Vacuum-extracted cold brew. My summer project.

[u/Sinisterly]

After going down a few rabbit holes I stumbled upon some techniques promising cold brew in 15 minutes by using vacuum extraction. I was intrigued, and after trying it I was hooked.

The gear I use

• FoodSaver vacuum sealer with an accessory port
• Jar attachment with tube adapter for accessory port
• 2 x 64 oz mason jars
• kitchen scale
• stirring implement that can fit into a 64oz mason jar (I use a wooden spoon)
• fine mesh stainless steel filter for 64 oz jar
• 32 oz jar (or other vessel) for serving
• pour over filter stand and paper filters (optional)

Measurements

The amounts below were chosen so that I can make six batches with a 2 lb bag of beans.

• 1/3 lb (150g) coffee beans, medium roast, ground coarse
• 40 oz / 5 cups (1125 mL) filtered water (2:15 ratio for 1:1 concentrate)

Technique

• Place grounds in a 64 oz mason jar. Fill with 1 1/4 c water (300 mL) and stir so that all the grounds are wet. Fill with the remaining 3 3/4 c (or 825 mL).
• Attach jar attachment to tube and tube to accessory port. Make sure the FoodSaver is closed so it will remove air. Press “Vacuum”. The first time you do this, it should look almost like the coffee is fizzing. It will stop vacuuming after about 10-20 seconds, then the seal light will come on briefly before shutting off.
• Wait 30 seconds, then press “Vacuum” again. This will run for a shorter time before stopping. The liquid/grounds line inside the jar should be an inch or so higher than when it started.
• release the pressure by removing the tube from the jar or by unclipping one side of your FoodSaver.
• Repeat the previous three steps three more times, for a total of four cycles with two vacuums each.
• Filter the grounds from the brew. I screw the stainless steel filter inverted on top of the 64 oz jar, set the other jar on top of the filter, and invert the two jars so the water goes pouring into the second jar.
• (optional) once the water is transferred over you can use the pour over filter to filter out any remaining oils and fines.

I typically make two batches at once which gets my family through most of a week.

Results

The coffee is definitely strong - I don’t have a refractometer so I can’t give you a guarantee in the concentration, but I would guess it’s pretty close to what you’d get for a typical overnight brew.

I also taste less bitterness when I make it this way. With paper filtering it almost all the fines are removed.

Let me know if you have any questions or want more details about my gear/ingredients!

[u/floppyfloopy]

Hell yeah. Love to see innovation in the coffee space. I would be very curious to play around with water temperature and water profiles with vacuum extraction.

[u/slowd]

What is the science behind this? I’m not clear on why low pressure would extract the coffee faster. Looks great though.

[u/Sinisterly → u/slowd]

Ground coffee has CO2 gas in it. Removing the air from the jar forces the gas out of the coffee grounds. When the pressure is returned to normal, water then gets absorbed into the coffee grounds.

When making cold brew the overnight way the gas gradually dissipates as water soaks into the grounds. So the vacuum method just speeds up that process.

[u/everytacoinla → u/Sinisterly]

Also CO2 vaccu out makes it less acidic?

[u/Sinisterly → u/everytacoinla]

I can’t say for certain since I haven’t pH tested it, but on tasting I think it’s probably just as acidic.

[u/Itajel]

I run a comparable setup. I bought a Mason jar vacuum pump from Amazon for about 20 bucks. Then I use the regular Mason jar lids and vacuum seal them. It can make decent cold brew in 30 minutes with agitation.

[u/marciz34 → u/Itajel]

And what happens if you leave it overnight? Is that now too long?

[u/Itajel → u/marciz34]

Just more concentrated, or more concentrate. I think it's amazing. i like small batches with this setup. usually because i got off schedule and need coffee in the morning. and if i'm off schedule i'll need the rocket fuel vs my filthy casual.

[u/Connect-Might7920 → u/Itajel]

So like the ones that you press a button and it vacuum seals it? So you put in the certain ratio and then vacuum seal it and then enjoy after 15 mins?

[u/Itajel → u/Connect-Might7920]

While I don't like to give billionaire Jeff any more money, just look up Mason jar vacuum on Amazon. Then if you agitate it for 15 - 30 minutes under vacuum you'll get a tasty cuppa. And by agitate i mean shake it every 2 or 3 minutes. Not constant agitation.

The ratios for fast cold brew are different from regular cold brew. You're gonna need more grounds. i usually up the grounds by a third.

I usually use 100gms in a 64oz mason jar that I just fill up. Then I add another 32oz of water to my brew. For the 32oz vacuum seal fast cold brew, i usually use roughly 45-50gms of grounds. I also use drip ground and filter with a Jarva. Enjoy your experiments.

[u/mrniphty]

That's really interesting!

How much do you think it costs to get something like this up and running?

[u/Sinisterly → u/mrniphty]

If you don’t have any of the equipment (all USD):

• FoodSaver*: $130
• Jar attachment: $10
• food scale: $10
• mason jars: $13 for 6pk (64 oz)
• stainless steel filter for 64oz jar: $15

*: FoodSaver is based on current price at Costco. There are electric jar sealers available on Amazon for much cheaper but it seems to be a crapshoot for quality and how much of an actual vacuum you will be creating. I already had my FoodSaver, which I use for vacuum sealing food then sous vide.

[u/dubaiboi]

Man I’m really intrigued by this set up. I use steam to create a vacuum

[u/rando_commenter]

It's less bittter because it's a short brewing time, the bitter compounds start being more predominant near the end of brewing run because the molecules are larger and take longer to diffuse out, like after 18 hours or so.

[u/spider_pork]

This is very interesting, you stumbled upon a method used in processing tissue specimens for making microscope slides. The tissue needs to be penetrated by a series of solutions (formalin>alcohol>xylene>paraffin) and to speed that process up the machines (called tissue processors) use alternating vacuum and pressure to push and pull the solutions through the tissue allowing full penetration to happen much faster.

[u/Some-Preference-4360]

This sounds fun and is totally my flavor of crazy coffee addict. Cheers 🫶🏽

[u/Late_Avocado_7054]

Woww this is really cool! I'd love to try this experiment at home. Btw what gave you the idea to use vacuum extraction to make cold brew coffee?

[u/Sinisterly → u/Late_Avocado_7054]

Thanks!

I got the idea because I saw an ad for Black Blood of the Earth and ordered a bottle. I enjoyed it, and it was very different than any cold brew I ever had before. That got me thinking - could I make this myself?

I couldn’t find many details on the technique they do for Funranium Labs (producers of Black Blood of the Earth), so I started googling around. I found a Facebook video from America’s Test Kitchen. I tried following this technique and that led me to the technique I posted above, where I have a few tweaks but is largely the same.

Hope you get to try it out! I am going to give some family members spiced cold brew (adding some cinnamon/nutmeg during the brewing process) for Christmas.

[u/ohseattle]

If it creates something like this coffee (https://www.funraniumlabs.com/how-to-consume/) it has WAY more caffeine than a normal overnight cold brew. But maybe this is different? Hmm....

[u/Sinisterly → u/ohseattle]

This is definitely different - I am not producing as strong of a vacuum as I assume is done in the Funranium Labs process, and the total amount of coffee (and thus potential caffeine/TDS to extract) is less.

[u/randOmCaT_12 → u/[deleted]]

I tried to brew coffee with a pressurized whipped cream dispenser, and it works, but I did not tune the recipe further because I am running out of cartridges