primacoffee Senior Member Joined: 19 May 2010 Posts: 36 Location: Louisville, KY Expertise: I live coffee
Espresso: Dalla Corte Evolution 2grp Grinder: Mazzer Mini Vac Pot: Yama Siphon Drip: V60, Chemex, Kone, Wave
Posted Thu Jul 12, 2012, 10:34am Subject: DIY Aeropress Cold Drip Brewer for Under $30 - How To
We recently discovered this delightful idea on a coffeesnobs.au post and tweaked it to our parameters. We've been experimenting for a couple of days now and so far have had great results!
Empty bottle and cut off bottom.
Remove bottle’s cap and puncture with needle. Replace cap. Test flow by filling with water and watching rate, aiming for about 40 drops per minute.
Wet filter and assemble Aeropress, filling with 45 g of medium-fine ground coffee.
Moisten grounds and stir gently, subtracting water used from total water dose. Level coffee bed with finger.
Trim second filter to fit inside of Aeropress and place atop coffee bed, pressing softly to level.
Place Aeropress on jar and mount bottle on top.
Fill bottle with 300 g water and 200 g ice.
Thought you would enjoy it. We're also experimenting with different filter types (Able Disk-Fine, etc). Let us know if you've had success with something similar!
Posted Thu Jul 12, 2012, 11:00am Subject: Re: DIY Aeropress Cold Drip Brewer for Under $30 - How To
BTDT. It's very close to my funnel cold drip brewer (sorry, no pic).
Be sure to post some beverage strengths when you're done. I find a significant amount of grounds absorption and sometimes some less-than-expected (but still stronger than hot brewed).
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Doesn't matter to the end drink, in my experience. At that slow percolation, coupled with the low temperature, retention of the heavier fats which are never heated enough to be emulsified, there will be pretty much zero effect if you squeeze the extra 1-8ml out of the grounds or not - except since it's percolation the strength at the end is much lower than the strength in the cup. That extra will dilute (just barely) the coffee produced.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
yamhill Senior Member Joined: 1 Feb 2009 Posts: 35 Location: Portland, OR Expertise: I love coffee
Espresso: Silvia PIDed, Nuova... Grinder: Mazzer Major Vac Pot: yama Drip: hario and chemex Roaster: hot air & drum in the works
Posted Thu Jul 12, 2012, 2:54pm Subject: Re: DIY Aeropress Cold Drip Brewer for Under $30 - How To
Thanks for sharing a new take on cold extraction.
I have a bunch of questions. I've used Toddy some. How does the strength and taste of the extraction with this method compare to Toddy? If I recall correctly the Toddy-recommended ratio of grounds to water is roughly 50g / cup of water for 12 to 24 hours. At 45g / 2+ cups water (assuming that the ice all melts), the coffee to water ratio, time, temperature are all different. 45g is three double shots in my Silvia. Is 1/3 of this cold brewer output a good stand-in for a double shot?
Also, I would love to hear more details on the "why" behind some of your guidelines. For example, here are a few more geeky questions? Is the ice important to slow the flow of water or temperature or both? What temperature should the "pre-infusion" water be in the moisten and stir step? What effects do you get with coarser of finer grinds? Does the top filter do anything beyond slowing and dispersing the water drops?
oktyone Senior Member Joined: 26 Apr 2012 Posts: 26 Expertise: I love coffee
Posted Thu Jul 12, 2012, 5:23pm Subject: Re: DIY Aeropress Cold Drip Brewer for Under $30 - How To
I've tried this before, works good except you can't control the dripping speed (extraction), sometimes it stops dripping, sometimes it drips too fast, i've used an ABLE disk (ver.2) and a regular aeropress paper filter on top of the coffee column to help distribute the water evenly.
Inspired by another experiment on a HB forum post i went to a local pet/aquarium store and got some aquarium tubing and dripping spigot and installed it to the plastic bottle cap, works wonderfully and the dripping speed is totally controllable, it tends to go slower as time goes by, but it can be easily adjusted by opening the valve a bit more every once in a while. Still unsure about the taste though, but i love the theatrics aspect of these brewing method.
primacoffee Senior Member Joined: 19 May 2010 Posts: 36 Location: Louisville, KY Expertise: I live coffee
Espresso: Dalla Corte Evolution 2grp Grinder: Mazzer Mini Vac Pot: Yama Siphon Drip: V60, Chemex, Kone, Wave
Posted Fri Jul 13, 2012, 7:05am Subject: Re: DIY Aeropress Cold Drip Brewer for Under $30 - How To
yamhill Said:
I have a bunch of questions. I've used Toddy some. How does the strength and taste of the extraction with this method compare to Toddy? If I recall correctly the Toddy-recommended ratio of grounds to water is roughly 50g / cup of water for 12 to 24 hours. At 45g / 2+ cups water (assuming that the ice all melts), the coffee to water ratio, time, temperature are all different. 45g is three double shots in my Silvia. Is 1/3 of this cold brewer output a good stand-in for a double shot?
Also, I would love to hear more details on the "why" behind some of your guidelines. For example, here are a few more geeky questions? Is the ice important to slow the flow of water or temperature or both? What temperature should the "pre-infusion" water be in the moisten and stir step? What effects do you get with coarser of finer grinds? Does the top filter do anything beyond slowing and dispersing the water drops?
