Interesting...

Right now I'm just finishing up the Starbucks Iced Coffee blend. I also read that a 24-hour room temperature brew is what Intelli recommends... ?

I wonder if anybody has experimented with all the timing and temperature for cold brews. For example, was there a difference between brewing the coffee in the fridge or room temp?

I've tried brewing the coffee for 12 hours and 16 hours. So far, I don't really notice a distinct difference...

The "caramel" flavor that the Iced Coffee blend promises, is minimal at best. I'm using Ghirardeli caramel sauce to sweeten up the iced coffee, and it's pretty good. I had like six cups of it yesterday in one sitting, and I was having such a caffeine rush, I had trouble breathing... definitely gonna have to watch my intake.

I have used a toddy frequently over the years, although the tub broke a while back, and haven't got around to getting a new one. Plus I was blowing through a lot of coffee. I am surprised actually that more HB'ers don't use either the toddy or the filtron cold brewers as they are both capable of producing good iced coffee. I have more experience with Toddy, so here is my method as close as I can remember!!
I use 1 pound of medium coarse grind (ground to the 8th mark on our ditting kr1203 properly calibrated grinder at our store), sorry I don't know what the overall grind particle size is. This grind as I remember was slightly finer than what toddy recommends. I add some of the grounds and slowly add the cold filtered water and then add more grounds and top it off with the rest of the water (total water = about 65 fl ounces) making sure to wet all the grounds evenly as possible all the way through. I then let it steep (covered) at room temp and for approximately 20-24 hours before pulling the stopper and letting it drain into the carafe. I haven't experimented much with using the concentrate to make hot coffee, but just iced coffee, I use a ratio of about 1 part coffee to 1 part water and pour over ice. I don't keep the concentrate in the fridge for more than a week and replace the filter every couple three months. Also, I thoroughly rinse the filters after each use with hot water. I typically use a coffee with a lot of intensity in the cup. Heavy on the fruit and wine like, berry notes and those with a bright acidity and a big full body i.e. Kenya AA's. I also enjoy many Ethiopia Sidamo dry processed coffees as the wild, spicy, and fermented character comes though well using a toddy. I have found the longer steep time to be necessary to produce a flavorable concentrate. That's pretty much it! P.S. don't stir the grounds at all while they are in the tub

Psyd wrote:A friend of mine has gone a bit DIY with the concept:

This is brilliant! And I agree with the previous posters -- the reason to go with the Hario is simply design. The components are nice and it looks great on the counter. Given how much the aesthetics of espresso machines factors into reviews I figured this is not a completely alien to this community

Has anyone tried the Oji cold brew tower? They had one in a cafe in Melbourne, Australia that I visited and it produced a delicious, fairly viscous, espresso-style drink.

Hey all. I've experimented with extraction measurements (dehydration method) and cold brewed coffee. Saw this thread and thought I'd throw my $0.02 into the mix.

What I've found is the strength goes up but the extraction goes down with increasing brew ratio. Three examples of measured brews were a 15%, a 21% and a 35% brew ratio, fairly fine grind (equivalent Ditting 6) with a 24 hour contact time in the fridge. After contact time, the brews were Aeropressed to separate the grounds, then grounds dried in a 215°F oven to determine extraction. I also have done multiple extraction measurements where I fully evaporate the produced beverage to confirm transfer of all solids, and duplicated the 21% brew ratio and evaporated the results to re-confirm that the dried grounds method is still sound.

The results were:

15% brew ratio, 17.2% extraction, 3.6% strength.
21% brew ratio, 16.4% extraction, 5.1% strength.
35% brew ratio, 14% extraction, 10% strength.

I did drink the results too. The coffee was self-roasted Panama to Full City, nice slightly fruity (apple) moderate brightness, some malt and nutty tones, with a slight nutmeg finish and medium body - when brewed normal temperature.

When brewed cold, the fruit and any potential brightness was completely absent. The malty flavors and nutshell essence became more evident with the higher brew ratio. 15% brew ratio had very muted brightness, but the 35% underextracted brew was somewhat pungent, sour (definitely not bitter) with a very 'off' flavor profile and creeping tones of molasses and pecan. Interesting was that the 35% brew ratio SPENT GROUNDS were very nicely fragrant after dehydration - meaning it still had stuff in it that just wasn't extracted.

The best of all of these was by far the 15% brew ratio. Cold brewing doesn't seem to be able to exceed much more than 17% extraction. The produced concentrate is about double strength of normal coffee and works well for coffee drinks.

I since went on with the 15% brew ratio method, and brewed six or seven different coffees that I had on hand, from *$s Pike Place, a Guat I had (Caribou IIRC), even Dunkin' Donuts and some Eight o Clock Columbia. These SHOULD have tasted significantly different, but the varietal character was pretty much wiped out (or never extracted) by cold brewing it, and they all became very similar in flavor profile, almost to the point of being indistinguishable.

