Before I start writing about how I did this, I wanted to say that all my results are based on taste. It's still a test method and after doing some research on the internet, I found that a few people have tried this method and have had some good and bad results.
The other night I was on the couch watching Heston Blumenthal and the weird and whacky stuff he does. He started talking about the vacuum infusion process and how you can cook with it. So I Googled it and found some interesting facts and thought this process could actually work for accelerating the cold brew process.
According to Martin Lersch, it works:
"[w]hen the pressures is suddently [sic] released (and it is important to release pressure as fast as possible) the sudden pressure drop causes the dissolved gas to nucleate and form bubbles which expand and disrupt cells, thereby releasing flavor compounds."
What you will need:
- Vacuum bag or Space Bag
- Metal or paper filter
- V60, Chemex or Kalita or plunger (for filtering purposes)
- Vacuum cleaner
- Freshly ground coffee
- Wooden stirring spoon
1. Get a tupperware container that is big enough so that 400mLs of water only fills half the container. We want a large surface area for the coffee to be saturated. Grab the container lid and punch a hole into it.
2. Weigh out 40 grams of coffee. Grind the beans to a fine (espresso) grind. I have been using an espresso roast instead of a lighter roast.
3. Add 400mLs of filtered water and saturate all the grounds. Grab a spoon or a wooden paddle and give the coffee a little stir.
4. Place the lid onto the container and put the container into the vacuum bag. Make sure you place the one way valve of the vacuum bag right over the hole you made in the lid.
5. Now grab your vacuum cleaner and suck the air out. You'll know when to stop.
6. Place the lid over the valve and tighten. Start your timer. I brewed the coffee for about 8-10 minutes. At around 4-5 minutes grab your vacuum and suck the air out again.
7. Release the vacuum and filter your brew. This part is a little painful and messy. There is a lot of coffee sludge so filtering the brew talks a while. I suggest you use a metal filter and then a paper filter. However, just a paper filter can do the job. Make sure you rinse the paper filter with boiling water to remove that paper taste. Rinse the paper filter with cold water after the boiling water, we don't want to introduce any heat.
8. Once it has been filtered you should have a pretty nice and quick cold brew. Serve over ice or place in the fridge.
All my methods are straightforward and simple. I hope they give you an understanding to brew better coffee to the taste you like.