Some Strategies to Keep your Coffee Fresh

There are few things more annoying than discovering some of your favorite coffee beans are getting stale and taste much worse than when you first opened the bag. I experimented with various methods to keep coffee beans fresher in the last six months, and I would like to share some of my findings in the form of different options you could adopt.

In short, there are four things you want to keep your coffee away from: oxygen, humidity, heat and UV light. All of those can damage coffee over time. The various tools and approaches described below are therefore designed to protect coffee from one or more of these factors.

Original Packaging

Freshly roasted coffee degases a lot of CO2 for a short amount of time. If it is quickly sealed in a bag with a one-way valve by your roaster, this will contribute to expel some of the oxygen that was initially present in the bag, therefore creating an even better protection against oxygen. When you open the bag for the first time however, all of this CO2 immediately leaves the bag and gets replaced again by the average air composition, with all its oxygen. The coffee does not have that much more CO2 to release anymore, and therefore this newly added oxygen will be free to slowly damage the coffee with oxidation. This effect becomes even more marked when the bag gets almost empty, because then you have more air (and therefore oxygen) in your bag that is free to attack a smaller amount of coffee.

These considerations explain why you can get a great cup from a freshly opened bag roasted a month ago, but within just a week or so after you opened that bag, the taste will quickly degrade unless you take proper care to protect your coffee against oxygen.

Generally, it’s a good idea to open the original bag only when you brew your first cup of coffee with it. You still need to keep the bag away from heat, and it’s good not to shake it too much and store it upright so as to keep its CO2 reserve intact.

Opaque zip-locks with valves

One of the easiest ways to quickly store coffee in a safe place is to use opaque and hermetic zip-lock bag with one-way valves such as these ones. They will protect coffee from humidity, UV light, and also from oxygen up to a point. A lot of roasters already sell their coffee in high quality bags like this, but I find it useful to have a few of them for the moments where I discover a roaster did not add a zip-lock to their bags for example (I’m looking at you with an angry face, all roasters who don’t). Just make sure that you get as much of the air out of the bag every time you close it.

Inert Gases

Bottles of inert gases (typically CO2 and nitrogen) can often be bought in wine stores for about fifteen dollars a bottle. They are a bit hard to order online, but it is worth getting a few of them as a nice addition to zip-lock bags; you can just push the oxygen out of the bag by adding a small amount of inert gases in the bag just before sealing it.

Here’s how I use inert gas bottles: Put the bottle’s straw through the zip-lock, and almost close the zip-lock bag except for a small opening where the straw is. Get most air out of the bag by pressing on it with your other hand, and with your hand still pressed on the bag, give a small 1-second push of inert gases (you can make it 2 seconds if you have a very large and almost empty bag). Immediately remove the straw and close the rest of the zip-lock bag. A typical inert gas bottle will last for a bit more than a hundred uses like that.

You will need to do this every time you open and close the bag however, so this is not a particularly great solution if you constantly brew coffee. In these cases, oxygen pads (more below) are a better solution.

An inert gas bottle.

Vacuum Sealers

Vacuum sealers require a bit more work on your part, but in my opinion they provide one of the best ways to keep your coffee fresh, especially in the long term when combined with other methods. I had amazing coffee vac-sealed months ago with no hint of oxidation whatsoever.

I only tried one vacuum sealer yet, and it turns out that it works pretty well for me. It’s probably not appropriate for industrial use, but I have been using it almost every day for more than three months and I had no issues with it. There are two annoying things about it, but I’m not sure which vacuum sealers don’t have these issues, if any. (1) The plastic bags are way too large and need to be cut, which is a bit more work than I’d like; (2) the vacuum chamber is a bit far from the edge of the sealer, so you always need to leave a bit more than an inch empty in the plastic bag.

Here’s how I recommend using this sealer; take one of the unnecessarily huge plastic bags with a ruler and a pen. Make two marks on the bag at 1/3 and 2/3 of its width (excluding the sealed margins). Do this near the bottom and near the top of the bag. With the ruler, use these marks to draw a vertical line at 1/3 the width and another one at 2/3. Use scissors to cut along only one of these lines (if you cut out both right away, the rest will be more of a hassle). Use the vacuum sealer in heat-seal mode (not vac-seal) to seal both sides that you just cut out. Cut along the second line, and heat-seal both sides again. You now have three thin and long bags; those are much more useable sizes in my opinion, and they will save you plastic in the long term because you will minimize the empty portion of the that the vac sealer forces you to leave.

