First, for those of you who read the title and have absolutely no idea what “sous vide” even means, don’t feel bad. Take this as a probably positive sign that you don’t spend any of your precious time watching modernist cooking Youtube channels. To save you that time and pain I’ll start by explaining what “sous vide” cooking is before we move onto how it can help you make amazing coffee. I promise this is only half as nerdy as it might sound.
“Sous vide” is nothing more than a French term for something vacuum packed. Cooking something “sous vide” is simple taking food (steak, fish, vegetables), vacuum-packing it, and then cooking it in hot water. This keeps all the food’s flavor exactly where it should be instead of allowing it to leak out into the cooking liquid.
While this used to be accomplished using a simple pot of boiling water, in modern times we’ve refine the method using something called an immersion circulator. An immersion circulator does two things. It A) heats water up to a very precise temperature and B) circulates the water around the container so that it’s temperature is uniform across. Want a pot of water heated to precisely 62.5 degrees and held their for two hours? An immersion circulator is what you’re looking for. This allows for the ability to very precisely and uniformly cook delicate objects. Many high end restaurants, for example, have taken to cooking their steaks sous vide. Cooking a steak in a precisely heated water bath allows for completely uniform cooking across the steak — no more grey bands of overcooked steak around your beautiful rare steak.
Immersion circulators truly used to be the provenance of high end restaurants given their exorbitant, $1000+ price tags. A new generation of companies have brought out simple, affordable at-home versions. The Anova device that we use, pictured above, can be had for <$150 on sale. These at-home immersion circulators open up tons of new possibilities for chefs, but more interestingly for our purposes, coffee lovers.
The reason for this is that coffee is a very complicated beverage. Its flavor is the product of hundreds of water-soluble compounds that find their way from bean to cup during the brewing process. The interesting thing about these compounds is they’re not created equal. Some taste quite bitter, some sweet. Some bring coffee a bright acidity, while others leave an acrid taste in your mouth. Brewing a great, balanced, cup of coffee is about controlling which compounds actually get extracted from the bean.
By far the main thing that determines which compounds get extracted is temperature. The coffee we know and love drinking (espresso or drip) is the product of very hot (85–100 degrees) water temperatures during extraction. This near-boiling water extracts almost all the bean’s varying chemicals, giving coffee its signature, complicated yet balanced flavor. On the other hand, you may have heard of people doing cold extractions of coffee (cold brew), by letting coffee grinds sit in water overnight. Because a lot of the bitter and acidic flavors are only extracted at hot temperatures a cold brew coffee is characteristically extremely smooth and easy-drinking but can be boring, lacking the punchy flavors of its hot older brother.
Since we’ve been preparing and drinking coffee the vast majority of it will have either been extracted hot (near boiling) or cold (near freezing) with very little in between. The immersion circulator helps us break down that dichotomy and explore some (in our opinion) very interesting possibilities in between the 24-hour/chilly cold brew and 3-minute/boiling hot drip methods.
The result of our experiments? One of our absolute favorite new ways to enjoy coffee. Our “warm brew” recipe makes cold-brew smoothness coffee but with all the complexities and punchy flavors of hot drip. Use a clean, washed Ethiopian, and you end up with something almost like a fruit tea extract. Use a nice nutty, chocolately Guatemalan coffee and you end up with what is indistinguishable from liquid, dark cocoa — like biting in to a really high quality 85% cocoa chocolate bar. For the espresso lovers this recipe yields an extremely condensed coffee that you could enjoy by itself or with milk in a latte, for the drip lovers simple water it down with hot or cold water for a more traditional coffee experience.
With that in mind, here’s the IMPCT Coffee guide to making delicious “warm brew” sous vide coffee. Remember, this is just a basic guide! Tweak and experiment to your heart’s content.
Things you’ll need:
- 125g Coffee. Good coffee! Go specialty. Because of the extraction process being somewhat hot and long coffee bean quality will be key. Harsh flavors, if present, will be over-emphasized. Maybe consider getting something that helps support poor families at origin while you’re at it (#shameless).
- 500g water. This is for another article, but the water you use matters. If your tap water is super soft go get a mineral water from the store for better extraction.
- Immersion circulator. We love our Anova. No they haven’t paid us to say this, although we’d be 100% open to that happening (call us).
- A jar. Big enough to hold the water and coffee (duh).
- A container or pot. Big enough to hold the… you get the point.
Quick note before we continue — this recipe can very easily be scaled up. We’ve done up to four jars at a time and I don’t doubt we could do more.
- Grind your coffee. Use a super coarse grind. We use our Bunn G1 cranked to the left. You’re probably safe with the coarsest grind your burr grinder has.
- Combine coffee and water in the jar. Stir. Stir again.
- Place the jar in your larger container/pot and attach the immersion circulator.
- Fill your container up with water until it’s just below the lid of your jar. We’ve tested more and less water and it doesn’t seem to matter much.
- Take out the jar of coffee temporarily and turn your immersion circulator on to 60–65 degrees. <60 will yield slightly smoother coffee, 65+more acidic coffee.
- Once the immersion ciculator has hit its target temperature, add your jar of coffee back.
- Allow the jar of coffee to brew for 1.5–2.5 hours. If you want a stronger concentrated brew do 2+.
- Stir once or twice during the process. This will allow the beans to fully rest in the brewing water and lead to better extraction.
All in all making our “warm brew” sous vide coffee is dead simple once you have an immersion circulator. I’d almost argue that this is one of the most foolproof ways to make exceptional coffee given how flexible the variables are. Add milk for a great latte or water for a juicy americano-style coffee.
Tried it? Like it? Hate it? Let us know down in the comments. If you want any advice on how to tweak your recipe for better performance I’ll try my best to help!