Posted Sun Aug 19, 2012, 1:13pm Subject: Re: Best Brewing Method For Iced Coffee
Mike250 Said:
what about half a gallon? I like this method a lot and want to experiment with it on a slightly bigger scale. What would be the potential problems that one might encounter?
Haven't had a chance to look - you're asking about flash-brewing a half-gallon of coffee, right?
Flash brewing is pretty simple - you brew double-strength coffee directly onto ice.
If you have a normal drip brewer that has 1/2 gallon capacity, you can do this by getting a normal recipe that works for you.
For drip methods, the extraction and strength relationship is based on the following:
E = S * (R-A), where E is extraction, S is strength, R is the water brew ratio, and A is absorption.
R = E/S + A, for a starting point I'd recommend targeting:
E = 19% (.19) S = 1.25% (.0125)
and most drip brewers can be estimated at A = 2
The answer for this is 17.2 brew ratio, or 17.2grams of water per gram of coffee.
That's the starting recipe - but you're setting up a flash brew, where the end result will be diluted by ice. So, you need to figure out the mass of the ice you're brewing into, and work the problem out for a stronger end strength (1.8% minimum, double strength will be about 2.5%) with the produced coffee amount minus the ice.
First up: R for 19% extraction and 2.5% strength is .19/.025 + 2 = 9.6; that's 9.6 grams of water per gram of coffee.
Next is the ice: maybe 900g? <shrug> If that's the case, you'll have a setup where your produced coffee is 900g less.
Coffee produced = brew water - (absorption * coffee)
From there, an important relationship shows up: (R - A). This is the yield ratio - how much coffee you produce for a given brew ratio and brew method as it relates to the coffee amount. We know that our target R is 9.6, and A = 2, so R-A = 7.6
If you want 1/2 gallon (about 1900g) of flash brewed coffee, but 900g of it is ice, you actually want only 1000g of coffee. 1000/7.6 = approximately 132g of coffee.
132 * 9.6 = about 1270g of brew water (under the capacity of the brewer, so good news there).
So, you'd measure out 132g of coffee, put 1270g of brew water in your brewer, and 900g of ice in the pot, and flash brew. In the end you'll have something moderately strong that will eventually dilute down to ~1.3% strength when all the ice is gone.
However, this is a lot of coffee to flash brew - adding more ice will dilute below normal consumption strength. Flash brew is more used for individual or a pair of servings.
This is different than warm-brewing where you use a lower temperature immersion and allow to cool before filtering and storing the concentrate cold - and adding it to ice when you need it.
I hope that makes sense - not sure if I'm answering your question properly.
------------------------------------------ ----------------------------------------- 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
Oh sure - you just need a way to filter or draw off the produced coffee.
One easy way would be to use something like a toddy or you can make your own filterbasket and use the big bunn filters (like the baskets you see at work).
Pick your strength, plug it into the equations with desired extraction - understanding that if you don't grind fine enough you may be underextracting - and use that brew ratio.
1900g brew water, 19% extraction 1.25% strength (basically normal strength) and if you're filtering with a filterbasket, A~2
R = 17.2, 1900/17.2 = 110g coffee.
Warm up the water to ~170°F, mix it with the coffee, allow to cool to about 110°F, then filter. You'll get a bit less than 1/2 gallon, but a bit more than 1.5liter.
Keep in mind if you do this, and THEN put it over ice you'll have really weak coffee. That's why most iced coffee is concentrate. If you're looking for heat-n-go coffee, this would be decent for a few days in the fridge, and re-heatable in microwave (avoid boiling).
------------------------------------------ ----------------------------------------- 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
Taste differences are highly subjective. You can try this on your own with a Mason Jar, and compare back to back the very next day.
Warm brew (to me) has more overall character. Cold brew, in my wife's description: "you gave me everything but the coffee taste!"
Cold brew has some parts of what we think of as "coffee" missing, and this uncovers an underlying "tea-like" quality to the taste. Some people feel that acidity is lower, and my crappy pH meter suggests this to some extent (approximately 5.5 on warm brew vs 5.9 for cold brewed, same Eight o clock 100% colombia coffee).
Both result in smooth overall taste. Both are mostly absent bitter flavors, although the cold brewed may be even slightly less bitter vs. warm brewed. Slightly more fruity-like flavor to the cold brewed. Both cool well and are pretty resistant to increased bitterness from longer term (30 minutes or more in a thermos) exposure to heat.
You'll get more coffee with the warm-brewed. You'll find this in a side-by-side:
I have a quart mason jar:
W = 750g C = 50g (R, Water Brew Ratio = 15)
Med-fine grind. You need something to filter out the coffee (a #4 filter basket works - it needs to be able to hold 55g of coffee expanded)
Cold-Brewed - combine the water and coffee, ensure all grounds are wetted, stick it in the fridge. Occasionally, peek in and make sure all grounds submerge and end up down at the bottom. You may stir it if you want, generally it won't matter. In about 12 hours, pour the contents into the filter and wait for it to drain.
