# AeroPress and hand grinder combo



## MikeHag

I was asked for tips on brewing with an AeroPress/Porlex combo. I don't have a Porlex but I've done some work with my Hario Mini Mill to see if I can get something good out of that combination. Here's a blog post about it incase it helps anyone.

http://haggieslab.blogspot.co.uk/2012/06/aeropress-hario-mini-mill-grinder-and.html


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## Earlepap

A good read Mike. Fancy lending me your refractometer?


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## MikeHag

Cold... dead... fingers!!

I do believe Glenn's coffee consultancy business has one that he has previously offered to lease out though.


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## tribs

Interesting stuff.

I think I read somewhere that using a lower temperature in the Aeropress was partly to reduce risk of leaching of undesirables from the plastic.


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## MikeHag

The reason I have used lower temperatures in the past is that it reduced bitterness. But I now believe that's not necessarily the right approach as it just results in an underextracted brew that is inoffensive (because it isnt bitter) but nothing special. I very much doubt the plastic particles or chemicals would dissolve in water of these temperatures in any material quantities.


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## garydyke1

Very good Mike. So you essentially ended up with the UK Brewer's cup recipe and parameters. I find best results with the aero (taste wise) are similar ball park. Coarser grind however , less aggitation and slightly longer steep.


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## JamesG

MikeHag said:


> I very much doubt the plastic particles or chemicals would dissolve in water of these temperatures in any material quantities.


There was a debatable risk with the original (cloudy blue) model could leaching undesirables. Although nothing, as far as i'm aware, was proven.

The clear model is fine though.

http://aerobie.com/Products/Details/AeroPressMaterialsDescription.htm

http://worldcoffeeproject.com/187/new-aeropress-but-whats-it-made-out-of/


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## MikeHag

garydyke1 said:


> Very good Mike. So you essentially ended up with the UK Brewer's cup recipe and parameters. I find best results with the aero (taste wise) are similar ball park. Coarser grind however , less aggitation and slightly longer steep.


Cool! Didn't know that about the brewers cup thing. So how long do you steep for? 4 mins seems an age to me with the AeroPress.


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## Milesy

garydyke1 said:


> Very good Mike. So you essentially ended up with the UK Brewer's cup recipe and parameters. I find best results with the aero (taste wise) are similar ball park. Coarser grind however , less aggitation and slightly longer steep.


You are suggesting longer than 4 minutes contact time that he already has?

I am still experimenting but I find that any more than 2:00 contact time including stirring and plunging brings out that bitterness.

I am still however (as I mentioned in my musings thread) getting this reoccuring issue where plunging takes incredible effort regardless it seems of the parameters.

My cup this morning was 8 clicks and the grind seemed to me half way between espresso and drip.

10 seconds stir, 1 minute steep, stir the grounds from the crust back down again, press in about 30 seconds.

To press in 30 seconds I am pressing pretty hard, and I am pretty strong. I have also tried to just use enough force to allow the plunge itself to do the work but it didnt make any difference - that took over a minute to press and was still some effort.

I just tried making more course up to 11 clicks. 10 seconds stir, 1 minute steep, press in 30 seconds. The plunge was still hard but not as hard but the grinds were very inconsistant - could see some saucer sized grinds in there and the cup was very weak (in milk) has left a very horrible bitterness in my mouth!


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## Milesy

p.s. Does anyone know why on earth I am getting so much resistance with the course grind? Inconsistent grind? Someone mentioned fines in the other thread?

Would it make a difference on whether I rinse the filter paper and cap through with cold or boiling water?


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## MikeHag

The most common cause is obviously the grind being too fine, but sounds like you know that.

Also a good idea is to invert the AeroPress so that the filter isn't placed on until the last second, and then when it is flipped the right way around there is no chance of grinds having been sat on the filter paper and become 'fused' on.

I don't think cold or hot makes a difference to flow rate - just make sure you rinse it









Here''s a photo of the grind size I used in my blogpost. Left is the Mini Mill, right is the Guatamala grinder, slightly larger. I too have to press slowly ... approx 30 secs.


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## Milesy

My last grind at 11 clicks is much courses than any of them. It is more like someone has hit the bean with a hammer rather than ground it.

It only took 30 seconds with some hard effort from me. I am 13 stone and pretty strong. The result was very bitter.

I always do inverted.


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## MikeHag

Do you wet the chamber and rubber seal before inserting? As well as helping make the seal it may also help it slide.


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## tribs

Milesy, are you using a porlex mini?

I actually grind finer than 8 on mine. Also give it a try non-inverted.


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## jimbow

Great post Mike - I have always been surprised at how relatively difficult it is not to under extract with the aeropress. I did notice that the metal filter makes a big difference for me, more resistence in the plunge and much more acidity.

