I wonder how 'absorption ratio' will fit into that, some day in the future.
Posted Wed May 2, 2012, 4:50am Subject: Re: Musings On Coffee Extraction, and measuring it:
JKalpin Said:
In 1941, when I was 8 years old, we were visited regularly by the guy from the creamery to whom we sold our milk. He would take a sample and in our kitchen would set up his little centrifuge and determine the butterfat content. That influenced the income from our dairy herd, so it was important. But we had no control. (BTW, the tests were usually 8.2 +/-1%. The milk I grew up on was close to table cream which is 10% ...!!)
Now, 'steering sensitivity' is a variable that is expensive to instrument and expensive to log in real time and expensive to implement in production vehicles, but with that control comes an improvement in road-feel and stability and safety and you can FEEL it every time you turn a corner. ...
Enh - not that expensive. With about $900 worth of equipment, you can pull the steering wheel angle off of the vehicle communications bus and you can get lateral acceleration with a DL1.
With coffee, you can know the strength of your beverage with $300 or less worth of equipment, depending on how accurate you want the data to be.
JKalpin Said:
When I make a cup of coffee in my Aeropress, I dump a heaping scoop of beans into the grinder, grind it, brew it at 190F for 1.5 min, do a 30 second cleanup and sit down to enjoy my brew. I wonder how 'absorption ratio' will fit into that, some day in the future.
What if you found out all this time that you've been underextracting your coffee? Yes, it might taste good, but what if it could be better, or more than it is now?
What if you found out that Ethiopia or Guatemala, for whatever reason, requires a slightly finer grind relative to a Kenya or Colombia? Or that lighter roast coffees need a longer contact time for full extraction?
My thinking is that if I could understand the overall process (not just keep measuring the strength and using the same old 60 year old calculations) and also understand how repeatable the brew process is, maybe it would be possible to re-state or re-organize the brew charts for a new century.
We all know that same brew chart - it's the same darn thing we've seen from the SCAA and the SCAE. It was developed with a drip method, worries about "grounds depth" (completely irrelevant to immersion brewing) and percolation rates (again, irrelevant to immersion brewing). It has three parameters - brew ratio (in grams per OZ! - WTF is up with that??? the dimensions on that are... what again?), strength and extraction. It applies to one brewing method and one set of brewing parameters, and one set of assumptions.
We routinely brew double or triple strength at times, the brew chart only goes up to a strength of ~2% and assumes linearity - but that isn't my experience so far. That's part of what started me on investigating what we all mean by "extraction".
I guess part of it is I don't like things that don't make sense. Once I have coffee that has been extracted/dissolved into solution, I don't like an estimated calculation that is dependent on how much of the coffee I get out of the brew mixture - a very fine grind in a drip brewer or pourover cone is less than ideal - it can take a really long time (and a fair amount of evaporation) for the coffee to gravity drip out of the basket, and then you can still squeeze several more grams out of it.
If you're trying to overextract in a drip brewer - grind finer, this will increase contact time (reduce the percolation rate) and increase extraction. You can TASTE it in both the strength of the produced coffee and the flavor profile. Yet, because the fine grind retains more water, the calculated "extraction" can be... right about the same or only slightly higher, but not fully into the "over extracted" region.
The actual extraction hasn't changed but the calculation of it has. If I wanted to understate my extraction, I just allow less to end up "in the cup".
That's like saying a measurement of "steering sensitivity" is dependent on who does the test.
Assumption (what the absorption is) is nothing more than a placeholder for further knowledge.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Wed May 2, 2012, 1:49pm Subject: Re: Musings On Coffee Extraction, and measuring it:
I should not comment further because I DON'T disagree with what you're doing and I feel I am on the edge of being argumentative.
But I will warn you that some things are so complex they cannot be broken down by 'scientific method'. Yes, you can control wine-making and yes, you can control beer brewing and ...maybe... you can eventually control the many processes of coffee preparation. If so, it will make my 10:00am cup of coffee endlessly complicated. It will not be an 'easy' cup.
I will downshift into a story. I had a long relationship with a world-class classical music composer (half a lifetime). He eventually did use a music annotation program, but for composing he just sat at his upright piano, tried this chord and that, scribbled endlessly on his 5-line score paper and created his own kind of magic. He could not articulate why his music was magical. It had variety. It had passion and sadness and happiness. It had structure and it had 'steering sensitivity' within the plan, but he could not explain it and neither can I.
In conclusion, I think he had too many variables to get his head around and maybe he 'lumped' them. I am hoping that you will, somehow, arrive at a system of 'lumped' variables that will improve MY cup of coffee but not drive me crazy with gismometry to achieve it.
LOL - I don't see meaningful discussion as "argumentative" at all.
JKalpin Said:
But I will warn you that some things are so complex they cannot be broken down by 'scientific method'. Yes, you can control wine-making and yes, you can control beer brewing and ...maybe... you can eventually control the many processes of coffee preparation. If so, it will make my 10:00am cup of coffee endlessly complicated. It will not be an 'easy' cup.
I will downshift into a story. I had a long relationship with a world-class classical music composer (half a lifetime). He eventually did use a music annotation program, but for composing he just sat at his upright piano, tried this chord and that, scribbled endlessly on his 5-line score paper and created his own kind of magic. He could not articulate why his music was magical. It had variety. It had passion and sadness and happiness. It had structure and it had 'steering sensitivity' within the plan, but he could not explain it and neither can I. ...
