MARGINAL GAINS - THE EXTRACTION POWER RANKINGS (UPDATED!)
We take a break from our usual considered programming for something a little different;
Ladies and Gentlemen, welcome to the inaugural Extraction Power Rankings!!!!
(now updated with previous rankings in [ ] )
First off a few ground rules, after all you can’t have a chart or list without some solid reasons behind the rankings.
We're not dealing with total extraction here, that is a short list which pretty much goes like this: Coffee - i.e. your green coffee will determine the total soluble mass that you can extract.
We're looking at desirable extraction or Quality over Quantity. Sure it’s subjective but I'd like to think that a we are moving towards a common theory on what constitutes a "good" extraction. See Perger, Matt & Colonna-Dashwood, Maxwell et al for more on this.
We're approaching this strictly from a brewing for service point of view. We're not worried about cupping, quality control or similar non service stuff in this list.
It's not filter or espresso specific and I'm making some assumptions about pretty standard starting points for temp etc..
It's not exhaustive and will change as our understanding changes.
It's my list so only my opinion counts. (Just kidding! )
Sorry about the last one, got carried away for a second, it's just a list.
All right, lets do this.
1. [1] Coffee - I'd like to think that this is pretty self explanatory, but it's still the biggest factor in quality of extraction (for my money). Simply, the better the coffee, the higher your quality ceiling. The following factors can help improve things, but a bad coffee will always be a bad coffee. I'm not even going to talk about roast, you should all know better by now.
2. [2] Water - Hopefully we're all pretty much up to speed on water now, thanks to the work of Mr Hendon & Mr Colonna-Dashwood. No? Put simply the mineral content of your water is crucial to maximising the quality of your extraction. If it gets out of balance it can lead to, frankly, undrinkable coffee. As I've found to my surprise and Maxwell explains in this talk. You should also buy this book.
3. [3] Dose - On the face of it it seems simple, of course the amount of coffee you use will have a big impact on the quality of the drink, duh! Don't forget though to consider your brewer or basket size, the strength you want to achieve, the coffee itself, they all have an impact on your choice of dose.
4. [4] Yield - Intimately linked to dose, like twins or maybe symbiotes, like that weird worm in the Wrath of Kahn. Anywho, your choice of yield indicates your chosen amount of solvent and so is key in the quality of your extraction. Often dictated by the size of the brewer for filter, but a key variable in espresso brewing.
5. [5] Grind - Linked to time in espresso brewing, how long we leave our coffee in contact with the water seems an obvious factor in extraction quality. The quality and size of our grind can drastically effect our extraction quality. After all our % is simply an average of all the %'s from all the various sizes in our grind. Note to self, invest in a good grinder.
6. [9] Distribution - See Below. Pressure can help even this out, but if your espresso dose is unevenly distributed both vertically and horizontally, you're reducing your flavour ceiling (I just thought of that, flavour ceiling, I like it) [In other news my modesty is my best quality]
7. [8] Pressure - Quality is linked to evenness when it come to extraction. Pretty much specific to Espresso (with one caveat), there appear to be limits between which we see little difference (9-12 bar ish). I've seen first hand how a lower pressure can improve both the quantity and quality of extraction, have a read. Back to that caveat, The Aeropress. By pushing the water through the coffee we exert a small pressure, this creates turbulence in the slurry and so will affect your extraction. Take it slow to linearise your flow. (If we push slower we'll get less shear stress at the aeropress walls and so less turbulence and a smoother flow)
8. [6] Time - If our dose and yield help us set how much extraction we have, time helps us determine how much of "what" we have. In other words all extractions are not created equal, how we get there and how long it takes counts. In espresso this helps tune the finish and so find that tipping point between a quality extraction and over extraction.
9. [7] Temperature - Solvents are more efficient at higher temperatures. This should probably be higher (or lower depending on your point of view) but I'm giving you all the benefit of the doubt and assuming your going to be within a sensible temperature range.
10. [10] Filter - Both basket choice for espresso and filter choice for brewing will have an impact on your flavour ceiling ( I'm sticking with it, maybe it can become a thing). Your basket choice will affect the evenness of your extraction, whilst your choice of filtration method can influence acidity, body, clarity and sweetness of your brew. Like the Old Templar said in The Last Crusade "Choose wisely".
11. [11] Tamper - Obviously espresso specific, it can affect your puck density and evenness of your extraction, There is some discussion on how much though. Read these things.
C'est Fin.