As always with coffee, YMMV - just sharing what I've found. I've finished looking at cold brewing and figure I spend way too much time roasting, perfecting coffee brewing, and tasting coffee to leave chunks of the varietal character behind when I have so many other choices in methods to brew excellent coffee. Cold brewing is a great way to take something like a blueberry-like experience of an Ethiopia Harar or Yirg - and end up with something that tastes like very nicely brewed but low complexity Colombia.

BTW - if I need concentrated coffee for some recipe, I produce a nice 5% strength coffee using 22.5g of coffee and 125g of water brewed in an inverted Aeropress with 1-to 1 1/2 minute contact time and 200-205°F water. I just put it in a sealed container and it goes into the fridge as is. The varietal character is all there, and is WONDERFUL on ice cream, or used in a diluted iced coffee drink. It appears to store as well as cold brewed coffee but if kept sealed in the fridge, will still contain a ton of the varietal character even several days later (which will NOT be present in the cold brewed coffee). I can also use it as a pre-brewed "semi-instant" by making it the night before, diluting with the proper amount of hot water the next morning. I've stored the hot brewed concentrate right next to the cold brew, and have played the "blind taste test" game with several people - they can hardly believe they are the same coffee. One is smooth and nutty and fairly nondistinct, the other has all kinds of flavor tones and character - and you can guess which one is which.

George and Jenny Howell just put out a video on Iced coffee with recipe

Awesome series of links, btw (the G. Howell primers on brewing, coffee storage, etc.). Highly recommended.

Please note that the "flash brewing" technique basically creates hot brewed double strength coffee that when added to correct amount of ice creates the best of both worlds (the brightness and character of a hot brewed coffee but net result is iced coffee).

It is NOT cold brewed coffee.

However, it IS a great recipe for iced coffee.

Kevin Knox in "Coffee Basics" describes similar technique (doubling the brew ratio for a press pot, and icing the result for iced coffee) in his book. The resulting beverage is around 2.5% to 3+% strength BEFORE icing.

Netphilosopher wrote:Hey all. I've experimented with extraction measurements (dehydration method) and cold brewed coffee. Saw this thread and thought I'd throw my $0.02 into the mix.

What I've found is the strength goes up but the extraction goes down with increasing brew ratio. Three examples of measured brews were a 15%, a 21% and a 35% brew ratio, fairly fine grind (equivalent Ditting 6) with a 24 hour contact time in the fridge. After contact time, the brews were Aeropressed to separate the grounds, then grounds dried in a 215°F oven to determine extraction. I also have done multiple extraction measurements where I fully evaporate the produced beverage to confirm transfer of all solids, and duplicated the 21% brew ratio and evaporated the results to re-confirm that the dried grounds method is still sound.

The results were:

15% brew ratio, 17.2% extraction, 3.6% strength.
21% brew ratio, 16.4% extraction, 5.1% strength.
35% brew ratio, 14% extraction, 10% strength.

I did drink the results too. The coffee was self-roasted Panama to Full City, nice slightly fruity (apple) moderate brightness, some malt and nutty tones, with a slight nutmeg finish and medium body - when brewed normal temperature.

When brewed cold, the fruit and any potential brightness was completely absent. The malty flavors and nutshell essence became more evident with the higher brew ratio. 15% brew ratio had very muted brightness, but the 35% underextracted brew was somewhat pungent, sour (definitely not bitter) with a very 'off' flavor profile and creeping tones of molasses and pecan. Interesting was that the 35% brew ratio SPENT GROUNDS were very nicely fragrant after dehydration - meaning it still had stuff in it that just wasn't extracted.

The best of all of these was by far the 15% brew ratio. Cold brewing doesn't seem to be able to exceed much more than 17% extraction. The produced concentrate is about double strength of normal coffee and works well for coffee drinks.

I since went on with the 15% brew ratio method, and brewed six or seven different coffees that I had on hand, from *$s Pike Place, a Guat I had (Caribou IIRC), even Dunkin' Donuts and some Eight o Clock Columbia. These SHOULD have tasted significantly different, but the varietal character was pretty much wiped out (or never extracted) by cold brewing it, and they all became very similar in flavor profile, almost to the point of being indistinguishable.

As always with coffee, YMMV - just sharing what I've found. I've finished looking at cold brewing and figure I spend way too much time roasting, perfecting coffee brewing, and tasting coffee to leave chunks of the varietal character behind when I have so many other choices in methods to brew excellent coffee. Cold brewing is a great way to take something like a blueberry-like experience of an Ethiopia Harar or Yirg - and end up with something that tastes like very nicely brewed but low complexity Colombia.

BTW - if I need concentrated coffee for some recipe, I produce a nice 5% strength coffee using 22.5g of coffee and 125g of water brewed in an inverted Aeropress with 1-to 1 1/2 minute contact time and 200-205°F water. I just put it in a sealed container and it goes into the fridge as is. The varietal character is all there, and is WONDERFUL on ice cream, or used in a diluted iced coffee drink. It appears to store as well as cold brewed coffee but if kept sealed in the fridge, will still contain a ton of the varietal character even several days later (which will NOT be present in the cold brewed coffee). I can also use it as a pre-brewed "semi-instant" by making it the night before, diluting with the proper amount of hot water the next morning. I've stored the hot brewed concentrate right next to the cold brew, and have played the "blind taste test" game with several people - they can hardly believe they are the same coffee. One is smooth and nutty and fairly nondistinct, the other has all kinds of flavor tones and character - and you can guess which one is which.

