Bad smell when opening frozen coffee bag

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mixespresso

#1: Post by mixespresso »

Hi,

After buying it from the roaster, I immediately froze a 250g bag of coffee. So, I did not open it at all and it was fully airtight, so it could not get contamination by other potential freezer smells.
When I opened it after a few weeks in the freezer, I was not impressed by the strong smell coming from the bag.
Could it be that the bag itself was not suitable for freezing? (I know this roaster very well, and they make great coffee)

Thanks

Pressino

#2: Post by Pressino »

Was it vacuum packed? I try not to freeze beans that are loose packed in a bag containing air to avoid condensation. Was it a musty smell? Could have been some bad beans in the roast. Try letting it air out to see if the smell goes away and then try brewing some. :(

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JohnB.
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#3: Post by JohnB. »

Was it a valve bag? If so did you tape over the valve?
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yakster
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#4: Post by yakster »

What coffee was it?

Possibly related, but not sure it would explain a bad smell: Coffees that don't freeze well
-Chris

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mixespresso (original poster)

#5: Post by mixespresso (original poster) » replying to yakster »

Thanks for the thread link. Very interesting

It is a natural brazilian
I had it from the same roaster bf and I was happy

mixespresso (original poster)

#6: Post by mixespresso (original poster) »

JohnB. wrote:Was it a valve bag? If so did you tape over the valve?
Yes, it is a valve bag. I did not tape it. I did not know that that is what you are supposed to so as I thought the valve was more for expelling air?

mixespresso (original poster)

#7: Post by mixespresso (original poster) »

Pressino wrote:Was it vacuum packed? I try not to freeze beans that are loose packed in a bag containing air to avoid condensation. Was it a musty smell? Could have been some bad beans in the roast. Try letting it air out to see if the smell goes away and then try brewing some. :(
Not fully vacuumed, but the bag comes rolled in with little air and a valve.
When I opened the smell was "not pleasantly" intense. The intense smell did go away but the beans have very little aroma which confused me.
I have always frozen using plastic bags, so I wondered if the compostable bags that the coffee came with are suitable for freezing?

I think next time, I will open the bag before freezing to check smell and aroma. Then freezing for a few weeks and check again to see if I can notice any change

Thanks

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JohnB.
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#8: Post by JohnB. »

mixespresso wrote:Yes, it is a valve bag. I did not tape it. I did not know that that is what you are supposed to so as I thought the valve was more for expelling air?
The valve can stick in the open position in a freezer which will allow freezer odors & moisture into the bag.
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mixespresso (original poster)

#9: Post by mixespresso (original poster) » replying to JohnB. »

oh, great to know. Thanks!

jpender

#10: Post by jpender »

One coffee bag valve manufacturer I've seen lists the operating temperature range as down to 10°C (50°F). Another possibility is that the compostable bag material your bag is made out of provides a poor oxygen barrier.

When I freeze unopened bags I tape the valve and also stick the bag in a ziplock. Then I either put a rubber band around it or wedge it in between other items in the freezer. Ziplock bags are not really airtight but they restrict airflow. Combined with the bag I find it does a good job.

I've measured moisture content of beans stored in an opened bag rolled up inside a compressed ziplock and it stayed constant after months. Opened bags with just a rubber band around them (no ziplock) gained moisture in the freezer.