When you fill a vacuum bag with coffee, I recommend using a relatively large funnel – just make sure the mouth will let beans through without clogging first. As I mentioned earlier, make sure you leave enough space at the top of the bag to seal it properly. I suggest marking what coffee this is and the roast and seal dates at the bottom (not the top) of the bag. The thing that is really neat with this format is that you can easily cut the bag open, weight a single dose out of it, then immediately re-seal it with your vac-sealer. Because you are freeing up more space than you are cutting out every time, you will even be left with a smaller but re-usable bag.

It’s always good to leave your vac-sealed coffee bag on the counter for a dozen minutes after you vac-sealed it, especially when you use a plastic bag for the first time. This will allow you to quickly notice if you didn’t properly heat-seal one of the bags or if it was otherwise damaged, because it will become loose. There is also one thing your vac-seal bags won’t protect against: UV light. It is therefore good precaution to either store them in a dark closet or in an opaque bag.

Make sure you store vac-sealed bags of coffee in a dark place, or in an opaque bag.

Freezing Coffee

There is one device in most people’s houses that is great at long-term preservation: freezers. Keeping coffee in the freezer has sometimes been feared by the coffee community. This is probably mostly true because careless storage in the freezer can quickly destroy your coffee. Remember that humidity is one principal enemy of your coffee; this is one that your freezer alone will not protect against.

To protect your coffee against the humidity and potential odors in your freezer, you simply need to seal it carefully. This is very easy to do with vac-sealed coffee, but I recommend putting vac-sealed bags in a large plastic container, because otherwise it’s easy to poke a hole or tear a bag with the other food you store in the freezer. Cheap zip-locks or plastic containers often do not provide a good seal and are at risk of letting humidity in your bag of coffee. I suggest using slightly more expensive sturdy bags with double zip-locks, or tupperwares with a rubber gasket and clips. You can also use something like the Airscape, but I tend to prefer bags because they take up less space as you use up the coffee. But hey, maybe you don’t store 25 different coffees in your freezer like I do.

There’s another subtlety in using the freezer to store your beans. When you take something cold out of the freezer and leave it in contact with air, the ambient humidity will quickly condense on its cold surface. This means your coffee beans will come in contact with water if you open a sealed bag of coffee that is still cold. This is probably not bad for a dose of coffee you’re about to use, but it is really bad for the rest of coffee you’re about to re-seal. I recommend only using the freezer for medium to long term use: when you decide to drink one of your bags of coffee, just take it out of the freezer a dozen minutes before breaking its seal, and then store it outside the freezer.

If you’re motivated enough to single-dose your coffee in the freezer, you won’t have this problem as much, but vac-sealing them will be really annoying. There is a study showing that cold coffee beans shatter a bit more therefore creating slightly more fines in your grind distribution at typical freezer temperatures, so you might still want to let them thaw a little before grinding them.

I read some baristas refraining from using the freezer because they were afraid that the humidity inside the coffee beans would freeze into crystals. However, I have seen Scott Rao mention that this water is trapped in cellulose cells and cannot crystallize as a consequence – I have not seen studies on this, but my taste buds informed me that coffee vac-sealed and properly stored in the freezer for more than a year still tastes great. I also read that un-freezing and re-freezing coffee is bad; I am not sure why and I never tried, but my guess would be that this is either based on bacterial build up or a gradual weakening of the cellulose cells inside the coffee. One last consideration; I read testimonies about how great ultra-low temperature freezers are for preserving coffee, but those are very expensive and I never tried it.