Sent from my HTC One X using Tapatalk 2


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## garydyke1

Milesy said:


> p.s. Does anyone know why on earth I am getting so much resistance with the course grind? Inconsistent grind? Someone mentioned fines in the other thread?
> 
> Would it make a difference on whether I rinse the filter paper and cap through with cold or boiling water?


Probably fines, these clog the paper


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## Earlepap

MikeHag said:


> Do you wet the chamber and rubber seal before inserting? As well as helping make the seal it may also help it slide.


Forgive me for being puerile, but this made me titter like a school girl.


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## Monkey_Devil

This is great to read Mike, thanks for taking the time to document your findings for us to learn from

. I'll be using your method tomorrow to try and zone in on my ideal.


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## Milesy

MikeHag said:


> Do you wet the chamber and rubber seal before inserting? As well as helping make the seal it may also help it slide.


Not intentionally anyway but that is certainly worth a try. Sorry for the hi jack


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## MWJB

Milesy, have you tried trying the CoffeeGeek French press trick? Rather than stir your crust back down, spoon it out, then plunge? (Just a suggestion...never tried it with the Aeropress myself).

Regarding Aeropress underextraction, Mike what kind of refractometer readings would you get grinding finer & going closer to the HasBean/Aeropress factory method...not suggesting this is going to give you a preferable result in the cup, just curious...I mean if we are moving away from the intended purpose/technique (vast majority of folk are using it as a cleaner FP), doesn't it follow there will knock on effects from moving goalposts? E.g. As I would expect if I, for example, ground fine, plunged after 30 seconds & poured with a FP? Again, just curious from a spectator's point of view (AP mothballed at the mo').


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## MikeHag

HasBean's video recomments a filter grind, which is coarser than I used in the blog so it wouldn't increase extraction. Conversely, a finer grind than I'm using now won't work at all... it wouldn't plunge. The filter would burst.

There are a few things about the Has Bean video that although they are absolutely fine, don't work for me personally. First it says use 17g in an inverted AP. If you invert the AP and use 17g then you cannot fit enough water in to give you a brewing ratio that will result in a Gold Cup extraction. I just like adhering to Gold Cup in most cases, as it gives a benchmark for controlled brewing.

For example, in my blog I used 14g of grinds to 230g of water. With the 18.41% extraction yield that gives, the coffee strength (TDS) is medium... 1.26%... right in the middle of the Gold Cup 'ideal' range. But if you increase the dose to 17g, keep the same mount of water and extract to the same yield of 18.41% then the coffee must become much stronger... 1.58% (if you can get it that high, which might be a struggle). So even if you extract it well, you're creating a concentrate that you must then water down, as Steve says in his video. It's bypass brewing, a completely different brewing technique from how most people brew. A tiny difference in the amount of water you dilute it with results in a massive difference in the strength of the coffee, so it pays to be a bit careful with how much you add.

Nothing wrong with bypass brewing but it's not my thing.

However, I'll give it a try with the refractometer and see what the pre-dilution readings are like







I could be making wrong assumptions about something.


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## JamesG

A lot of the winning recipes at the World Aeropress Championship don't conform to the Gold Cup: http://worldaeropresschampionship.wordpress.com/recipes/.

Not sure why this is. David Walsh wrote a post on it way back: http://theotherblackstuff.ie/placesandfaces/gold-cup-pyrite-grinder/.


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## MikeHag

Don't get me wrong... I don't believe in slavish adherence to Gold Cup. Taste is what matters. But i'll bet you almost everyone who took part in those brewing competitions used the mojo to get into Gold Cup as a starting point and then tweaked the recipe from there. Some coffees are better beyond the Gold Cup range. But if someone asks me for advice then I'm going to try to get them into the Gold Cup first. Updosing is a wasteful way to compensate for bad technique.


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## JamesG

I agree with you - it's a good reference point.

It'll be very interesting to see what's changed when the Gold Cup Research Group finally conclude their research and what David Walsh discovered from his little side project.


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## MikeHag

I contributed to it for a while but it began to seem a waste of time as most of the time Gold Cup was best and the outliers were naff. It may provide some nice insights though, I hope, and perhaps a foundation for a more detailed survey afterwards. Some important things are missing from this first one. But it's a start.


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## MikeHag

For anyone who read this blogpost, I've made an update to it today. More interesting stuff regarding the impact of water quality upon the extraction.


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## JamesG

Have you tried mixing the Highland Spring water with the new water source yet? You could call the hybrid: Water 2.0


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## Earlepap

What is this mysterious other water source?


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## garydyke1

We have been moved back onto seven trent water after several months on a private on-site natural supply.