Funny you should bring that example up - I was JUST going to post an example in the area of music.
Ever hear of Glaser & Westergren?
No?
How 'bout the "Music Genome Project"?
Vaguely familiar?
These guys thought that if you could categorize music attributes, capturing the essence of a musical piece - ANY piece - then you could create an entire taxonomy of music.
We know it today as Pandora. Not only does it work for music, it also works for comedy. You can potentially use it for tailoring not only what you ARE looking for, but you can potentially use it to filter out stuff you absolutely HATE.
I guess the goal is that I hope to know more about a cup of coffee than I do now. Eventually, with a few parameters, I might be able to tell you something about your coffee that you don't know now.
For example, we know that contact time and grind will change not only extraction but how the coffee is extracted. What's the sensitivity? Without a clear, sensible, testable and repeatable measurement of "extraction", we're wandering around because of parameter confounding.
I'm at a stage where my explorations show me that for a given coffee, even with my $70 Bodum Bistro grinder and an AeroPress, I can duplicate brew strength for a given brew ratio within measurement error. Not just once in a while - I can basically nail a target strength for a given coffee in as many as 8 successive brews over a period of over a week (1.95% +/- 0.02%, for example). The taste of the coffee over this time is also very stable. That's useful information - I never knew that before.
But variations in pressing alone have the extraction varying by more than a full percent. That just doesn't make sense.
So, for me, I have to figure out what is really meant by extraction - then I can understand how changing the grind differs in taste and extraction, vs. contact time. Or if there is a difference in contact time with respect to brewing methods. Or, with an immersion method is there a limit to the amount of coffee that can be dissolved? I can underextract a 6% brew ratio and a 12% brew ratio, but I seem to have trouble over extracting the higher brew ratios.
Without a stable way to determine this mythical "extraction" (especially for immersion methods), I'm just stumbling around with subjective taste.
According to legend, Bruce Lee started his journey into Wing Chun (a form of martial arts with roots in Kung Fu, passed from teacher to student demonstrably and verbally, with little documentation) as a young teen.
He began his journey of learning with the naiive thinking that a fist is a fist. As he continued to study martial arts, he saw how different fist postures would change the energy and power of the punch, how the power would transfer and rebound. He concentrated on the posture of the fist, how the fingers and thumb locked, how the tendons and bones wrapped intricately into this amazingly flexible device that could do gentle dexterous work in one moment, and become an instrument of death in the next. The hand was INCREDIBLY complex, and when made into a fist it was even more so. He dedicated an enormous amount of time to studying the fist.
Over the years, he studied the fist - this basic offensive building block of hand to hand combat.
Years later, in a flash of insight, he realized:
A fist... is a fist.
:^D
Does this make his journey meaningless? Not at all.
I started into Vehicle Dynamics decades ago - back then, "tires are tires". Over the years I came to understand the intricacies of how this simple device - the most complex single component in a vehicle - affected EVERYTHING vehicle dynamics. Four patches of rubber the size of an adult's hand are all that connect your car to the road. In multi-dimensional modeling, the tire creates island of stability when balanced properly with the chassis.
Ever watch in wonder how a Red Bull drift car can be stable and controlled - all while the rear tires are disintegrating in smoke and the car is driving at an incredible slip angle and the driver is looking out the SIDE window to control it?
Decades later, I've discovered that even with all of this knowledge and understanding, a tire... is a tire.
A fist is a fist, a tire is a tire - but the statement BEFORE you've crossed the ocean of complexity is completely different than the statement made AFTER you've crossed this ocean and arrived at the simple answer. I guess the difference is now I know WHY a tire is a tire.
A cup of coffee is cup of coffee. But why?
;^)
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Posted Thu May 3, 2012, 1:13pm Subject: Re: Musings On Coffee Extraction, and measuring it:
Netphilosopher Said:
LOL - I don't see meaningful discussion as "argumentative" at all.
Funny you should bring that example up - I was JUST going to post an example in the area of music.
Ever hear of Glaser & Westergren?
No?
How 'bout the "Music Genome Project" Vaguely familiar?
These guys thought that if you could categorize music attributes, capturing the essence of a musical piece - ANY piece - then you could create an entire taxonomy of music.
We know it today as Pandora. Not only does it work for music, it also works for comedy. You can potentially use it for tailoring not only what you ARE looking for, but you can potentially use it to filter out stuff you absolutely HATE.
I think we are seriously OT here. An algorithm or a matrix or even a well-designed piece of software can sort and select. It cannot abstract an algebra (like George W. Boole, et al.) or examine and predict how life is created (Richard Dawkins, et al.) or create a unique musical structure (like Bach's 'Little Fugue' in A minor). It can, however, come up with a new piece very much like the Hard Rock or Slow Jazz or even 'California Easy Listening' you are used to hearing, very much in the way Apple iTunes 'Genius' helps you find something similar to other music you listen to.
Nevertheless, you must continue with your research. My 'vision' (if I am allowed to have one about what you are doing) is that it will still be convenient for me to have a cup of coffee or brew a pot for my guests, without complicated apparatus to prove it's OK.
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