Recently, Meg and I accidentally realized we were vacuum-sealing coffee beans while on a trip. It wasn’t a perfect vacuum, and it wasn’t super-intentional. But I thought it was really interesting, and maybe some fellow science-and-coffee nerds will love it too.
It also made me pose a question, that my internet poking-around didn’t definitely answer. Should you vacuum-seal coffee beans? I don’t have a definitive answer to that, but hopefully this is a fun and nerdy exploration for you. And I think I can help you think clearly about whether or not this procedure is for you.
Our take: Vacuum-sealing coffee can make sense if you buy beans in bulk or want to store coffee for longer than you normally would. For everyday use, though, it’s probably overkill. A good airtight or vacuum canister is easier, and simply buying the amount of coffee you’ll drink within a few weeks is easier still.
How We Accidentally Vacuum-Sealed a Coffee Bag
We Went to Coffee Fest Denver 2018
On a whim, quite a while ago, Meg and I decided to go to Coffee Fest Denver 2018. Coffee Fest seems like a pretty regular (a-few-times-a-year) industry event run by a large conference-throwing company. And it was coming to Denver, which is very near us. And we were going to be in town when it did. So we had to go!
Coffee Fest seems to be making most of its money from special training classes focused at baristas, coffee-shop owners and the like. Oh, and the whole conference is for industry-people only. Which is to say they don’t allow scrubs like us. But we’re (because of this site…) “industry people.” And they took our money and let us in the door.
Bindle Coffee is Great
We love Bindle, which is a local coffee shop and roaster in Fort Collins, Colorado ( my hometown and where we met). The people from Bindle are nice and make great coffee. Plus, they were offering free beans at Coffee Fest. (Megan even wrote about them for Barista Magazine.)
And so, on Saturday afternoon on the way to airport, we had to stop by the Bindle booth, and take our free coffee. We were in a hurry, and so didn’t think about it a lot. But we thought to put the bag in our checked luggage for the flight to California.
Most Coffee Bags Have One-Way Valves
Now, a thing that may not be as noticed by non-nerds as it is by me is that all coffee bags have a pretty cool bit of hardware on them. Some beans I get do come in valve-less bags. But something north of 90% of the coffee bags I’ve seen in the last ten years contain some pretty cool technology: a 1-way valve. The idea is that we need to let air out of coffee, but we don’t want it getting back in. So, these are a great little solution.
The valve is the little plastic thick part you probably see on most bags. Especially if the bag is mostly plastic and a little metal. Those bags are essentially the way that you let the CO2 from the roast escape, but make sure that the bag doesn’t explode and expand in shipping.
Airplane Cargo Holds are Not Pressurized
The last piece of this puzzle is that a one-way valve, coupled with the low-pressure of an airplane cargo hold, leads to all the air around our coffee bean escaping, and not rushing back in.
So, when I pulled the coffee out at our destination, here’s what I found on June 10 (six days after roasting, twelves hours from the plane landing):
These photos aren’t perfect, but they give you a good sense of quite how good a seal the beans had fresh off the plane. Out of curiosity, I let the beans sit a few days.
But Should I Vacuum Seal My Coffee?
In my internet researching of this question of vacuum-sealing coffee beans, one of the problems that people cite is that roasted coffee beans off-gas. That’s exactly what I found when I let these sit, largely untouched. Here are my pictures from the 13th, three days after the photos above:
You’ll notice that I flattened out the base of the base for photographing here. But both to my memory and to the photos, there’s a noticeable loss in tightness of the vacuum around the beans in the bag.
We know that fresh-roasted beans off-gas. We also know that coffee loses freshness more quickly once it’s exposed to oxygen, which is one of the reasons we almost always recommend buying whole beans instead of pre-ground coffee. That’s why we often make time for a “bloom” when brewing relatively newly-roasted coffee. This is, essentially, trapped carbon dioxide made inside of the beans which is concentrated into pockets by roasting. This slowly escapes as beans sit around, even when they’re put into a vacuum. (The gas, when freed from its confines in the bean, gets bigger.)