Safe to say the chemistry is way different: espresso is tasting better...brewed coffee = cant make a single decent brew...back to highland spring


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## MikeHag

Earlepap said:


> What is this mysterious other water source?


Ha! For the first time yesterday I filled some empty Highland Spring bottles with water from our cafe premises and brought them home. Tested the water with the TDS meter and then did some brewing. Big sigh of relief with the results as possibly don't need an RO system now and it may be just about spot on for coffee. But I've sent an email to http://www.dwqr.org.uk/ to see if they can confirm other components such as calcium, magnesium, bicarb, sodium, pH etc. These are the things (I believe) that are making such a difference to the extraction and flavour, not the total TDS figure.


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## MikeHag

garydyke1 said:


> We have been moved back onto seven trent water after several months on a private on-site natural supply.
> 
> Safe to say the chemistry is way different: espresso is tasting better...brewed coffee = cant make a single decent brew...back to highland spring


Could you get hold of the readings that severn trent water took? They are usually available to the public I believe.


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## CoffeeJohnny

Found out over the last few days my mains water is not good for espresso so have switched to bottled, the tank on the back of the machine is pretty well insulated too so this means I can keep a relatively decent amount of water in reserve too, question though, is it worth re filtering bottled water through perhaps a britta or something similar?


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## MikeHag

Depends on the bottled water, John. If you're using volvic or highland spring I'd say not needed. Have a look on the label. Dry Residue is the same as TDS, I'm told. Here are the SCAA standards:









Aim for something with a low Bicarbonate reading (see "total alkilinity" above as a target)

However you do it, I personally wouldn't filter using a Brita. I've heard a few things about them lately that have reinforced what the SCAA water handbook says about ion exchange.


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## garydyke1

MikeHag said:


> Could you get hold of the readings that severn trent water took? They are usually available to the public I believe.


Im sure they are, and by tap standards we have some great water from the Welsh mountains in Brum ''Birmingham wine /council pop''.

However some factors here :

1. Id adjusted my brewing for the water I was using, im sure re-dialling eveything in again with this new water could get some great results again

2. The private supply wasnt chemically treated, I can TASTE the chemicals in Seven trent supply, so theres some tangable 'taint' to the end cup

3. We are moving soon so cannot be bothered to adjust everything again, I know Highland Spring can give me similar results to the old water.

4. Improvement to espresso is probably a happy accident


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## Earlepap

Congrats on the cafe having nice water plumbed in Mike.


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## MikeHag

Cheers Gary.



garydyke1 said:


> I can TASTE the chemicals in Seven trent supply, so theres some tangable 'taint' to the end cup


Chlorine is a disaster for coffee, if it's in there. Just for info, a carbon block filter removes the chlorine.


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## garydyke1

MikeHag said:


> Cheers Gary.
> 
> Chlorine is a disaster for coffee, if it's in there. Just for info, a carbon block filter removes the chlorine.


We have one of these for the new house, pointless installing here.

Best I move in , get settled & then start all from scratch


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## MWJB

Could a relatively low TDS with the Aeropress be partly due to the pushing of the water through the grinds, thus leaving less retained water in the grinds as compared to other brew methods? Part of the nature of the beast? ...Thus blowing my earlier ascertion that "the plunger may not have a direct influence on brew" clean out of the water, but by the same token perhaps suggesting that letting the brew drain by gravity alone might nudge up TDS slightly for a given extraction ratio?


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## MikeHag

The theory is that there is more agitation (and hence greater extraction) when the water is being forced against something e.g. a filter. The analogy is that if you consider a river where the water is flowing freely, there is very little turbulence compared with placed where a log blocks the flow.

I'll try anything once tho!!


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## MWJB

Mike Hag wrote: "Don't get me wrong... I don't believe in slavish adherence to Gold Cup. Taste is what matters. But i'll bet you almost everyone who took part in those brewing competitions used the mojo to get into Gold Cup as a starting point and then tweaked the recipe from there. Some coffees are better beyond the Gold Cup range. But if someone asks me for advice then I'm going to try to get them into the Gold Cup first. Updosing is a wasteful way to compensate for bad technique."

This thread has really fired my interest with regard to my Aeropress, previously I tended to mostly use the handy gadgets that came with it...But I have a question (accepting the huge diversity in AP methods & dosing quoted in successful recipes)...inverted, the AP is just a cylinder, like a French Press. As far as extraction goes, you can do pretty much what you do with the French Press, as well as the shorter steep times & finer grinds that seem more typical (Gary's approach excepted). The French press apparently has issues with extraction, so if brew ratios of over 60g/l are commonplace here, why would we avoid doing the same with the Aeropress. Aren't the Gold Cup standards aimed more at filter brewing? Perhaps adhering too closely is banging a square peg into a round hole to some degree?

