July 24, 2015

Quick cold brew: how to make one in just 60 seconds


Extraction is a word that sums up every coffee-making process in existence You add solid grounds into water, and voilà, you can enjoy an infused liquid, or coffee. Unfortunately, extraction’s not always easy—or quick. It’s why many people assume there’s no such thing as quick cold brew.

The process can take seconds, minutes, or even days, depending on how it’s done. While investing time into getting the perfect coffee is commendable, I happen to have a ridiculously short attention span and am incredibly impatient—I’m not waiting 12 hours for a drink! So I turned to science, which helped me make a quick cold brew in a fraction of the time it usually needs.

Spanish version: Cómo preparar cold brew en 60 cegundos (sin nitrógeno)

Rapid extraction

The key to extracting espresso in mere seconds is manipulating the pressure. So how do you do that? Well, I rely on one piece of kitchen equipment: the chamber vacuum machine.

vacuum chamber machine

Standard vacuum chamber machine
Credit: Dapper Coffee

What the heck does a chamber vacuum machine do?

The chamber vac, typically used to seal bags, can do a lot more than that. Importantly for us impatient coffee-lovers, it:

1. Decreases pressure to extreme levels, and then decompresses to return to atmospheric pressure.

2. Forces surrounding liquid into a porous solid, and then sucks the liquid back out.

Not sure what that has to do with extracting coffee? Well, let’s explore that now.

Making quick cold brew

vacuum infused cold brew

It’s time to look at the method of making a rapidly infused cold brew coffee. The jargon may sound complex, but the process is actually simple.

Step 1: get a container (any kind that fits in the machine) and put your grounds in it. I use a pretty fine grind with a 1:9 ratio of coffee to water.

Step 2: add water. Any temperature and type is okay I often use room temperature.

Dapper coffee

Step 3: cling wrap the container to prevent spillage. Don’t be tempted to use a firm lid as you want something that can stretch during vacuuming.

Step 4: Set up your machine. I set it to 60 seconds for a syrupy tasting brew. 35 seconds gives me a cleaner brew. Remember that different vacuum machines have different settings so tweak with yours.

Standard vacuum chamber machine

Step 5: close the lid and let the vacuum do its job. Don’t worry if you see no action for the first 15 seconds. The liquid will start boiling suddenly as the pressure has been lowered so much that room temperature has become the liquid’s boiling point.

vacuum coffee

Step 8: Pssscchhhtttt! Decompression just happened. This step is handy because it takes all the air out of the liquid at once.

Step 9: your coffee has been extracted. Remove the cling film and then filter the coffee with a strainer. If you wanted to remove all the sediments, you could even pass it through Chemex or V60 paper. And once you’ve done that, it’s time to enjoy your refreshing cold brew.

pouring coffee

For the home barista

While chamber vacuums are super cool, they are also pretty pricey. Don’t worry, because a hoover actually works just as well. All you need is one of those vacuum bags with one-way valves—the kind you pack your clothes in when travelling.

As seen on Heston Blumenthal’s Blackforest Gateau episode on “In Search of Perfection”
BBC Food Channel – YouTube

Aerated chocolate - the result of vacuum action!

Aerated chocolate – the result of vacuum action!

Don’t limit yourself to coffee

While we all love coffee, there’s also plenty of other things you can make with vacuum infusion.

The process works with any porous solid and any solvent. At my bar, we whip up a deliciously fresh tasting strawberry syrup, which retains the juicy acidity of the fruit (as no heat is involved), and also a spiced rum using white rum, dried oranges and a variety of sweet spices. And of course, all of it is done in a minute or less.

Too good to be true?

So aside from the brevity, why is vacuum infusion so good? Well, it doesn’t compromise the flavours of the coffee, unlike the nitro-method (which I find makes the coffee taste really metallic). All the pure, beautiful flavours and aromas stay true.

It’s easy, it’s quick, and it produces delicious coffee. What’s not to like?

Next week, check in to learn how to filter coffee to crystal-clarity without using a single piece of filter paper!

Perfect Daily Grind