I may or may not be accused of ordering way too much green beans at one time 
What is the best way that you’ve found to store green beans? Also - to roast the beans at their freshest - what would be the time that you wouldn’t want to go past? I have some really great Ethiopian beans but after maybe 9 months I don’t smell or taste that nice blueberry flavor anymore. Lesson learned. Once I get through these batches I’ll order less to maintain the freshness. Hope all is well with my fellow roasters!
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I’ve heard that freezing in vacuum sealed bags works well (years). I stored some that way once, they were still good after a year, but it wasn’t a very scientific comparison.
Thread on another coffee site: Vacuum sealing and freezing green coffee - Page 3
Remember - a particular variety coffee beans is basically harvested once a year. It prolly doesn’t matter if you store them at your house, the retailer stores them at his shop, the distributor stores them at his warehouse or the grower/coop stores them wherever. Certainly, no particular care other than protection from weather is taken in storing the beans in the supply chain. They’re put in a big burlap bag and stacked up somewhere.
Gray
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I suspect the main concern with storing beans for a long time is loss of moisture. So to deal with that I use a moisture meter designed specifically for coffee. I use an earlier generation of the linked meter which is also labeled AgraTronix. The installed s/w on my old version is a pain to use but it gets the job done and is fairly repeatable.
With moisture loss in mind, I’ve been using plastic storage bags for 20 years but they are definitely not the perfect answer. The single wall plastic bag that suppliers use seem to still allow moisture loss during storage (the bags are permeable) but at a slower rate. More recently I’ve been ordering larger quantities (25# or 50#) delivered in GrainPro (double wall) bags. When I start using the greens I shift the greens to storage tubs which hold about 7# each. The tubs have a thicker wall than the bags and have a rubber(y) seal.
Works for me but of course YMMV.
Bruce
Edit- there are a lot of moisture meters available. The linked meter above is specifically for coffee. That said I wouldn’t be surprised if the one for grain weren’t very similar.
I’m with Bruce on this. I bought a moisture meter that has a green bean coffee mode and is easy to sue and is around $154.
I change out the bags that the coffee was shipped in for Grainpro bags to help control the moisture.
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Thank you for all the responses. I definitely have to look into better storage. I do have it for some beans but the thin plastic definitely isn’t going to help for long. To everyone that uses a moisture detector have you found it improves your roasting? Does it also tell if a bean is too low in moisture and has to be thrown out? Trying to determine if it’s worth the price!
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I understand everyone’s concerns here, but have you seen the containers in which the coffee ships? And it stays on sea for months. Depending where you are, the minimum is 3-4 months for you to get your hands on your coffee. Usually this minimum is 9 months, but let’s say you’re doing business directly with the farms and they send it to your storage directly, we’re talking about quantities that cannot be moved the same day. Consider that the importer is storing their coffees in large warehouses. Since we were talking about SM, please watch this video and tell me do you really think that those are better conditions than your storage room.
The Annex - Where We Store Most Of Our Coffee - YouTube
Also, can you imagine all this coffee, and keep in mind that there are who knows how many of these warehouses, is consumed that quickly that it always arrives to us at 4-6 months after it’s packed at origin. After containers, warehouses and whatnot, we think that putting it into a bag or freezer will somehow erase a year of that. All this was said in short by gfh65wi. The only sensible thing to do is what bab and billc are suggesting. But that’s just for you so you can act accordingly during your roast. It doesn’t mean that the coffee is bad if it lost a bit of moisture, which it shouldn’t if stored at ambient temp and humidity, it just means you need to dial the temperature down a bit and you’ll end up with great coffee all the same. All in all, the green coffee can be and is stored for years.
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I haven’t thrown out beans because they were too dry. Mostly I use the moisture meter to try to gauge when yellow phase and first crack will occur.
I am very nerdy, and enjoy exploring all the variables.
I think that one of the big differences between what @braca19452f9m is describing about the wharehouses, shipping containers and how long the beans are stacked is: with all of those bags touching each other and no air flow between them, they will experience very little moisture loss. However if you were to take a 5 pound cloth bag of green beans and put them on a shelf in a dry climate, I would expect those beans to dry out over time, depending on the local average humidity.
I also like the grainpro bags because they should help to keep the “aromatics” of the beans from co-mingling with other beans. When I open a grainpro bag of a dry processed, natural bean, I am instantly hit with the fruity aroma of the beans.
