Experiments: Cafe Solo/V60 Cold Brew Hybrid

October 1, 2010

All the gear you need for experimental cold brew.

This isn’t going to be a very good post. In fact, I can tell you right now it’s going to be a terrible post. Absolutely horrific. Undeniably shudder inducing.

And why’s that? Because I performed this experiment on August 17th, and I’m writing this on October 1st. Whoops. WordPress got broken, and I couldn’t get it fixed — it didn’t want me to upload photos, and that’s the whole dang basis of this dang here gosh darn blog post. Pretty pictures!

But maybe we’ll figure this all out. There’s a chance I might be able to. I can reconstruct these events using the photos I took. Let’s start out first with some theory.

This whole experiment owes it’s genesis to Jesse Kahn, currently of the unfortunately named World Bean (No apologies! It’s cheesy!).

The coffee, coarsely ground, waiting for the water to heat.

One dark eve, sipping on some coffee, Mr. Kahn and I were discussing cold brew methods, and my dislike of them. He then mentioned the fact that a hot bloom on a cold brew might bring out more of the acidity of the coffee, since a lot of those tones turn up in the first forty seconds or so of brewing.

So I stoled that idear. WELL, I told him I was going to steal it. And he seemed okay with that. But I had an even better idea. Why not hot bloom in a Cafe Solo, and then filter it in a V60? It’ll already be pre-filtered of large particles, and there won’t be excess agitation when filtering it through paper.

So here we go!

I wanted to use the Golden Ratio, so we went straight 60 grams and one liter of water. Pretty clever, right? I went for a fairly coarse grind on this sucker. I figured that if it was a twenty-four hour brew time, I could afford a Toddy style coarse grind. This might have been the downfall for this first experiment.

Zeroed out.

And we’re just waiting for that water to hit temp. The whole goal was to hit it with a hot bloom, right? So of course the water has to be hot! I used my Hario Buono kettle to bloom the coffee, and had a liter of cold, filtered water standing by to immediately drown the bloom and try and cool it down. We didn’t want this to be a hot brew. It’s a cold brew, at heart. Which means cold water. Duh.

Time to start that bloom! I think the water temperature was around 200 Fahrenheit, but who really knows anymore? It could have been as high as 204. Sheesh. this article really is sloppy.

Stirring is verboden when it comes to Toddy style, but this ain’t no Toddy. Agitation is the key to extraction with immersion methods, and I wanted to treat this like a hot brew since it was a hot bloom. I think I waited a minute?

No specific bloom weight in mind, just trying to get an even coverage.

Here’s the pseudo-science that we’re basing this off of: coffee has a sort of plateau curve when it comes to extraction. At a certain point, it’s going to level off. Agitation (i.e. stirring) causes a new curve to shoot up off the extraction curve that it was currently on. Make sense? In our (my) attempt to get a solid extraction curve going, we (I) used agitation to promote more extraction!

Now this is pseudoscience for a few reasons. I really have no data that backs this up besides a graph I saw in a Scott Rao book, and my own danged palate. And this is touching on another thing I want to write about in the future: the science and pseudoscience behind coffee brewing. As much as strict science can aid coffee brewing, not everyone can afford a refractometer to measure your extraction levels with ExtractMojo. So you have to use the tools God gave you, and a basic understanding of the underlying scientific principle, even if you can scientifically measure it’s effect. ANYWAY.

Looks like I settled on 159 for the bloom weight. It wasn’t very good coverage, so not only did the stir promote extraction, it also promoted even saturation of all coffee grounds.

Let’s add some water, shall we?

Starting the cold water pour.
Carafe filling up.
One liter, up to the top.

And then it was time for the cold water coverage. It was pretty hard keeping my crappy scale on the right weight, because of the stupid enormous weight and it’s shitty internal whatevers.

A really glorious bloom reaction, some sort of weird half-halted bloom occurring as the cold water mixes in with the hot bloom, truly stunning to watch.

Holy fucking shit was that awesome looking. The bloom was still reacting, even in the cold water. It was super angelic, and beautiful, and man was it appetizing. No idea why.

And for twenty-four hours, or relative thereabouts, it brews.

Then it goes into the fridge in between grapes, English muffins, and some red pop.

Time to filter this sucker.

Twenty four hours later, it was time to get busy.

Rinsing the filter, of course, with cold water. Almost used hot.
Beginning to pour into the filter. Not sure what to expect.
Oh, it’s filling up fast. Annnnd it’s draining sort of slow.

My ingenious plan of using the Cafe Solo as a pre-filter didn’t go as well as I thought it would. It still was a very slow drain due to the particulate suspended in the brew. But I knew it would be worth it, if I just could wait it out.

But man it was a long wait. A series of pouring, waiting, pouring, waiting, trying to be patient, pouring more, waiting more, and sheesh. During round two (not photographed), I tried stirring it up with a chopstick a the very end, and poked a dang hole in the bottom of the filter. Whoops.


Some more shots of it dripping. Yeah, I don’t know.

The finished product. Pretty tasty, but not the best, if I can remember correctly.

And there we have it. It was a bit lacking in brew strength and extraction if I can remember. Just a little too light on the tongue and slightly sour. Kenya Thiriku, by the way. Round two saw me use 80g of coffee and an extra stir after I added all the cold water. It saw much better results.

Sweet, fruity, winey — it was very reminiscent of what the coffee yielded in a hot brew. And chuggable. You could down a glass really easily. Still, the best cold coffee I’ve ever had was just an extra cooled Chemex of an Ethiopia Yirgacheffe. But that usualyl doesn’t stay good after a few hours. You’ve got a peak window to drink that, and this cold brew seemed to be the prescribed method.

So Jesse Kahn: thanks. And instead of trying a control brew with no hot bloom to compare, I’m just going to assume it wouldn’t be as good, because it’s October 1st today, and cold as shit outside.

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{ 1 trackback }

Cold Brew, Hot Bloom « brewtasterepeat.
10.05.10 at 3:56 pm

{ 4 comments… read them below or add one }

1 John Letoto 10.01.10 at 1:38 pm

Hrm. Interesting. Makes me feel a little more normal for brewing a V60 on a turntable :)

2 Jesse Kahn 10.01.10 at 2:18 pm

Your name’s cheesy! You are! I’ll Intelligentsia you! and so on and so forth.

Nice write up, my friend. I’ve been working on this method as well, and have found some solid results adding half of the cold water weight as ice right on top of the hot bloom…

3 Collin 10.05.10 at 3:58 pm

Started to write a comment detailing my experiences with this method but it kept getting longer and longer. Ended up turning it into a blog post which can be found here: http://brewtasterepeat.wordpress.com/2010/10/05/cold-brew-hot-bloom/

4 Richard 12.07.10 at 4:39 pm

woow in random googling, i ran into a post byy john letoto :p

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