AeroPress with Hario Mini Mill hand grinder

NB After reading this blogpost you may like to read a follow-up post written over a year later. See here.

I got a Hario Mini Mill hand grinder recently, because I've decided to keep my Gaggia MDF grinder just for espresso. Changing between an espresso and a drip or press grind used up quite a lot of beans to get it working right. So the Mini Mill is just for non-espresso brew methods.

So now I need to work out what grind settting on the Mini Mill works best for each brew method. Here's a little picture of different grinds. Unfortunately the preferred AeroPress grind isn't mentioned but I believe it is slightly coarser than espresso.



There are actually no visual settings on the grinder.  You just turn the nut and feel it click as each setting slots into place.  But I'm taking the approach of starting from a completely 'closed' position (i.e. the finest grind), then counting back the number of clicks from there as I turn it anti-clockwise.

So today I tried the following on the AeroPress:
Beans: Columbian Excelso Bucaramanga Municipality, from Coffee Chocolate & Tea in Glasgow
Days since roasting: 18
Grinder Setting: 3 (very fine)

I also pressed the AeroPress all the way down, rather than stopping (as I did last time) once I heard the hissing sound.  This brought the crema-like foam through the filter and into the cup.

The resulting coffee was strong and very bitter - not at all what I'm looking for from the AeroPress.  Typical signs of over-extraction, so I reckon the grind was too fine.  I also decided to ditch the idea of allowing the crema-foam to enter the cup, as I'd imagine it is filled with bitter compounds.

I tried again, this time increasing it to setting 5.  The coffee was less bitter, and the flavours of the bean did start to show themselves, but still too strong and not sweet enough for my own palate.

I read THIS thread on the coffeegeeks forum, and two posts are saying that 6-10 clicks is the right zone.  I'll therefore try 8 next time and then update this blog post.

1ST UPDATE: 8 clicks ... I'm drinking it right now... Still no sweetness, but the strength has evened out to an acceptable level.  Actually I think that what I'm tasting now is acidity rather than bitterness.  Yes... it's cooling now and there's a tart, lemonjuice taste coming through.  OK, I'm thinking maybe I've found the right grind setting for AeroPress (8-ish), but I'll try a 10 just to be sure. 
I'm struggling a little with this.  I'm going to try different beans anyway just for peace of mind.

2ND UPDATE: 10 clicks.  Much better.  I also changed the beans to Formula 6 by James Gourmet Coffee, an espresso blend.  Strong (moreso than drip coffee), balanced as I might expect an espresso blend to be.  I'm not good at picking flavours out yet, so I'll cheat and have a look at the roaster's comments:

"I am finding that with our F6 cappuccinos you can get great toffee and caramel notes with nuts lots of milk chocolate right now.The shots are strangely sweet, fruity & rich with great body."

Yeah, although it's not brewed as espresso I can still get a recollection of a fruit taste, like some kind of sharp berry but without all the sweetness of the actual fruit, like I get when I bite into a blueberry. But maybe it's in my mind.
Anyway, approx setting 10 on the Hario Mini Mill for AeroPress brewing.

(By the way my Hario arrived without English instructions.  Here are some dual-language instructions I found online.)

*** EDIT: 23 Feb 2012 ***
I can't help noticing that this post has been linked to on a few sites and read by quite a few people. I'd therefore just like to update it with some more recent findings.  I've been using setting 5 on the Hario Mini Mill, which increases the brew strength, but to compensate I've used cooler brew water, specifically 80 degrees C, using a brewing ratio of around 1g of coffee to 15.5g of water.