Oxygen Absorbers

Thanks to Matt Perger who recently shared something about this on Instagram, more recently I decided to use oxygen absorber pads instead of inert gases. They are relatively cheap, can be shipped easily, and they won’t get immediately spoiled every time you open a bag. If you would like to know more technical details on oxygen bags, I recommend reading this page. Here’s a summarized version of useful facts: (1) typical 100cc bags can be used to store up to about a pound of material; (2) it takes several hours for the pad to absorb all oxygen from your bag. Oxygen also won’t attack your coffee extremely fast, so this is good because it also means you don’t have to be in a total rush to seal your bag; (3) when the oxygen pad is completely spent, you can feel through the bag that the materials inside it will are clumpy and crystallized.

If you order some of them, you’ll notice that they come vac-sealed. This should not surprise you, because they would otherwise already be spent (it surprised me for 5 seconds). When you break the package open, I recommend placing them all in a large sealed zip-lock (see above). You can then just open and close the zip-lock every time you need one. Just don’t forget the zip-lock bag open.

My Gold Standard for Storing Coffee

Now that we discussed all the tools that I like to use, here’s my gold standard of how I store coffee that I care about:

  • I leave it in the original bag until I first brew it, unless I want to keep it for long term use, in which case I open it right away.
  • When I open the bag, I transfer it to a few thin vac-sealed bags, each with one oxygen absorber at the bottom.
  • I typically keep one of them in an opaque bag at room temperature and store the rest in a plastic tupperware in the freezer.
  • When I want to use a coffee stored in the freezer, I just transfer it to the opaque bag at least a dozen minutes before I use it (sometimes the night before).
  • When I want to brew coffee, I cut open a room-temperature vac-seal bag, get the dose out, and immediately seal it again.

When I don’t care about a coffee as much, I simply put it in a sealed zip-lock if the original bag lacks it, and put an oxygen absorber pad in the bag. Before closing the bag, you can whisper “you should have been roasted better” in the bag.

51 Replies to “Some Strategies to Keep your Coffee Fresh”

  1. I think more roasters could include an oxygen absorber in their packaging, I’ve only seen one roaster do it (Holistik Coffee in Hungary). As you say storing them long term is tricky since they go off all at once once you open the pack, however for a roaster it would be far easier to throw one in one they’re packing all the bags.

    Liked by 2 people

  2. Coffee roasters often have opinions, sometimes quite strong, about when a batch reaches it’s peak for grinding and drinking. Obviously it would be ideal to reach and then lock in the coffee (through the numerous methods you mention) right at that moment.

    What’s your research and/or thinking about when or how to discern when a coffee ages enough to attain it’s ideal drinkability? Does it vary? What does ‘aging’ even mean in this circumstance (lot’s of oxygen at first, no oxygen, maximum CO2 release?).

    Thanks, I’m enjoying the way your articles slowly develop a finer way of thinking about coffee.

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    1. I didn’t do any research about this, so I’m not sure. I suspect it depends on brew method: lots of CO2 probably makes it harder to make a good bloom or reach high extractions with a V60, but probably not with an immersion. This would probably only be important for darker roasts or coffee roasted only a few days ago.

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    2. Hi Roger. I use Ikawa Home roaster to roast 50g batches, so I am able to brew even right after roasting … and I can say, especially with Ikawas small batch size and light roasts that I prefere, that there is seldom a peak in taste later than a day or two. On the other hand I tried to make espresso right after roasting, using the NOx cartridge in ISi bottle to remove CO2, and though its a different experience than having it the next day, its very interesting too … though the taste is a bit more jaggy, not as rounded. I dont think there would be much benefit of letting the beans oxidize for a few days then packing them as suggested – I think most of the recommendations are for espresso making where you would have problems with the CO2 in the beans. Its something that could be tested though .. I really liked many of the ideas in the article so I will probably try most of the suggested, so if I will do a batch stored right after cooling and another after few days of rest I will report back what it may do. My gut feeling tells me though that there should be some product of roasting process that may have a short life or just evaporate fast, and other that react after roasting with each other … so I would not think oxidation is too important for the good “aging” of the beans.

