As I discussed at Cocktail Camp a few weeks ago, one of my interests lately has been finding ways to use coffee in cocktails without having to brew on demand. Making coffee bitters is one solution. Clarifying coffee is another. This isn’t a perfected process yet but the results are interesting and I’m hoping this post will encourage others to try it out.
My goal with this was to create a cold coffee with a shelf life of at least a few days that could be kept in the refrigerator and used when needed. The easiest method would be to use a Toddy brewer to make a cold-brewed coffee concentrate. This certainly works but cold-brewing and hot-brewing have different flavor profiles. Cold-brewing pulls out dark, chocolaty, nutty flavors. Hot-brewing captures more of the acidity and fruit notes found in many great coffees. For making iced coffee I much prefer the Japanese hot-brewing method popularized by Counter Culture’s Peter Giuliano to Toddy and other cold methods. Hot-brewing produces more the flavor I was looking for.
That’s where gel clarification comes in. The basic idea is to create a web of gelatin to capture the oils and solids in a liquid so that only water soluble flavors remain in the final concentrate. It’s like making a consommé except that you’re adding gelatin to liquid instead of utilizing the gelatin that occurs naturally in meat. Harold McGee explained how the process can be used for all kinds of liquids in The New York Times a few years ago. Soon after World Barista Champion James Hoffmann applied it to coffee.
I’ve run two different coffees through the process so far: Stumptown’s Ecuador Quilanga and Counter Culture’s Sidama Michicha, a natural coffee from Ethiopia. I was really happy with the results. While I wouldn’t expect any cold coffee to match the aromatic complexity of a fresh hot cup, the two were distinctly different in flavor, with the fruit notes of the Michicha standing out surprisingly well. Cocktail ideas immediately started presenting themselves. How about a flight of drinks mixing neutral vodka and three different clarified coffees? Could be fascinating.
I tried several methods of clarification and none so far none have worked better than the one James originally posted. I’ll explain that briefly below but please visit his site for a full explanation. The good news is it’s easy to do. The bad news is it will take some time, about three days total (though I’ll discuss a faster alternative below), and space in a freezer and refrigerator. This will rule out its use on many professional cocktail menus, but it could still be something fun to keep behind the bar or for home experimentation.
Here’s the method I followed:
Step 1: Brew coffee and filter through paper. I brew at home in an Eva Solo which I then had to filter through an Aeropress. Ideally one would just use a pour-over or Chemex instead of this roundabout method.
Step 2: Bloom 8 grams leaf gelatin in water, then dissolve and whisk into 500 grams of the coffee (slightly more than a liter by volume).
Step 3: Allow to set for a few hours in a refrigerator.
Step 4: Transfer to a freezer and freeze into a solid block.
Step 5: Lay block in muslin, place in a colander, and suspend the colander in a bowl. Put everything back in the refrigerator until the ice thaws. I sped the melting by breaking the block into a few pieces, increasing its surface area as in the photo below.
Over two days the ice slowly melted through the muslin and colander, taking water soluble flavors with it. A thin layer of coffee gel was all that was left behind.
In the bowl was the clarified coffee. Obviously some coffee is lost in the clarification. I went from 500 grams down to 381 grams. As James notes you can increase the clarity even more by repeating the process, but you’ll lose more liquid too. I stopped at one run through since I’m going for clarity not complete lack of color. For comparison’s sake, here’s the clarified coffee next to a Toddy brew and coffee run through a paper filter.
After all that waiting I was ready for a drink. Here’s one I’ve been experimenting with and calling the Dimmitude cocktail, inspired by the traditional caffé corretto (espresso and grappa). I may play with this a bit more when I’ve made my next batch of clarified coffee but it was working well with the Michicha:
1.5 oz grappa
1 oz clarified natural coffee
1 oz Dimmi
Stir over ice and strain into a cocktail glass.
Dimmi is a light, floral, herbal liqueur blended with a touch of grappa. Natural coffees like the Michicha are dried with the cherry still on the bean, sometimes resulting in dramatic fruit or berry notes. Combining these with quality grappa makes a unique, lightly fruity cocktail with a gentle coffee bitterness. (If you saw my presentation at Cocktail Camp I made this drink with vodka there. Grappa is a better choice; I’m currently using Uva Viva di Poli.)
Is clarifying coffee for cocktails worth the effort? Probably not for regular use, given how much time and space it consumes. Using good iced coffee is more practical. However it is fun to work with and the clarified coffee looks great in a stirred drink, plus it seems to last for at least a few days if refrigerated.
Agar method: There is a faster way to clarify liquids using agar in place of gelatin. Agar sets at a higher temperature than gelatin, so one can follow a similar process to that above but melt the ice at room temperature instead of in a refrigerator. Indeed one can omit the freezing step altogether, gently squeezing agar curds through muslin. Obviously either of these methods will require less time than gelatin filtration.
The downside to using agar is that it also hydrates at a higher temperature. So while gelatin will work just fine in freshly brewed hot coffee, agar works best in boiling liquid. Unfortunately boiling brewed coffee will cause overextraction, resulting in a bitter cup.
To get around this one could theoretically boil agar in, say, 100 grams of water, then mix that into 400 grams of coffee brewed to a correspondingly higher strength and proceed with the freeze-thaw approach. Of the agar clarifications I tried that method came closest to the results with gelatin, however it was not quite as clear and the taste was a little off. It was close though and worth another try. (Using the fastest method of just squeezing the agar gel through muslin may leave some residual agar in the liquid. This is another time when an Aeropress comes in very handy for filtering it out.)
Coffee clarification is something I’m still experimenting with and I would love to hear from anyone else who tries it or incorporates it into cocktails. Perfecting an agar method would be ideal and I’m also curious to see what other drinks people create, either with coffee or with other clarified liquids.
[As with so many of these kinds of posts, thanks to David Barzelay for advice on using these different methods.]