Messing with the AeroPress (3)

Before I continue with these AeroPress brews, just a quick comment on the World AeroPress Championships.  I just read the technique devised by this year's winner, Jeff Verellen, here. I love reading the details of how other people conduct manual brewing.  There's a lot of creativity involved in taking something as simple as the AeroPress, or the V60, or the French Press, and making coffee in a way that is somehow different from how others have done it in the past... whilst not tipping over into obviously using a technique for the sheer novelty value.  What I especially like is when the 'rules' are bent or even thrown out completely to produce something that tastes good without disrespecting the work that has gone into bringing the beans to the brewer's possession.  Don't get me wrong... the Brewing Control Chart has vastly improved my understanding of manual brewing and hopefully helped me make better coffee.  However, I've never liked the idea of rules that restrict innovation and experimentation... so I like to think of the charts and established brew targets as guidelines rather than rules.  (But perhaps I can only get away with saying this because I'm not experienced enough to know otherwise!)

So... as the above link shows, Jeff used 17g with 270g of water... a 1 to 15.8 ratio. However, he apparently ditched the last 50g during the downpress... the link refers to that 50g as water, but I presume it is actually the brew slurry.  So that would leave 220g of coffee... perhaps actually more like 205g when you take into account water that is absorbed by the grinds and therefore doesn't pass through to the cup.

I'm intrigued by this.  It reminds me of the way some people describe a ristretto as simply stopping the shot early (which I don't agree with). When you do that with espresso I believe you're going to get a rich shot with a high TDS, but a low extraction yield (I could be wrong... that's just my current understanding). Once again it's the "over-dosed and under-extracted" scenario that annoys Mr Hoffman so much. 

I wonder... does this apply this to Jeff's AeroPress technique?  There is a difference. In an espresso basket I'd imagine the pressure throughout the puck, and the extraction of the grounds, is relatively even (granted the pressure at the top will differ from the pressure at the bottom).  Whereas in the AeroPress the grounds are floating around in the slurry, and only the grounds that are hitting the filter paper are achieving full extraction. The rest of the grinds/solids are still floating around during the downpress.  So if you don't press all the way down, then actually not only are you using only some of the water, but you're also using only some of the grounds.  The brewing ratio isn't actually 1 to 15.8.  It is a completely variable brewing ratio depending how many grounds happened to be floating and how many happened to be up against the paper filter at any moment during the downpress.  OK, I realise there is also a 'full immersion' element of the brew, not just what is going on at the point of contact with the filter, but since 50g of the slurry is being discarded (along with the extracted solids sitting in that slurry) then the effect of full immesion is reduced, and the brewing ratio is still very difficult to quantify. It is also, arguably, impossible to repeat with any level of consistency.

I'm not being critical of this brewing technique at all, by the way.  I'm just trying to understand it more by putting my thoughts down on this blog.

So whilst writing this blog post I've been finding and reading a few forum and blog posts... notable the following:
1. A thread on coffeegeeks, with some useful links.
2. One of those links was to the ever-useful blog of Marco's David Walsh, and this post (good comments below it too).
From the above reading I found that it's quite common for AeroPress brews to be updosed and underextracted (rightly or wrongly).

"So does this suggest a kind of mass hysteria among speciality coffee folks, a laziness in technique due to increasing bean quality, or perhaps that the 50+ year old standards are inadequate?

The answer is probably not 100% any of the above"  - David Walsh

Anyway, I'll keep reading but I'm now at the point where I want to at least try, as I said in my last blog, updosing my AeroPress brews.  I'll start at 1:15 and get increasingly stronger.

After that I'm thinking of going back to 1:16 and varying other parameters... grind, maybe even the grinder itself, perhaps using two filter papers rather than one to increase TDS (as suggested by Roland Glew), etc etc.  

Must remind myself where I'm going with this!  I'm initially aiming to get inside the 'ideal' brewing zone. Using that as a foundation, I'll then adjust parameters until I find out what my palate likes in terms of TDS and Extraction %.

Now, since this post has ended up longer than I expected, I'll hang on until tomorrow to post actual brewing results!