      Btw the oxygen absorbing pads .. thats really brilliant … dont know how expensive they are but it seems way better for a roastery to handle than the inert gasses. Hope to see them being used by roasters more …

      Liked by 1 person

      1. I believe some coffees have a peak later when they get rid of some highly volatile aroma. Your gut feeling is correct, one coffee aroma component (methanethiol) is particulary volatile and susceptible to oxidation and it does not have such a pleasant aroma. It is the compound added to natural gas to make it detectable by smelling. But fast doesn’t mean here 1-2 days, it is more 5-10 days.
        My feeling is more that the excess CO2 released during brewing is preventing good extraction, and this is the main problem of fresh coffee. Less of a problem with filer and more for espresso, obviously. Of course, it depends as well on the roast and coffee quality. Darker roasts and low quality coffee does benefit on getting rid of some of the aroma during storage, because there is just too much of unpleasant smelling compounds in a freshly dark roasted bean.

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      2. Yes, this all makes sense. I think there may also be some positive aromas that can leave after weeks, even when
        vac sealed. I also noticed that vac sealed coffee seems to degas slower than non-vac sealed coffee. I’m not yet sure why this is, but it could just be a matter of “accessible” surface area. I ground some individual doses and vac sealed them for travel, and noticed that one of them had not perfectly been vacuumed before the seal was applied, so there was a very small amount of air inside. The day after, it had completely ballooned, I assume from CO2 degassing, while the other doses had not. The close packing that vac sealing creates probably helps prevent degassing of all particles except those right next to the plastic walls.

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  3. One other thing (if you’ve already received this I may have failed to log in correctly). As you likely know, but don’t mention in your article, Food Saver makes varying sizes of thick, strong vacuum containers that can be repeatedly vacuum sealed and then put back in the freezer. My freezer space is limited and I’m not storing 25 different coffees like you (although that “is” an interesting idea!) but I’ve used Food Saver plexiglass (?) containers for years with rarely a seal failing.

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  4. Nice article as always Jonathan! If after my 1st brew and opening the original bag I do my 20g batches into standard 10x7cm zip-lock bags and put those into Coffeevac which I then open twice per day, does it still make sense to put 1 oxy-sorb into Coffevac? And when do you think the oxy-sorb will need replacing for now one under these circumstances?

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    1. Hi Jakub, not really because your ziplocks are isolating your beans from the interstitial air inside the Coffeevac. If the ziplock seals are not perfect and you don’t often open your Coffeevac, then it’s possible it would help a bit. I would recommend to change the oxygen absorber when it feels like it crystallized to the touch.

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  5. I would also love to find some small bags to make things a bit easier. The first suggestion from bytheway only works with vacuum chamber models, which are nice but usually go for over a grand. The second item looks great, too bad it ships from the UK and therefore the postage is quite expensive.

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    1. I agree. I’ll let you know if I find small ones compatible with lower-end vacuum sealers. The best method I have yet is take a ruler & pen, mark then at 1/3 and 2/3 the width and use an exacto cutter + glass cutting board to cut a couple sheets at one. It’s still a pain.

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  6. Just a question did you do any sensory testing with the various forms of packaging. I have read sensory results that show that unless original packaging is nitrogen flushed and sealed that almost none of the original packaging is effective. We did some testing with normally zip lock poly-prop bags and found them to be as effective as most of the off the shelf packaging. The freezing in these bags produced better results than sealing the original bags.

    We did find the degree of roast a big determinant of whether or not the freezing was effective. Past second crack the coffee did not like domestic freezing.

    Thanks for the post. Would love to have had your results linked to sensory testing.

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    1. Hey, I did not do a very scientific blind test, but here are my observations: (1) I never had a coffee that tasted oxidized since I used a combination of the freezer (long term), vac sealer and oxypads; (2) I had some amazing coffee that was vac sealed stored in the freezer during a year then sent to me over USPS to Canada; (3) I never drink dark roasts so I can’t talk how the freezer affects them, this comment however surprises me; (4) one thing that the vac seals + oxygen pads do not prevent is degassing of CO2. I see less bubbles during bloom when I brew a coffee that spent more than a month or so in vac sealed bags. It still tastes great however, but may have lost a little bit of aromas. When I just took out a vac sealed pad from the freezer after about 2 months, I noticed that there were still a lot of bubbles (I didn’t try coffee stored longer in the freezer). I’ve heard people mentioning Q graders blind tasting properly frozen coffee and not being able to tell the difference, I can’t remember where I read it though (probably Scott Rao’s books or blog, or on Barista Hustle).