Very interesting. Thanks for the informative post.

I understand you've ran countless tests to compare and contrast the cold brewing process.

Have you ever experimented with cold brewing and room temp brewing? People seem to be pretty conflicted with these methods. Some say you should add cold water and then just let it sit on the counter for a day. Some say to add room temp water and toss it in the fridge, etc etc.

Do you think there's much variation between these two?

I've tried adding cold water and tossing the grinds in the fridge for a 100% cold brewing process, but I've also tried adding room temp water and then tossing the grinds in the fridge... just a rough estimation, the process where I added room temp water actually produced a minor bloom (crema-like surface) in the coffee press. The process where I used cold water, throughout, it didn't produce any bloom. Also, the version where I added room temp water tasted noticeably more acidic.

Netphilosopher wrote:Awesome series of links, btw (the G. Howell primers on brewing, coffee storage, etc.). Highly recommended.

Please note that the "flash brewing" technique basically creates hot brewed double strength coffee that when added to correct amount of ice creates the best of both worlds (the brightness and character of a hot brewed coffee but net result is iced coffee).

It is NOT cold brewed coffee.

However, it IS a great recipe for iced coffee.

Kevin Knox in "Coffee Basics" describes similar technique (doubling the brew ratio for a press pot, and icing the result for iced coffee) in his book. The resulting beverage is around 2.5% to 3+% strength BEFORE icing.

"Flash" brewing definitely sounds marketable and appealing, but honestly, I think it's a lot more trouble than necessary.

I doubt there's any noticeable difference between using that setup and just hot-brewing some coffee and tossing in ice.

Before cold brewing, I used to just pull a shot of espresso, add ice and milk for an iced latte. I've also tossed a warm latte into the fridge to drink later, and it also tasted just about identical. It's very hard to taste any staleness if you're adding milk, which literally absorbs everything.

For the most part, I think it's fine. People bring up "staleness" a lot, but I doubt 99% of coffee drinkers have the palette to even notice it, especially when most people add milk to the drink.

I like to drink cold brewed coffee without milk, so I can taste the staleness after a few days in the fridge, but I'll just add more coffee and it won't be a big deal.

bigbad wrote:Very interesting. Thanks for the informative post.

I understand you've ran countless tests to compare and contrast the cold brewing process.

Have you ever experimented with cold brewing and room temp brewing? People seem to be pretty conflicted with these methods. Some say you should add cold water and then just let it sit on the counter for a day. Some say to add room temp water and toss it in the fridge, etc etc.

Do you think there's much variation between these two?

I've tried adding cold water and tossing the grinds in the fridge for a 100% cold brewing process, but I've also tried adding room temp water and then tossing the grinds in the fridge... just a rough estimation, the process where I added room temp water actually produced a minor bloom (crema-like surface) in the coffee press. The process where I used cold water, throughout, it didn't produce any bloom. Also, the version where I added room temp water tasted noticeably more acidic.

Well, not surprisingly, I have experimented with this. Very little taste difference with room temperature vs. cold temperature STEEPING. Maybe just a touch more acidity but still very muted varietal character with room temperature steeping.

There was no difference in my opinion between cold water (about 45°F) charging and room temperature (about 75°F) charging, independent of steeping temperature. (charging means the water going into the dry grounds).

The room-temperature steeping looks uglier, though. After 12 hours, I was afraid it maybe had started to ferment, but I suspect this was just a bit more off-gassing (bloom).

As far as checking extraction, if there is a difference it is in the half % or less range, and would require more than a run or two to figure out, and probably double the volume for more accuracy. 15% brew ratio still seems to be about right, losing more character and getting more nutty as the brew ratio goes up from there. I'm fairly certain that the difference between a calculated 17.2% and 17.7% extraction is nil.

I haven't identified the real inflection point range, but I think the charging temperature above 180°F is key to extracting at least SOME of the varietal character and acidity. At some point, it becomes moot - cold brewing (brewing with <100°F water) underextracts. There's some portions of the coffee you just can't extract without higher temperature water. Good news is you'll probably never overextract using this method, and in a world where overextracted swill is ubiquitous and dark roasted heavy roast coffee seems to be the specialty shop norm, this can be a very eye-opening and refreshing change.


On a side note, I did have a decent experience using Ethiopia Shakiso and cold brewing - the only cold brew where I got a faint hint of fruit character. However, it was a mere shadow of this coffee properly brewed, which can have beautiful merlot winey character and nice bright snappy citrus notes with an overtone of blackberry or blueberry. Cold brewed it has a hint - just a whisp - of blueberry... and that's about it. It tasted great and was distinguishable from other cold brewed coffee, true, but it certainly was a waste of the full potential of this single-origin.

Of course, as a friend of mine says, there's no wrong answers in coffee - just what tastes good.