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Science Time with Dr Hendon


Barista Hustle

September 5 · Issue #83 · View online
Views and news about the brews. Unique and relevant information for coffee professionals and enthusiasts.

Science Time with Hendo
Specialty Coffees loveable science mascot and all-round good guyChristopher Hendon posted what you might call an AMA in the Barista Hustle Facebook group this week prompting any and everything science-y to be thrown his way.
The following is a distillation of that thread .

Questions are summarised in bold with Chris shortened response is beneath. Direct quotes are in quotation marks.
Whats the situation with transgenic agriculture?
You could try to modify a coffee leaf to resist something like rust (roya), but the leaf is also where the delicate process of photosynthesis happens, and you dont want to screw up photosynthesis. Its too early to speculate whether were skilled enough to avoid long term problems.
Coffee is hygroscopic (soaks up water). Is this why parameters change during a bar shift?
Every small variable in coffee seems to matter, and its nearly impossible to separate humidity from other variables like temperature. Theres only one way to find out: do a proper experiment.
When is best to consume a coffee after roasting in relation to ageing, degassing, and oxidation?
CO2 continuously leeches out from the dense coffee cells from the moment its created during roasting. CO2 could be dissolved into brewing water, reducing the pH - whether this tastes good to you is up to you. Same goes for all the other compounds that are slowly escaping the bean.
Oxidation is a separate issue. It will happen, but only if you store the coffee in an environment with plenty of oxygen. Lowering the storage temperature will significantly slow this effect.
Ageing is a process which can see the reaction of fats and other unsaturated hydrocarbons, and oxygen rich molecules, undergo chemical reaction which yields new molecules that could only be obtained with time (ie. very slow).
All together, this is very anecdotal and personal. Its best for you to test and taste and form your own opinions.
When roasting, does the temperature or the time matter more for chemical reactions?
Chris responded with a detailed graph/image here (non-facebook link).
Hitting a certain temperature is the key for most reactions, but they dont necessarily happen straight away. Once youre at or above that temperature, applying more heat will make that reaction happen faster.
Why dont all grinders use the same number scale?
Theres way too many variables to make this work. Also, Its phenomenal how useless the grinder settings are.
Can we quantify the chemicals in a coffee that are making specific flavours?
We could use high level analytical techniques. These might be useful.
Its hard to tell whether the biological response you are having is due to the presence of one molecule, or two acting together, or 30. You can definitely draw some fun correlations between flavour descriptors and chemistry.
Has there been any research/thought on the importance of dissolved oxygen and its impact on brewing?
No idea why dissolved oxygen would make any difference given it is non-reactive with most things. More importantly, its content in average water is like, <1 ppm.

A big thanks to Chris for being a knowledgable, generous, and humorous host.
Language Assumptions
This passage from Mark Forsyths The Elements of Eloquence really hit home for me:
地djectives in English absolutely have to be in this order: opinion-size-age-shape-colour-origin-material-purpose Noun. So you can have a lovely little old rectangular green French silver whittling knife. But if you mess with that word order in the slightest youll sound like a maniac. Its an odd thing that every english speaker uses that list, but almost none of us could write it out. And as size comes before colour, green great dragons cant exist.
It made me wonder what were saying as coffee professionals that seems perfectly normal to us, but could be hard to decipher or re-communicate as a consumer? Ordering coffee and our demands for customers desires to fit into standard drink categories is the first one that came to mind.
How can we do better?If youve got ideas or frustrations, I posted it yesterday in the ol FB group.
The BH Subscription
This months subscription coffee is being packed and shipped to over 40 countries today from the fancy new fulfilment centre in Hong Kong.
If youre a subscriber, expect a tracking number and salivating coffee details in the coming days.
If youre not, doget on board for next months delivery!
What do you want to know?
As you can see 儭 Im now selling things as Barista Hustle. This means I can spend more time researching, learning, and sharing it with you: the community. This is exciting!
So what do you want to learn? What would make this email more valuable to you? What cant you ask on the facebook group or forum? Im super keen to know! Just reply to this email and let me know.
See You Next Week!
To the boundaries of coffee,

Matt Perger
Barista Hustle
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