Chances are, if you came her from a search engine, that you have an idea what vacuum cold brew is, but you want to know more about it. Relatively new on the market and as an extraction method in the coffee industry, the chemistry behind vacuum cold brew has been around for a long time, it was just not applied to coffee.
In this article we will explain what vacuum cold brew is, how does it work, and it’s better than other cold brew methods, such as immersion, or drip.
A little spoiler, vacuum is head and shoulders above any other extraction methods. But let’s dive in, and see what makes vacuum technology so special, and how does it solve the problems of both traditional cold brew and regular hot brewed coffee.
If you are looking for a vacuum cold brew coffee maker review, we have another article on the topic: “Best Vacuum Cold Brew Coffee Makers“. This article discusses the technology, and ho it improves the cold brew making experience.
What is Vacuum Cold Brew
Vacuum cold brew is a method of coffee preparation with cold water, that uses vacuum as the method of extraction. The vacuum speeds up the extraction time, by decreasing the water boiling point.
Vacuum cold brew decreases the pressure in an air tight container, were we place coffee grounds and water. A suction method is used to remove all of the air in the recipient. The lower the pressure in the recipient the more efficient the extraction. But let’s see how that works, if you want to dust off your chemistry knowledge.
We all know how much we love, coffee. But we also know that coffee can be a bit of a loose cannon, right? It’s a volatile drink, which means we have only a few precious minutes to enjoy it in all its glory. And for those with sensitive stomachs, coffee can sometimes be a bit of a challenge.
Cold brew seems to be the answer to both stomach sensitivity, and coffee’s shelf life. Cold brew is a stable beverage with a shelf life of over a week when stored in the fridge, and it’s perfect for those who want to enjoy one sip at a time. Also, it is common knowledge that cold brew is easier on the stomach.
The only downside? It takes a long time to brew.
Enter vacuum technology. Vacuum assisted cold brewing solves all of the problems associated with traditional cold brew.
The history of the cold brew is relatively recent, as I already mentioned. The first recorded article I could find is this chamber vac cold brew guide, from 2015. But I am pretty sure others have mentioned it before, I just couldn’t find any mentions of it.
The Low Boiling Point Is the Key
When we decrease the pressure in the airtight recipient, we are increasing the kinetic energy of the brew, and as a consequence, the boiling point. Why do we care about the boiling point, you ask? When water boils, the kinetic energy in our brew increases dramatically. And it is this energy that speeds up dissolution.
This is why traditionally we use hot water to brew coffee, because we have a faster dissolution, and faster extraction time.
In vacuum, water’s boiling point lowers to room temperature. We don’t really need to boil the brew, similarly to a hot brew. We just need to bring the slurry close to the boiling point, so that it extracts faster.
We can have cold brew coffee in a matter of minutes rather than hours or days. To put it in simpler terms, vacuum cold brew is like the espresso of the cold brew world, delivering a quick and intense coffee experience. It’s exciting to see this new method bringing more convenience and speed to the world of coffee brewing!
Maybe not as important as the low boiling point, there is another benefit of using vacuum. The suction power helps the coffee grounds saturate with water faster. With immersion cold brew this process is very slow, especially if we grind very coarse. The suction will completely wet the coffee grounds in seconds.
Advantages of Vacuum Cold Brew
Vacuum cold brew has several advantages that make it a great way to brew coffee.
Vacuum cold brew coffee has several advantages, including a fast brewing time that leads to a stable yet delicious coffee with a longer shelf life, eliminating the need for refrigeration, and reducing the risk of contamination due to the fast brewing process. The vacuum infusion method preserves the freshness of the coffee for weeks, and it is ultimately cheaper and fresher than classic cold brew.
Because it’s cold brew, it is gentler than hot brews on the stomach, so for many people the health aspect is the most important. The difference is that vacuum technology brings convenience, and more flavor to a healthier caffeinated drink.
Vacuum Cold Brew Preparation is Fast
One of the most significant advantages is that coffee brews much faster in a vacuum. I don’t need to explain this, but you get a better coffee in 10-15 minutes, compared to immersion cold brew – 12 hours minimum.
