Kelham Senior Member Joined: 15 Apr 2009 Posts: 34 Location: Vancouver Expertise: I love coffee
Posted Sat Jun 23, 2012, 4:56pm Subject: iced aeropress blues
I've been using the iced aeropress recipe from here and keep getting a sour tasting coffee. Any idea why? I'm using a Costa Rica Tierra Fertil from 49th, although I've had the same problem with a Ethiopia Sidamo as well.
Posted Sat Jun 23, 2012, 9:16pm Subject: Re: iced aeropress blues
Kelham Said:
I've been using the iced aeropress recipe from here and keep getting a sour tasting coffee. Any idea why? I'm using a Costa Rica Tierra Fertil from 49th, although I've had the same problem with a Ethiopia Sidamo as well.
IMHO, it's a challenging recipe, and it's not surprising that your coffee tastes sour.
Mark's brewing ratio is way, way high. Putting it in English, that means he's using a very big dose of ground coffee paired with a very small amount of water. Despite the fact that he says, "it is quite easy to over-extract and deliver an excessively bitter brew," I think the opposite: it's actually quite easy to underextract, since there is so little water to do the extracting. Underextraction often leads to sour flavors, which is what you report. Underextraction also wastes coffee, since one has to dose higher than usual to achieve your desired coffee strength.
James Hoffmann recently made a similar point on his blog.
Nowadays many coffeegeeks are using lighter roasted coffee for iced methods. These coffees may really shine in the summertime with their crisp acidity. But they are harder to extract, making their acidity morph into sourness.
I think you will have more success using a lower dose of dry grounds and a higher amount of brew water.
IMHO, it's a challenging recipe, and it's not surprising that your coffee tastes sour.
Mark's brewing ratio is way, way high. Putting it in English, that means he's using a very big dose of ground coffee paired with a very small amount of water. Despite the fact that he says, "it is quite easy to over-extract and deliver an excessively bitter brew," I think the opposite: it's actually quite easy to underextract, since there is so little water to do the extracting. Underextraction often leads to sour flavors, which is what you report. Underextraction also wastes coffee, since one has to dose higher than usual to achieve your desired coffee strength.
James Hoffmann recently made a similar point on his blog.
Nowadays many coffeegeeks are using lighter roasted coffee for iced methods. These coffees may really shine in the summertime with their crisp acidity. But they are harder to extract, making their acidity morph into sourness.
I think you will have more success using a lower dose of dry grounds and a higher amount of brew water.
Technique: inverted Aeropress with paper filter, pressed over ice Coffee type: Intelligentsia Burundi Dry coffee dose: 25 grams Grind: pretty fine -- 12 on my Virtuoso -- YMMV Brew Water: 190 grams @ about 205F -- fits OK if the coffee isn't too fresh Stirring: a couple times, gently Steep Time: 3 min, then gently press Ice in Cup: 150 grams
Posted Sun Jun 24, 2012, 2:02pm Subject: Re: iced aeropress blues
I'd agree with Andys' comments - with high brew ratio and <3:00 contact time, with a moderate grind it's a high probability of underextracting. Back off a bit, don't sweat agitation, and bump the contact time up.
Finer is better, (JMHO) for the Aeropress with inverted use. I go for around 3:00 contact time - it's a good balance for me between hurrying and having the temperature drop or waiting for as long as a French Press.
Personally, I see no more than random variation in strength whether I stir vigorously the entire time, or just stir until the grounds are fully saturated and drop into the slurry (finer grind this happens around 1:30 or so, very coarse grind may be longer than 5 minutes - if you're seeing floating grounds when you're ready to press, try a finer grind). However, if the coffee blooms up and floats on top for more than 30 seconds and you haven't folded or agitated these grounds into the slurry - this is almost always a hallmark of something that will underextract (technically) but end up with weird flavor profile. I think what happens there is the grounds in contact with very hot water are also the smaller particles that get saturated right away and then can end up with some overextracted flavor bits, while the "high and dry" floating grounds don't contribute enough to the end strength.
Gentle pressing for the AeroPress results in much nicer clarity. This gets better if you re-vert the aeropress about 1 minute before you're ready to press, and then press gently. You'll engage the natural ability of the grounds to help act as a filter.
Andys' recipe is a great one to start with for iced coffee. 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
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