This makes sense.
Why You Might Want to Try Vacuum-Sealing Coffee Beans
The logic on why you’d go ahead and try to vacuum pack coffee is pretty simple: it takes up less space, and is less exposed to air. These are both benefits, but for different (and differently-important reasons). Let’s examine each:
Vacuum-Packed Coffee Takes Up Less Space
This one is kind of obvious, and pretty minor. If you make your coffee beans have less air between them, they’ll have less air between them. Air takes up space (same as everything else 🤓) and so you can take less space with less air.
I admit, this benefit pretty small and silly. Most of the space my coffee takes up isn’t spent on the air between beans. It’s the excess packing material that surrounds that air-and-bean combination. And most ways I can think of vaccum-sealing your coffee, you’ll still have some excess packing material. So your benefit may be more than zero, but not by a lot.
Vacuum-Sealed Coffee Should Be Fresher
This one is what I was hoping my research would find a definitive article on, and it definitely didn’t. Turns out, our article on vacuum-sealing coffee beans might be the best the internet’s got right now! I think it’s reasonable to assume that oxidation is bad for roasted coffee. (It’s oxygen, that thing that keeps us alive, that makes most food spoil.) I found an article saying as much about coffee freshness.
If, indeed, oxygen is bad for coffee, then decreasing the amount of oxygen (and air, which is typically ~17% oxygen) around the beans would make them last better. Decreasing the amount of oxygen in contact is the same reason that I’ve seen people use wine preserving gas on coffee, wine, and liquors.
(Very random aside: those bottles are comically light. I think because they want them to be at relatively low pressure for shipping safety. So they’re very unlike an oxygen tank, and they’re just gas inside.)
It follow that if you don’t want to use an inert gas on your coffee (which would be a viable alternative) you should vacuum-seal it if you can. Vacuum sealed coffee would have less oxygen around it, it’d thus oxidize slower (or not at all) and then taste good for longer.
How Would You Vacuum-Pack Coffee?
I’ve never vacuum-packed coffee with a machine. Not once. So I’m not going to pretend I have a preferred vacuum sealer after years of exhaustive testing.
If I decided to take seriously the idea of vacuum-preserving my coffee, I’d probably buy a FoodSaver. They seem to be the consumer-vacuum-packer brand that has succeeded. You can buy supplies for them anywhere from Amazon to Walmart.
I’d just take my coffee, divide it into reasonably sized portions, and seal little bits at once. For me, that’d be something like at 32g batch for a Kalita Wave pour over. When I wanted to use the coffee, I’d de-vacuum it. Grind it. Brew it. Drink it.
Coffee storage options, from easiest to most involved
Here’s a quick summary of the coffee storage methods our readers actually use (thanks for writing in the comments, folks!).
| Storage method | Best for | Our POV |
|---|---|---|
| Original coffee bag | Most people | Usually good enough if you’ll drink the coffee within a few weeks |
| Vacuum canister, like the Airscape or Fellow Atmos | Everyday storage | Easier than sealing individual portions |
| FoodSaver + bags | Bulk coffee | Useful if you already own one |
| FoodSaver + Mason jar attachment | Reusable bulk storage | Less plastic, but still more work |
| Single-dose vacuum packs | Long-term storage / freezing | Most obsessive option |
If I wanted less oxygen around my beans without turning coffee storage into a weekend project, I’d probably choose a vacuum canister like the Fellow Atmos before buying a dedicated vacuum sealer.
Downsides of Vacuum-Sealing Coffee
- Off-gassing (which we discussed above) is likely to make your nice tightly-vacuumed portions slowly expand. Especially if you do it when your beans are relatively fresh.
- It’d be time-consuming to make all those vacuum-packs. As I mentioned, I’ve never really used a vacuum machine. But even the quickest I’ve observed take almost a minute of cutting, preparing, and sealing the thing you’re using it on.