These are my experiences. YMMV
Whatever you put in a dry climate, in whatever way you want, it will lose moisture. If you put a coffee warehouse in a 10-20% humidity environment, you won’t be able to store them for extended periods of time, however much you stack them. Then there are the bags on top that keep up with the others, not because they’re tucked in, but because they’re stored in good environmental conditions. It would take more time for a warehouse than your example of a 5 pound cloth bag, but it would get there sooner rather than later. This is also valid for the end user. If you live in Arizona and just leave your beans in some room, the results won’t be optimal. Same goes, in a different direction, in very humid places. If you live somwhere where avg humidity is 50-60%, there’s no need to worry too much about the green beans. Just keep them in a dark place. As for grainpro bags, I agree. Although, I must say, I haven’t had any problems with the bags that came without it. But surely they are much better because plastic doesn’t let air through. Some years ago, I was buying retail beans in 1kg packaging, now I buy full bags. The 1kg packaging was net bags, so all the air you want. I’d just put them in a jute bag and put that in a dark isolated place. Nothing much happened for a year, and that’s without taking into account how much time they’ve spent between the harvest and getting to me. If people here are worried about small quantities, just take some of those vacuum sealable bags, keep it out of the sun and you’ll be fine.
FWIW - I am in MA and our humidity fluctuates with the seasons. My green beans are stored in Ecotact bags (same brand SM uses to ship 20lbs of beans - I purchased mine directly from the manufacturer in India) and then in a large plastic tote bin with a lid, and that lives in my (walkout) basement. My basement is temperature controlled as it is a finished basement (and my wine is also down there).
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I think, perhaps the most important thing is to be cognizant of the harvest year of the beans you buy, and perhaps what time of year that particular variety of bean is harvested. Then you have a gauge of how old your beans are.
If you decide that year old beans is as old as you want to deal with (and whatever you buy around harvest time is likely to already be a year old) then, if you want to have these beans around a lot longer, it may make sense to go to more extraordinary steps to keep them fresh - double bagging in plastic, cooler environment etc.
Elsewise, it probably doesn’t make much sense to go out of your way.
Personally, I can’t keep coffee around long enough for it to make any difference!
-Gray
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I, too, use the Ecotec bags that SM’s now sells. But for years I just kept my green in small burlap sacks. Of course, I am lucky enough to live in Houston, so (lack of) humidity was never a problem. I buy two or three five pound orders at a time, and roast about a pound a week, so there is a consistent, but slow, turnover.
A friend of mine visited Hawaii years ago and came back with some green Kona in a vacuum sealed bag. He asked me to keep it for him as he was going overseas for a year. When he got back is asked me to roast some of it. I opened the bag, and it was one solid brick of mold. It smelled so bad I didn’t even put it in my compost bin. So there is a risk of trying to store green too long
Yes - if the moisture level is basically too high - high enough to support mold growth - then storing in a sealed container just makes the problem worse.
For most food stuffs (including coffee) the target moisture content is 10%-12% to prevent mold (and other beasties) growth in storage.
-Gray
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@bilic Hello. I was looking at that same meter but as I recall, the detection range for coffee beans was stated to be 10-13%. Does it tell you when you are above or below that rang and if so, by how much? Thanks!
It just gives a direct reading: For example: 11.5%.
The specifications say the it will measure down to 10%. I have never gotten beans that measured that low. I should put some beans in a dehydrator and measure them after drying them.
I have never tried to measure the moisture after roasting.
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Several on-line sources indicate that the ICO and SCAA standards call for a moisture content of 9% to 12% for green coffee beans. Moisture content higher than this risks the development of mold or other microbes.
Moisture content lower than this will affect the roasting profile, which would need to be compensated for.
Producers likely hug the 12% mark since it costs money to reduce moisture below that. Coffee at the low end of the standard or lower is likely last year’s crop.
Bruce and billc,
Have you independently verified the accuracy of your relatively inexpensive moisture meters?
So much is claimed on Amazon and frequently so little delivered!
-Gray
And they can get more money for the beans as they are selling by the kilo/pound.
I don’t have any way to verify the accuracy of this meter. I use it to see the variability between batches of beans and see how it affects that roasting paramaters on the Bullet and to check to see if older beans are changing their moisture level over time.
So far, everything that I have measured has been between 10 and 12%.
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Like Bill I have no calibration standard. I haven’t worried about it simply because my principal use is to track the moisture content (it’s always going down). Without calibration that’s about as much as I can do since the primary measurement is suspect. But month-to-month comparisons ought to be meaningful even if the absolute value can’t be validated.
Bruce