Hello sous vide fam, and welcome to a particularly caffeinated instalment of Will It Sous Vide?, a column where I make whatever you want me to with my immersion circulator.
Photos by Claire Lower and Chris Vasquez.
Given the fact that my coffee palate is, in a word, "basic," I consulted someone with more experience. Though I like to give him grief for using terms like "third wave coffee" and attending latte art throw downs, there is no denying that the man (aka Chris of Seven Virtues) knows his beans.
Not only was Chris kind enough to bring me some really good coffee (an Ethiopian bean with nice "peach, mixed berry, and juniper" notes), he even ground it using a fancy burr grinder. (For you nerds out there: He used a Mahlkonig Kenia.) He ground the beans using two different settings: that used for auto-drip (which is setting #10 on the Kenia) and that used for French press (#18).
Auto-drip grounds, which are the finer of the two.
French press grounds.
Since the ideal temperature range for coffee extraction is 90°C to 96°C, we decided to brew four different samples:
- 18.5 grams of coffee ground for auto-drip, extracted at 96°C in 300mL of water for four minutes.
- 18.5 grams of coffee ground for auto-drip, extracted at 90°C in 300mL of water for four minutes.
- 18.5 grams of coffee ground for French press, extracted at 96°C in 300mL of water for four minutes.
- 18.5 grams of coffee ground for French press, extracted at 90°C in 300mL of water for four minutes.
However, before the grounds could be added to the water, we had to get it up to temperature. The easiest way to do this is to measure out your water into freezer bags and set them in the bath when you first turn on your circulator, that way your brewing water will arrive at your target temperature at the same time as your water bath.
It is very important that you use actual freezer bags, not a sandwich bag like the one you see in the above photo. (I wasn't thinking and grabbed the wrong bag at first and that thing sprung a leak and made me sad.) Once your water is ready, add in the grounds, put the bag back in the bath, and set a timer for four minutes. Why four minutes? Four minutes is the brewing time recommended when making French press coffee and, since that method is fairly similar to sous vide, we went with that.
Then it was tasting time. We cut a tiny hole in the corner of the bags and -- using oven mitts, because that ish was hot -- poured the coffee through a fine mesh strainer into cups.
I may of may not have made a mess with one of the samples.
We both tasted the coffees, with Chris using a spoon and me taking sips like a normal human.
It's not soup, bro.
These were our thoughts (you will notice that one set of thoughts are slightly more helpful than the other):
Auto-drip grind, extracted at 96°C for four minutes:
Claire: "I don't like that. It tastes like coffee that comes out of a pot that has been sitting on the warmer for too long."
Chris: "This tastes over-extracted. It's bitter, and you don't get those nice berry notes like you should."
French press grind, extracted at 96°C for four minutes:
Claire: "I like this!"
Chris: "This one is much more balanced, and you get more clarity with the flavours. You can actually taste the fruit notes. This surpasses what I would expect from a French press. I would drink this." [Claire's note: "I would drink this" is much higher praise than one would think. There are a lot of things Chris won't drink that I would.]
French press grind, extracted at 90°C for four minutes:
Claire: "I like this too!"
Chris: "This one is ok, but slightly blander than the 96-degree sample. It lacks some of those berry notes and some of the sweetness."
Auto-drip grind, extracted at 90°C for four minutes:
Claire: "Still gross."
Chris: "Yeah, this is the same [as the 96-degree sample], but cooler."
And now it's time to ask our favourite question: Will Coffee Sous Vide?
The answer: Yes, and it makes for a pretty good cuppa. More interestingly though (to me, at least) was how the experiment demonstrated the importance of grind-size, something I had considered to be a little too precious before. A four-minute extraction of the French press-ground sample at 96°C yielded a beautiful, complex-tasting cup of coffee with all of those promised flavours present. The auto-drip sample however was so bad, that even I rejected it as "just bad coffee."
That being said, it's certainly not the most practical way to brew coffee; it's a bit clumsy and it requires about half an hour of wait time while the bath and brewing water come up to temperature. However -- unlike a certain coffee brewing system that rhymes with "pharaoh chess" -- it would be pretty easy to scale up. You could brew a big bag of perfectly temperature-controlled coffee, strain that whole thing in a big pitcher, and serve. Though Chris won't be replacing his pour overs with sous vide coffee, he couldn't deny that it made a good cup (better than a French press in his not-so-humble opinion). Given his high standards, I consider this a sous vide victory.