      Liked by 1 person

  7. Thanks for the reply. I would agree that bubbles during bloom are a pre-indicator of flavour, however, it really is just proving that there is CO2 left in the coffee. The main reason we did our test was to try and find an easily recyclable product that did not negatively affect the taste of the coffee. The issue with the vac pack bags is they are three bags in one and you need a special recycler. Have not really found a material that satisfies both easy recycling and 100% prevention of ageing of the coffee. We relied on sensory testing, instead of pure science and that’s why I asked the question. Thanks for the post.

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    1. Yeah I agree. One thing that helps lessen waste is doing long slice-shaped V60 bags, it allows me to remove a bit less of plastic every time I seal it back and this way I can normally reuse the initial ~90g bag for another ~40g after.

      Liked by 1 person

  8. This is a really nice writeup about preserving coffee freshness! I enjoyed reading it.
    I would just like to add if you don’t mind.,,you recommended a dozen minutes temperature equilibration time when taking coffee from the freezer. This is fine for single portion packages. But for taking a 250g bag out of the freezer I would recommend minimum 1 hour equilibration time. The beans are quite bad heat conductors and although the bag might be at room temperature after 10 minutes, the beans inside could still be at the temperature below the dew point.

    Liked by 1 person

    1. That’s possible, I haven’t tested this extensively. How about putting the vac sealed package in warm water for 10 minutes, carefully dry it then open it ? I tried this and it seems to work very well; there was zero condensation on the beans.

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      1. This is what I do very often, when I need to take a coffee bag from the freezer and use it soon. That or putting a bag directly from the freezer on top of the espresso machine for 15 min.

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  9. I have had dubious results with oxygen absorbing packets. Normally, I package 12 oz. of fresh roasted beans in foil-lined Kraft coffee bags with valves. I heat seal the bags immediately and use a Waring kitchen sucker to pull all the air out through the valve. Bags are now hard as a rock. In a few days, they balloon up nicely and have stayed decent for a month or more.

    Lately though I started using oxygen absorbing pads when I first package and seal. Results: (1) the bags don’t balloon up nearly as fast; (2) the coffee seems less fresh tasting. This is anecdotal observation only.

    Could it be that the oxygen absorbing packets are taking something out besides oxygen?

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    1. That surprises me. Maybe blind tasting would be better, e.g. store 2 similar sized vac-sealed packages, one with and one without oxygen absorber. Then freeze them for a few months, take them out at the same time, brew two cups and try to distinguish them blindly. You can use my blog post on the stats of blind tasting to determine whether your result is statistically significant – if you do it I’d be happy to help with that. The reason why this would surprise me is because it’s widely used in preserving dry food, so I would expect it to be known if it hurt flavor. I also did not notice a difference with coffee, but that’s not very conclusive evidence.

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  10. What is the best way to defrost beans? To take it out of the night ? Is it a big difference in time if I defrost 250g of coffee or a dose of 22g? Thanks

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    1. Best way is to let the beans reach room temperature before you break the package seal. Otherwise, lots of humidity will quickly get inside the package and spoil the rest of the beans. Defrost time depends on packaging and package shape. If you use long tubes like me, 250g should be just a tad longer than 22g. I don’t have actual numbers though. The night before is definitely enough; 5 min is definitely not enough unless you run the packaging under warm water (I wouldn’t try hot). Just make sure you dry the package very thoroughly before breaking it open. If you freeze single doses individually, then resealing is not an issue anymore, but grinding cold beans will generate a bit more fines, so it’s still best to let them thaw in their packaging.

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    1. The best is to try it, then take a single bean from the middle of the bag and break it in two, and check if the center still feels cool. As for running water, I do it in the vac sealed package to avoid starting some extraction at the surface of the beans and I don’t want to put completely wet beans in my grinder.

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  11. Who do you think is the ideal way to pack coffee and storing beans from a roaster? Eg vacuum seal zip lock without valve or vacuum seal zip lock with valve and why?or maybe something else? Thanks

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    1. Well that’s a hard question cause you can always get a few % better by using crazy expensive or non environmentally friendly things. I think the best realistic way is relatively small ~250g bags, vac sealed and without a one-way valve. Having a ziplock mechanism is also great for normal users. Basically what Gardelli does ! Otherwise, pressurized CO2 cans would be even better but that’s insane.