I have made tasty brews in the AP at ~60g/l, but if adding a couple of grams of grinds gives the desired result, why beat yourself up.


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## MikeHag

Several points here.

A) "French Press has extraction issues" - does it? I've never found any.

B) Gold Cup isnt for filter. It's for all brewed coffee regardless of brewing device.

C) Gold Cup is not about a brewing recipe of 60g/L. It is much more flexible than that and the range of recipes is wider. You can dose higher (or lower) than 60g (within an acceptable range) but as you add more coffee then to stay within "typically" tasty brew parameters you have to either increase the coffee concentration (which risks tasting overdeveloped... heavy) or reduce the extraction yield (which risks dropping into that sharp, underextracted zone).

There is no square-peg-round-hole about Gold Cup. It just isnt that inflexible. So often I read statements that suggest there is a lot of misunderstanding about Gold Cup standards. I think there would be more acceptance of using it if more people knew how the Brewing Control Chart works. It's a very simple diagram.

I think if anyone wants to use updosing to make the coffee taste more acceptable, rather than adjust their brewing technique, go for it. If it tastes good... fine. My own reasons for using established brewing standards as a starting point are (i) I find that 90% of the time Gold Cup brews (whether lower or higher than 60g/L) taste better than outlier brews (that's why I gave up contributing to David Walsh's research); (ii) it is more economical. I use less beans; (iii) it makes brewing more repeatable.


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## MWJB

I've seen several FP recipes where doses of

I understand that Gold Cup isn't a single brew ratio/TDS/extraction yield point & that your bid to raise TDS in the AP was driven by taste rather than a requirement to meet a theoretical idea/datum...but it did, nevertheless, seem to be an objective in your blog post.

EDIT : I am actually reading the SCAE page on the Gold Cup right now & it does several times mention the Gold Cup with respect to filter coffee specifically and at 50-65g/l, 18-22% extraction.


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## MikeHag

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Fair point regarding the word filter. But The term filter coffee has been used by some over the past few decades as a catch-all for 'everything but espresso'. Technically French Press and AP and both filter brewers too.

Whether they share brewing quirks - maybe as a function of their design - I don't know. But if so then we would also have to point the finger at all full-immersion brewing methods, wouldn't we? A Syphon is very similar to an AeroPress in it's brewing and filtration, for example.

In the blog I used (and always use) a combination of tasting and controlled brewing to achieve taste rather than uncontrolled/unmeasured brewing. Stats aren't a goal for me. They are a routemap for achieving a goal, just as a chef would use a probe thermometer to prepare a steak. He/she could make it rare, medium rare, well done etc, whicj is similar to making coffee at different extractions. His/her use of technology and methodology doesnt mean that temperature is more important than taste, and I take the same stance with regards to people using brewing control/gold cup. So yes, my objective was to reach a particular extraction... and then taste it, which I did include in the blog too.

Some people use 75g, some use more/less. Some of my friends used 2-3 teaspoons in a litre, which equates to around 25g, and they have never questioned how it tasted! If they ask me for advice I'll say use 60g because it is more likely to taste good than 25g. Maybe 55g would taste even better, or 75g - with that particular coffee.

Ultimately I think if you are a coffee 'geek' like most of us on here are (surely it's kinda geeky to join a coffee forum







) and lucky enough to have a grinder to change particle size, or have a spoon to increase agitation, or can use slightly colder/hotter water, or can wait an extra 40 seconds of steep time, all of which can increase/decrease the extraction without changing the dose, then why not try those things first rather than just up/down-dosing? I have nothing against higher/lower doses outside the gold cup zone - I just think that 9 times out of 10 they are a cop out.


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## MWJB

Thanks Mike,

As ever, - a solid, thought provoking & ultimately sensible philosophy. 

I don't want this to start looking like some sort of cross examination, but I am struck by certain differences between typical syphons & AP/FP, in that they have significantly more cross sectional area (yes, "geek" carries no shame for me, as you have probably guessed), you only need a vessel 80mm wide to double the Aeropress's CSA (I do alot of measuring & make a lot of charts, admittedly some are revealed as total bunkum) I just wonder whether factors like wider brewers naturally lend themselves to more efficient extraction at a given brew ratio/quantity.


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## MikeHag

Yeah, it's an interesting subject. Wide cupping bowls are said to be better as they ensure greater exposure of the grinds to the water. Not sure if there is any evidence to support or refute that tho. Seems logical, and might explain why a narrow tube such as the AeroPress might struggle with even extraction. Would love to know more about this.


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