How many times you wished you didn’t delay preparing the new batch. I know I did, many times. So you are not dependent on time for your cup of joe. You can get that instantly. Although this looks like the most important thing in our minds now, it is not the only benefit.
Reduced Risk of Contamination
One of the benefits of vacuum cold brew is the reduced risk of contamination. With regular cold brew, the slow extraction process can create an ideal environment for bacteria to grow if proper hygiene practices are not followed. In contrast, vacuum cold brewing allows for a much faster brewing time, which limits the opportunity for bacteria to develop. So, if you’re looking for a quick and safe cup of coffee, vacuum cold brew might be worth considering!
Additionally, we eliminate the need to refrigerate the slurry during the brewing process. It doesn’t affect us, the home baristas, but this is a considerable expense for cold brew producers.
Flavor Profile, Antioxidants, and Other Vacuum Considerations
When vacuum coffee is produce commercially, companies can transfer the final product directly in cans. This allows them to extend the shelf life of the canned cold brew for longer times. Regular immersion cold brew starts to oxidize after the first 6 hours. That means coffee starts to degrade before it’s ready. Because vacuum infusion speeds up the process giving us a great tasting coffee, with most of the antioxidants intact, and with a great flavor profile.
With immersion cold brew you lose something, no matter what. With vacuum cold brew you win no matter what. I’ll explain a bit this.
I love a stronger coffee. Espresso is one of my favorite concoctions. I choose to brew my immersion batches longer, and grind finer, to get a higher TDS. These two choices will result in some chlorogenic acid loss, and in a muddier taste. But in my experiments, this works best for immersion cold brew.
Now this is totally different for vacuum cold brew. There is some research where coffee specialists determined that a coarser grind results in a tastier coffee. But this is for vacuum cold brew. Using a sequence of seven pulse vacuum cycles, and a coarse grind, the specialists obtained a cup with interesting acidity, and a high amount of lipids. This sounds better than espresso.
Storing coffee in a vacuum is also a great idea. It stops the oxidation process by removing all the oxygen in contact with coffee, which extends the coffee shelf life to months instead of weeks, as with regular cold brew. For storing brewed coffee in vacuum, you don’t need the same pressure as with brewing. Overall, vacuum cold brewing is a great method for making fresh, tasty coffee that lasts longer and requires less processing than traditional brewing methods.
Vacuum Cold Brew Coffee Makers
There aren’t many vacuum cold brew coffee makers on the market at the moment. The technology is young, and it is pretty expensive. But cold brew as a preparation method is getting more and more popular, because of its practical and health advantages.
The early adopters started with a chamber vacuum machine, but this is an expensive piece of equipment and not everybody can afford it. In time, the entrepreneurs saw an opportunity and developed various solutions. Some of these look deceivingly simple, but they are not.
AirVac One is a glass carafe with a extraction piece sitting on top of the carafe. People compare it to the vacuum syphon, but it is very different from that. The vacuum syphon works with heat to create vacuum, but AirVac One uses an electric motor to create the suction.
Dash is another success on the market. It can brew coffee or concentrate, depending on your needs. It’s very easy to use, and the price is okay.
Gourmia Brewdini is the last example of our domestic cold brew coffee machines, and it is equally good.
The simplest solution is a mason jar with a vacuum sealer, which you can improvise into a home-made vacuum cold brewer.
As far as the commercial vacuum cold brew, Bkon is probably the most reputable company, with nice advancements in large batch cold brew. They were looking at launching a home brewer a while ago, but it seems like the project is on hold now. They are still taking extraction orders for commercial cold brew companies, as this is their business model.
There are obviously many other failed projects, as you’d expect with new technology. Some of these have good chance of getting revived, though I have seen a lot of them dropped. The Cub Cold Brew Coffee Maker is one of the products that didn’t make it on Kickstarter. However, it is a promising project in my opinion, just didn’t have the right marketing.
As a conclusion to this introduction into vacuum cold brew, I encourage you to get one of these coffee makers and try it yourself. If you are into cold brew coffee, vacuum is the way to go. Buy one, or just improvise your own for acceptable results, but just try it. You will never go back to immersion cold brew.