- You’re going to use lots of excess plastic around your beans. I feel like conventionally packed coffee, like the Bindle above, is fine on waste. It’s not great, but I’m not embarrassed. Packing 2-4oz packages on your own after getting those would be wasteful. Uncontestably so.
Vacuum-Packed Coffee is Cool, but Buying What You Use is WAY Easier
In general, I thought it was fun and interesting to accidentally vacuum seal coffee. If I magically came into possession of both a vacuum-sealer and a whole bunch (1kg/2lbs or so) of great coffee for home use, I’d probably try it in earnest.
But for me, the solution is easier than vacuum-sealing 32-gram packets of coffee like I’m provisioning a tiny caffeinated spaceship.
Buy the amount of coffee you expect to use in the next few weeks. Keep it sealed, away from heat and sunlight, and grind only what you need. If you want something a little more serious than the original bag, a vacuum coffee canister is probably the sweet spot.
And if your problem is simply buying too much coffee at once, a coffee subscription, like Trade, can solve that in a completely different way: smaller amounts of fresh beans showing up on a regular schedule, without the sealing-machine shenanigans.
We buy ours in bags from Sam’s club. Natural no additional flavors or ingredients and in bean form but when we get home we put it in Mason jars and seal it to retain the fresh smell and oils. Its definitely different and smells different as well.
I use widemouth mason jars and the Foodsaver jar sealer attachment to store my coffee beans. It lets me store my vacuum sealed beans in jars which are about the same size as my grinder’s hopper. So far so good. I’d feel too guilty using all the plastic the bags would require… If you already have a Foodsaver it’s just a few dollars more for the attachment – I find the wide-mouth one works 100% of the time, where as I struggle with the regular sized one.
Ron, do you freeze the beans after vacuum sealing in the Mason jars?
Use two flat canning lids instead of one when using regular size lids The top one usually falls off when taking the foodsaver attachment off
Why not just vacuum seal with an 02 absorber to counter the off-gassing
“use widemouth mason jars”
Yes. that’s good Idea, I notice that Foodsaver plastic bag leaches out coffee flavor, bag eventually turn brown. And why is it that all the coffees on supermarket shelf were lost vacuum?
As someone who owned a set of tools for sous vide, I would say vacuum beans into small single serving bags aren’t much of an effort personally. It is extremely quick and easy plus you can always reuse those bags, esp those designed to be reused, for the same beans at least (or just wash the bags and turn them inside out for drying)
I am surching who does vacuum contract packaging, I want to pack beans
Hi there,
Passenger airline cargo holds and cabins are pressurized just the same. Equivalent to the atmospheric pressure at 8000 feet. With the exception to the Boeing 787 with is pressurized to around 6000 feet. The whole plane is a cylinder to resist the pressure difference outside the plane. If the cargo hold below your feet wasn’t, the floor would bend as the pressure difference on that flat surface would be eminence. Plus, live animals travel in the cargo hold too. They can’t survive at the atmospheric pressure of 35,000 feet. Hiking to high altitude with sealed containers will yield the same result.
I use mason Jars where applicable for vacuum sealing.
I use a large FoodSaver container that fits a 2.2 LB bag of beans. I keep just a small amount of beans in the grinder hopper to minimize air exposure and reseal the container. Takes no effort, considering the sealer is always on the counter. With daily espresso and morning cappuccinos, I refill the hopper about every other day.
We buy a lot of the Dunkin Donuts coffee from where the shops where they sell coffee. The grocery store DD coffee is not the same as what they sell at DD stations.
At Christmas time they sell their coffee for as low as 4 bags for $20. These bags are all one pound bags.(16 oz) and we stock up during this time, so I will suck the air out with my foodsaver machine. I like the foodsaver because the heat strip is wider for a stronger seal.
I would question pulling a vacuum on coffee beans. You would be better off, it seems to me, to place the beans under an inert gas with a moderate pressure above atmospheric pressure.