Warm-brewed - combine 170°F water and coffee, stir well. Stir every once in a few minutes until all grounds sink. After about 12 minutes or so, pour the contents into the filter and wait for it to drain, then place into fridge.
Preparation:
Pour and heat up (I do it in a microwave, well short of boiling, target about 140°F). You can make a serving of both and see for yourself.
Good luck!
------------------------------------------ ----------------------------------------- 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
Mike250 Senior Member Joined: 24 Jan 2012 Posts: 36 Location: NZ Expertise: Just starting
Posted Mon Aug 20, 2012, 11:36am Subject: Re: Best Brewing Method For Iced Coffee
ok, I am going to get a good filter (do you recommend a plastic or a metal one?), burr grinder and a mason jar and try both and see how they come out. Are there any particular origins that you would recommend? I am thinking of trying a blend with those methods, but not sure what sort of coffees to mix and match
Posted Mon Aug 20, 2012, 1:40pm Subject: Re: Best Brewing Method For Iced Coffee
Mike250 Said:
ok, I am going to get a good filter (do you recommend a plastic or a metal one?), burr grinder and a mason jar and try both and see how they come out. Are there any particular origins that you would recommend? I am thinking of trying a blend with those methods, but not sure what sort of coffees to mix and match
The filter is not as critical - any paper filter will do. I've used a CCD (Clever Coffee Dripper) which has multiple use as a pourover, a steep/release brewer, or just a bulk filter like you'd use here. It uses the #4 melitta form (flattened cone filter) for which there are many choices if you want a metal filter. The #4 will hold about 450ml (450g) of liquid or coffee slurry, so 700-900g will have to be multiple pours (just pour it into the filter in halves).
I've also used the filter part of a BCM-4C, but that's only a #2 Melitta filter and upper range of capacity is about 55g of wet coffee.
Or, you could use a chemex.
Wherever you are (NZ?) I'm not sure what coffees you have available, but I'd recommend a ubiquitous but decent and low cost whole bean arabica coffee to dial in your technique. By ubiquitous, even if weeks old since roasting, decent storebought coffee is a good test - if you can make that taste "pretty good" and "better than anyone else has been able to do", then when you do same techniques on $15/lb coffee you won't have to go through too many failures.
I use readily available Eight o Clock 100% colombia - it's not OUTSTANDING, but it ain't too bad, and it's consistently roasted bag-after-bag and month after month, 100% arabica, available pretty much anywhere in the country, and cheap. I also have used Dunkin Donuts medium roast (another lower cost consistently roasted coffee). For dialing in a brewing technique, it's easier if you pick a decent and cheap coffee - it allows you to not worry about ruining that beautiful roast or wasting a half lb or more figuring things out.
------------------------------------------ ----------------------------------------- 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
Not exactly sure what you mean by "double filtration" but the way coffee filtering works (as far as I've been able to deduce) is this:
-The coffee grounds settle against the "filter" aka "filtration barrier". Initially, whatever the rating of the filter is lets some undissolved solids through into the cup. Most paper filters will let <40micron particles through. Metal filters maybe <200microns.
-Once the grounds settle against the filter, the depth of the grounds and the bed of grounds provides a much more efficient "filter" and actually does the majority of filtering as we think about it. A large majority of absorbed cafestol and kahweol (lipid/diterpenes) gets absorbed by the grounds bed and not necessarily the filter. Except for the first portion, if the filter is metal or nylon, before the grounds settle into a nice bed.
-You can disturb this filtering by stirring, but there is still a decent filtering layer due to particles stuck in the filtration barrier.
You may verify this yourself:
Make a press pot of coffee. It will have a bunch of dregs in the produced coffee (Press Pot/French Press coffee always does if made traditionally).
-Pour the produced coffee (only) into a cone filter. If you are lucky and it doesn't clog, then the result will be partially clarified but much cloudier than a normal drip.
-IF you pour this again through the same filter, it might improve A LITTLE.
-If you pour this through a new filter, you'll find little change. This is because a new filter passes much of what's already passed.
Make another press pot of coffee.
-This time - don't press filter it, stir the slurry up when the steep is done and pour all of the slurry into the cone filter. The result will look darn close to auto drip coffee.
You can also take the stuff and re-pour it into the already wet grounds bed - and the clarity will be nearly indistinguishable from auto drip.
So "double filtering" if using just a paper filter won't do much. "double filtering" through a grounds bed - that should improve the clarity.
Then, if you're really ambitious, you can redo all of this using an AeroPress. If you have an AeroPress, you can let the grounds settle against the filtration barrier and gently press - the bed of grounds will do the majority of filtering, even if you use a metal disc filter rated at 150microns.
------------------------------------------ ----------------------------------------- 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
Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post
Forum Rules: No profanity, illegal acts or personal attacks will be tolerated in these discussion boards. No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum. No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum. Who Can Read The Forum? Anyone can read posts in these discussion boards. Who Can Post New Topics? Any registered CoffeeGeek member can post new topics. Who Can Post Replies? Any registered CoffeeGeek member can post replies. Can Photos be posted? Anyone can post photos in their new topics or replies. Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts. Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.
= No New Posts since last visit 