Any real data on espresso compounds extracted over time?

Want to talk espresso but not sure which forum? If so, this is the right one.
User avatar
decent_espresso

#1: Post by decent_espresso » Sep 27, 2015, 8:17 pm

I've been scouring the net to try and find real data about what is extracted, over time, from an espresso shot, presented in a simple and useful format.

What I'm really trying to do is to figure out if at rough timing intervals, there is something meaningful I can say about what's coming out of the pf at that moment. Many people don't know that caffeine is not very soluble, for instance, and another common unknown factoid among amateurs is that bitter tannins really rise quickly after 30 seconds.

This chart is pretty famous:
Image

and I found this one today:
Image

Are these two charts based on real data? Can anyone find a ref to the data?

What does it mean in these charts for intensity to be 100% and then drop down? Wouldn't each of the 4 categories go to 100% and stay there?

I read these charts to be giving me "extraction percentage rate of this group per second", but that's just my trying to make sense of it.

Of course, there is this famous chart of Illy's:

Image

but it's not really that helpful when making a shot as it doesn't talk about caffeine or bitterness.

Marcelnl
Supporter ♡

#2: Post by Marcelnl » Sep 28, 2015, 2:38 am

When reading some abstracts, or rather snippets, on the ZHAW website I saw tbis setup where they did an in line analysis of coffee being extracted but I can't recall is they did a full spectrum of just a few compounds and what method they used.
Anyhow, the differences would be large as varieties differ wildly in caffeine content so I'm not sure to what use you could put that knowledge.

The graphs read to me as extraction over time and they drop due to the fact of the 'compound' being extracted.
LMWDP #483

User avatar
canuckcoffeeguy

#3: Post by canuckcoffeeguy » Sep 28, 2015, 8:39 am

I'm assuming when, what, and how compounds are extracted are influenced by a number of factors: bean varietal, roast, brew temp, temp profile, pressure profile, grind, distribution, basket, tamp, grouphead, off gassing level of bean etc. But I have no scientific expertise to back this up.

However, I'm also assuming some general conclusions can made about compound extraction throughout a shot. And we've seen this anecdotally via the test of thirds.

But I suspect detailed analysis would show a variety of results depending on the intermingling of espresso making variables. We know this anecdotally by tasting our shots.

But I could be wrong. Maybe it's possible to create a standardized extraction profile for compounds.

User avatar
Marshall

#4: Post by Marshall » Sep 28, 2015, 12:08 pm

decent_espresso wrote:I've been scouring the net to try and find real data about what is extracted, over time, from an espresso shot, presented in a simple and useful format.
What goes on in coffee extraction is so complex it does not lend itself to simple visual representations. I also think it is a mistake to isolate caffeine and make brewing recommendations based on its extraction rate. The issue is one of balance and how well caffeine's bitterness complements all the other compounds being extracted at the same time.
Marshall
Los Angeles

User avatar
doublehelix

#5: Post by doublehelix » Sep 28, 2015, 12:22 pm

I think you'll need to plow through the food science literature and then "extract" your own simplified guidelines. I've been wonderfully amazed by the level of sophistication presented by such literature, and how over the past decade computer simulations have become routine in this field. In fact, some of the best theoreticians, especially in Europe, work with the food industry.

Question: Do "reference" coffee materials (beans, roasts, etc...) exist for anyone to purchase, aside from instant "coffee?"

User avatar
Marshall

#6: Post by Marshall » Sep 28, 2015, 12:36 pm

doublehelix wrote:Question: Do "reference" coffee materials (beans, roasts, etc...) exist for anyone to purchase, aside from instant "coffee?"
Yes. The Coffee Lexicon (recently developed at Kansas State University with guidance and funding from World Coffee Research) has commonly available reference material for each flavor. The most talked about has been Oregon canned blueberries for that Yrgacheffe "blueberry note." Lindsey Bolger's presentation at April's SCAA Symposium is well worth watching: https://www.youtube.com/watch?t=8&v=YCTlk1uj1nM
Marshall
Los Angeles

Marcelnl
Supporter ♡

#7: Post by Marcelnl » Sep 28, 2015, 12:41 pm

https://www.google.nl/url?sa=t&source=w ... J_fsRukLAA

Fwiw though, I do think it is a waste of time generalizing this sort of data in a world of variables beyond your control.
LMWDP #483

baldheadracing
Supporter ♡

#8: Post by baldheadracing » Sep 28, 2015, 12:59 pm

Some research previously posted; whether the linked article and book are "simple and useful" is perhaps a function of the reader :) :

Pump vs. Lever - chlorogenic acids [pdf] + "Coffee in Health and Disease" [book preview]
What I'm interested in is my worst espresso being fantastic - James Hoffmann

User avatar
canuckcoffeeguy

#9: Post by canuckcoffeeguy » Sep 28, 2015, 1:15 pm

On the first chart, the only certainty is shots begin darker and get lighter :D The certainty ends there.

And as we've seen in countless HB discussions, the concept of blonding alone is controversial. Uttering the very word might get you flogged in some third wave circles. :wink:

Beyond that it's Star Trek particle replicator meets coffee. In the meantime I'm going to keep on tasting and adjusting.

User avatar
decent_espresso

#10: Post by decent_espresso » Sep 28, 2015, 1:19 pm

baldheadracing wrote:Some research previously posted; whether the linked article and book are "simple and useful" is perhaps a function of the reader
Thanks for that link. I found an older HB thread on caffeine extraction over time, here:
Does a long espresso contain more caffeine than a short one?

Here's the caffeine chart from that thread, extracted apparently from Illy's book.
Image

Just bought a Kindle version of the Illy book, and will start looking through that.