1) Toddy is considered a "concentrate", so the consumer typically dilutes it with either water or milk before consuming. Cold brew methods like this one do not yield a concentrate, but a ready-to-drink brew. Sure, you can add water or milk — no harm done — but that's not the point.
2) It's difficult to compare the output of this device to espresso, as they're very different things. For one, this method doesn't implement any pressure. Also, the strength is different. For the same dose of coffee (45 g), espresso uses much less water than the cold brew tower. Even the extended brew time (compare espresso's <30 seconds to cold brew's 2-4 hours) doesn't make up for this.
3) The ice is included to keep the water cool throughout the entire process. The goal is to have ice floating in the water the entire time, up until the end, at which point it should be melted. We've been able to achieve this by devoting 25-30% of the total water volume to solid water (commonly known as ice) and the remaining 70-75% to liquid water (commonly known as water).
4) We've used cool water, subtracted from our solid water + liquid water total, for pre-infusion but haven't yet measured the temperature. Using cool water is common, though folks like Lorenzo Perkins recommend high temperatures. Look towards the end of his article.
5) As always, coffee that is more finely ground is more readily extracted. It extracts faster, but also delays the brew time, so if you go too fine you'll probably overextract. Coffee that is more coarsely ground is less readily extracted. It extracts slower, but also quickens the brew time, so if you go too coarse you'll probably underextract. For this method, we've had success with a medium-fine grind: 14-15 on Baratza's Encore.
6) The top filter simply disperses the water, nothing more.
Posted Fri Jul 13, 2012, 12:42pm Subject: Re: DIY Aeropress Cold Drip Brewer for Under $30 - How To
primacoffee Said:
...
5) As always, coffee that is more finely ground is more readily extracted. It extracts faster, but also delays the brew time, so if you go too fine you'll probably overextract. Coffee that is more coarsely ground is less readily extracted. It extracts slower, but also quickens the brew time, so if you go too coarse you'll probably underextract. For this method, we've had success with a medium-fine grind: 14-15 on Baratza's Encore.
Have you actually achieved a technical overextraction with cold brewing? I find the flavor profile much fuller if using a fine grind - the contact at cold temperatures pretty much prevents extraction of the long-chain proteins and compounds that result in the traditional bitter flavors of overextraction.
Just asking, as I've tried coarse to near-turkish, and greatly prefer espresso grind if cold brewing (either overnight soaking or extremely long drip times). Problem is this fineness will clog up a melitta filter pretty well - that's why the AP filter works fairly well. I've even considered re-brewing (or recycling) the first bit produced because the majority of the fines come from the initial "settling" of the grounds into a moderately well-formed loose puck. Once the puck is organized, it seems to lock most of the fines in and keeps them out of the cup.
One kool thing to try: wet the grounds, then lightly "tamp" them wet, then set up your drip. I found that this greatly reduces fines but be careful not to tamp it too packed or you won't get decent percolation.
Does this method produce around 400g of coffee? What's the resulting strength? I suspect you won't technically overextracted until the strength gets north of 2.5% or so, but technically overextracting cold brewed coffee is pretty difficult.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
primacoffee Senior Member Joined: 19 May 2010 Posts: 36 Location: Louisville, KY Expertise: I live coffee
Espresso: Dalla Corte Evolution 2grp Grinder: Mazzer Mini Vac Pot: Yama Siphon Drip: V60, Chemex, Kone, Wave
Posted Fri Jul 13, 2012, 2:13pm Subject: Re: DIY Aeropress Cold Drip Brewer for Under $30 - How To
You're right in thinking that cold brewing forgives — or even favors! — a finer grind. As you said, it's difficult to achieve a bitter brew. We did notice, however, that there was a point at which the grind was so fine that
1] the water pooled at the top (the drip rate surpassed the drain rate, and this problem was made worse by the paper filter resting atop the grounds) and 2] the brew was unpleasantly strong and syrupy. Even at such a strength, though, it wasn't bitter. Not in the least.
And that is what is at risk when you go finer. But for some that's right up their alley.
Regrettably, we didn't record the actual yield. Your estimation is probably pretty close though!
A light tamp does sound intriguing... we'll have to give that a try! Thanks for the tip.
Just a guess based on my observations, but this is probably just an indication that you're approaching a correct extraction - above 2% strength on cold brew is exactly that - strong and syrupy, even properly extracted.
Your choices then would be to dilute to more normal strength (by adding ice would be my choice), or reduce your coffee amount. Incidentally, reducing the amount of coffee makes it easier for the percolation to happen and easier to reach correct extraction, and allow you to use finer grind. 45g is pretty darn deep in the AeroPress.
For decent cold brew, I'd aim for a strength of around 1.75% for the liquid, when you add ~1/3 in ice it will be more normal strength. To get there with ~500g of brew water (ice + water), you'll be looking at more like 37.5g of coffee. At 20% extraction, you'll be right around 1.75% strength or so and have around 425g of produced cold brewed coffee. The smaller depth also reduces the chance of pooling.
It's all fun and stuff - just a long time to wait for a cup of coffee! LOL
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
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