The vacuum encourages a speedier gas flow out of the beans.
If using sealer bags, the vacuum simply pulls air out of the bag. It does not maintain a vacuum on the product once it is sealed. I would agree that maybe that would be the case of using vacuum canisters, but not bags.
That would only be true if the beans were still at atmospheric pressure. There is no pressure difference, no flow is encouraged. Your physics is flawed.
Hi David & Meg, thanks for your article on a very intriguing question.
Possibly of interest to you:
Way back in the ‘90’s I got a year’s free subscription to the USA magazine Camera & Darkroom for suggesting a way to extend the life of photographic chemicals; and I have, over the intervening period, used it for many other applications – coffee beans included.
Very simple: use any bottle, big or small as needed, with an appropriately sized neck and utilize the Vacu Vin ( wine preserver ) rubber stopper and associated separate manual vacuum pump.
Thus one can have a number of stoppers and 1 pump. Just google Vacu Vin Wine Preserver and there is a lot of info on it. ( It achieves about an 85-90% vacuum ).
Using the bottles is appealing as it’s glass and reusable. And quick and easy to re-apply a vacuum after pouring out beans dosage. Also, I have put these in both fridge and freezer.
Thus a good starting point for anybody who wants to do some comparative experiments.
All the best
Derek McKenzie
Calitzdorp
South Africa
As a beer brewer and a coffee roaster, I believe CO2 is beneficial to maintaining both products for longer periods of time. When brewing, the CO2 keeps the beer from turning bad while in both the carboy, keg, and bottle. Brews that don’t have that protective layer of CO2 tend to go sour or bad sooner, or are bad right out of the carboy. I can say I feel the same goes for vacuum sealing right after roasting. The process pulls out the oxygen, and as the beans gas off CO2, fills the bag around the beans and allows them to maintain their freshness. I tend to not roast more coffee than I can use in 15 – 21 days at a time, but when I have to do some roasting for longer periods, I use this method. Once opened, the gas dissipates and the coffee smells and tastes great, even months later.
Just use a larger bag that can expand. It really works well for me.
Have you frozen your vacuum sealed coffee beans? If so, do you think freezing changes the flavor profile too much?
I am now finding good reason not to vacuum seal coffee! The “Off Gassing” of Co2 that the bean produces provides a protective barrier against oxygen, the oxygen that will eventually make coffee bean stale. In vacuum sealing the coffee this Co2 gets pulled from the bean prematurely, when the oxygen is let back in on an everyday basis to remove coffee beans for brewing and grinding, the Co2 is replaced with oxygen, causing premature aging of the bean… Just something to ponder!
Thank you, this was what I was questioning and it is logical. Love having a food saver, but not for everything, definitely not for coffee beans.
I vacuum seal coffee on the day of roasting but I don’t use bags with a one way valve in it. So the beans stay fresher for much longer.
I have experimented with just freezing beans in test-tubes that barely hold about 28 grams (one serving) and vacuum sealing, and freezing one or two servings of beans, using small size (Amazon sold) vacuum bags that allow reuse of the same bag several times before they will no longer hold even one serving (at which time I have to add the now-too-small bag to my plastic bag recycling collection), and find that the vacuum sealing works the best to retain the bean’s quality for the longest time (at least several months with no out-gasing (with at least one YouTuber saying that frozen vacuumed beans should last for years)). I am also interested to try Derek’s above mentioned vacuvin/wine bottle method, noting that I have found that only the original (and, I think, no longer available) silicon type vacuvin bottle plugs (that maintain vacuum on fine wine for several days) are effective in holding their vacuum very well, and DEFINTELY Stay Away from buying any of the currently produced Chinese imitation Vacuvin products sold on Amazon and eBay as all their attempted copies are complete crap to even include their imitations of the original bottle plugs and their badly produced imitation vacuvin pumps.