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      1. Do these packages without a valve need to “rest” ? because if it packs right after roasting and the coffee is eg for espresso how will i make it decas without exposing it to oxygen if it does not have a valve?

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      2. For filter, no. For espresso, I don’t know but probably. Resting ground coffee for 10 min should be enough, or resting the bag ~5 days after first opening should be enough for espresso.

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  12. Any thoughts on the Fellows Atmos canisters? Their write-up in defense of their product is here: https://fellowproducts.com/how-vacuums-prevent-coffee-staling/. Anecdotally, I haven’t noticed a huge difference since buying one. I’ve also started throwing an oxygen packet into the canister but not noticing that much improvement there, either. I store 12-16 oz of beans, which I use up in about a week. By about day 4 or 5, I already notice a decided reduction in crema in my espresso pulls.

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  13. Any thoughts on the Fellow Atmos canisters? I purchased one and use it for 12-16 oz of beans at a time (along with an oxygen packet thrown in for good measure). I’ve not noticed little/no improvement in bean freshness; the crema in my espresso pulls still appears to be decidedly reduced by about day 4 or so after opening. (Beans arrive by mail, usually at 2-3 days off roast.)

    Fellow’s defense of the product is here: https://fellowproducts.com/how-vacuums-prevent-coffee-staling/

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    1. Yeah I tried them, I also noticed very little difference. It doesn’t increase pressure in any significant way, and the fact you need to open up the whole canister every time you take a dose slowly damages the whole beans. It seems well sealed, so if you add a few oxypads it should be a bit better than most coffee bags, but definitely worse than vac sealing. I also tried freezing beans in it, and they smelled like argon after I took them out, which means the seal isn’t 100%

      Liked by 1 person

      1. Good to know I’m not crazy. I’ll try adding another oxygen pad or two beyond the current one just to see. I’ve also been bugged by the need to open up the entire canister each time. Presumably, re-sealing each time doesn’t undo the oxidation damage effected by the “new” oxygen that rushed in on opening, I take it, b/c its effects are pretty quick?

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      2. Exactly. The effects of oxygen don’t need to be quick; you just replaced it in the jar and sealed it back with plenty of new oxygen. The oxypads are a bit slow, that’s why I’d use more than one in that scenario. They’ll last for a long tome though, until they feel crystallized to the touch.

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      3. Isn’t the idea that you pump that new oxygen back out when resealing the container? Or has the new oxygen ready done its damage by that point?

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      4. The only thing that canister does is push out excess air above the beans. It’s a good start but there’s still plenty of oxygen in between the beans that gets replenished every time you open the canister. So the oxygen has all the time it needs to react, there’s just not as much of it compared to an unfilled regular canister, because the latter has a lot more total air in it.

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      5. Got it, thanks. So point being, the canister is only a very partial solution that leaves enough O2 to oxidize the beans over the course of the week it takes me to get through the bag. So if extra O2 pads don’t do the trick, I need to find a different solution.

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      6. Exactly. A week is a bit short, you might be ok with the canister and oxy pads, but the taste will definitely degrade at some point; try it and you’ll see.

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      7. K, I’ll pack in 3 pads (was using 1) and see. I generally see a huge degradation in crema by day 4 or so, which means ~1/2 of my shots are watery. And I know it’s not technique because as soon as I open a new bag, it’s thick, syrupy pulls again.

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  14. It occurs to me that the loss of crema (CO2) is less about oxidation/staling and more about degassing. It’s strange to me that I see such a dramatic difference between day 3 and day 10 off-roast, but I’ve consistently found that crema is nearly gone about halfway through the week it takes me to use up the beans. Maybe freezing in half-bag 6 oz) portions would do the trick, since the crema is always there for a couple days after opening a (thawed) bag that was frozen.

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    1. Oh yeah as I understand it crema is made of dissolved CO2, so it makes sense that the crema goes away as the beans degas. Keeping beans vac sealed in the freezer should keep crema for a very long time.

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