So I have been vacuum sealing (in small bags with a Food Saver) single portions of coffee beans for my espresso. I put the vacuum sealed bags in the freezer, and only remove the bag I will be using that morning. I think my method makes the coffee taste bland. It’s not stale, just not as bright and flavorful as the beans stored at room temp in the original packaging. I use lighter roasts that have lots of fruity bright acidic notes and all of that gets lost and all that remains are the dull more chocolatey notes. What is the reason for this? Is it the freezing or the vacuum sealing or both?
Vacuum sealing whole bean coffee not only pulls oxygen from the bag but also pulls CO2 from the beans prematurely as the CO2 protects the beans from oxidation. Once the coffee is ground vacuum sealing small portions of coffee is advisable as the grind greatly diminishes the capacity to hold CO2, but you will notice that when brewing your bloom will be greatly diminished.
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I use the food saver and mason jar method myself. This morning I took one from the shelf and when I removed the ring the lid quite forcibly blew off scattering beans across the kitchen, about a half cup.They are stored in a cool pantry so I was really surprised by this. Does this mean the Co2 pressurized the jar?
A few Christmases’ ago, by an odd coincidence I was gifted several large bags of coffee. Not wanting to waste them, I vacuum sealed the bulk of them and have kept them in a refrigerator downstairs. I’m still using those beans and TBH, the flavour is amazing. I have not noticed any off-gassing, in that the sealed bags appear to be, well… still vacuum sealed.
I’d debated freezing them, but felt it might damage the beans. So far, vacuum sealed in the refrigerator has been a game changer for me. My original supply is dwindling, so I intend to keep an eye on deals and will purchase in bulk and vacuum seal and keep in the fridge again.
Wow, that was not the wave tops for a potentially quick and simple answer. Yes or No and a summary of why would have won the day. No, i did not read it. So many people write too much about nothing.
I am using a product called Storage Maid, which has plastic cannisters, lids that have a gasket and a small fitting, and a small battery-operated pump that can be attached to pump out the air. The size of the pump suggests I’m not pulling a big vacuum. It takes a couple seconds to release the vacuum, with a mild hissing sound. So, no improvement in ground-coffee storage life that I can tell, but the modest vacuum may be a reason. I have also read (here and elsewhere in my google search) about the bad effects of removing the oxygen: for coffee it can hasten CO2 outgassing and, for protein-containing foods, removing oxygen can accelerate the growth of anaerobic bacteria that can make you sick (see https://en.m.wikipedia.org/wiki/Botulism about that). I think I’ll go back to closing the bag tightly.
I wonder if it’s smart as some people are saying, to vacuum in glass. If they do off-gas, plastic would expand but I’d think much expansion would increase the risk of breaking the jar.
I am definitely going to be using both jars and bags but I tend to save my jars for herbs, or for canning.
Great article. Thanks.
Please check on the Oxygen percentage in Room Air.
Textbook values are 21% ( 20.9% actually ).
What I have found is I close but not seal the beans for two days which releases a lot of the CO2 and then vacuum seal the bag and the unroasted beans last for a long time several years and you cannot hardly taste the difference and they smell fresh when you open the bag .
Dan
Do you also freeze or refrigerate them?
https://mtpak.coffee/2022/11/vacuum-sealers-effective-sealing-method/
I have used a stainless steel container with a built in (replaceable) one-way valve for several years with limited success.
I find the best taste “sweet-spot” is between four days and ten days after roasting of the beans.
I am about to start a trial using vacuum sealing using my Zwilling vacuum pump with a suitably sized Zwilling vavuum container (AU$35) for 1kg of roasted beans,
As an aternative, Fellow already make a vacuum container for US$75. I have read (one) post which claimed the seal only lasted 12 months before the silicone seal started to leak.
https://fellowproducts.com/products/atmos-vacuum-canister
As I already have the Zwilling vacuum pump and a new container, is only going to cost me AU$35 to find out if vacuum storage really does make a difference.