Oxygen Absorbers & Laminated Storage Bags

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Bok
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Sun May 24, 2020 4:39 am

twno1 wrote:
Sun May 24, 2020 4:05 am
The re-sealable alum/PET bags I bought online (same as the ones that Thes-Du-Japon uses) seem to "leak" air when I squeeze them.
If I put one filled with air under water, there are no bubbles in the water. However, if I squeeze the sealed bag under water, air bubbles will emerge from the sealed bag. Do you all think this would be a problem for long term (1 year) storage in terms of freshness?
One year I’d consider short term storage. Should be fine in my opinion. For long term storage people in Taiwan do advise against them as they seem to leak out smell in the long term.
twno1
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Sun May 24, 2020 9:34 am

Bok wrote:
Sun May 24, 2020 4:39 am
twno1 wrote:
Sun May 24, 2020 4:05 am
The re-sealable alum/PET bags I bought online (same as the ones that Thes-Du-Japon uses) seem to "leak" air when I squeeze them.
If I put one filled with air under water, there are no bubbles in the water. However, if I squeeze the sealed bag under water, air bubbles will emerge from the sealed bag. Do you all think this would be a problem for long term (1 year) storage in terms of freshness?
One year I’d consider short term storage. Should be fine in my opinion. For long term storage people in Taiwan do advise against them as they seem to leak out smell in the long term.
Can you elaborate on leaking out smell in the long term? I tried squeezing one of the bags again underwater after heat sealing the top (rather than only using the ziplock) and there were no bubbles that came out until I squeezed hard enough to pop the heat seal.
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Bok
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Sun May 24, 2020 9:39 am

I’m not sure, but several tea merchants and tea friends were very insistent on removing them once the original package had been opened. And roasted or higher oxidised teas never have one.
twno1
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Sun May 24, 2020 10:20 am

Bok wrote:
Sun May 24, 2020 9:39 am
I’m not sure, but several tea merchants and tea friends were very insistent on removing them once the original package had been opened. And roasted or higher oxidised teas never have one.
removing what?
The merchant that sold me lightly roasted lishan gaoshan told me to store the tea in the original package with the sliding bag clip they provided.
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Bok
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Sun May 24, 2020 11:09 pm

twno1 wrote:
Sun May 24, 2020 10:20 am
removing what?
The oxygen absorbers.
twno1
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Mon May 25, 2020 4:30 am

Bok wrote:
Sun May 24, 2020 11:09 pm
twno1 wrote:
Sun May 24, 2020 10:20 am
removing what?
The oxygen absorbers.
Interesting...
If I am repackaging 100g of tea into two 50g packs, do you think I should use an oxygen absorber in the one that I do not plan to drink yet? It would ideally have most of its air squeezed out manually prior to adding an oxygen absorber and heat sealing the top.
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Mon May 25, 2020 4:36 am

twno1 wrote:
Mon May 25, 2020 4:30 am
Bok wrote:
Sun May 24, 2020 11:09 pm
twno1 wrote:
Sun May 24, 2020 10:20 am
removing what?
The oxygen absorbers.
Interesting...
If I am repackaging 100g of tea into two 50g packs, do you think I should use an oxygen absorber in the one that I do not plan to drink yet? It would ideally have most of its air squeezed out manually prior to adding an oxygen absorber and heat sealing the top.
I think it matters little if you don't have a machine that sucks out the oxygen. Most of its air out is not enough even with the oxygen absorber, at least with greener high mountain.
twno1
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Mon May 25, 2020 4:57 am

Bok wrote:
Mon May 25, 2020 4:36 am
I think it matters little if you don't have a machine that sucks out the oxygen. Most of its air out is not enough even with the oxygen absorber, at least with greener high mountain.
Well the oxygen absorber I am using is rated for 100cc of oxygen, or 500cc of air. The sealable bags I'm using are about 200cc in size without any tea in it.
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Bok
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Mon May 25, 2020 5:05 am

Is it really worth the hassle for only 100g of tea after all, no? If I open a bag of teas that loose freshness quickly, I just finish it in 1-2 weeks. But that's just me.
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Mon May 25, 2020 6:41 am

Bok wrote:
Mon May 25, 2020 5:05 am
Is it really worth the hassle for only 100g of tea after all, no? If I open a bag of teas that loose freshness quickly, I just finish it in 1-2 weeks. But that's just me.
There are some green teas for which I definitely feel there is a clear degradation within a few days from opening, and for which reducing that degradation would be worth the hassle of dropping a couple of oxygen absorbers, even if I intend to finish the bag within a couple of weeks. Of course, that is only useful if it actually preserves the magic of the tea a bit longer, which for now is a hypothesis to be tested rather than a certainty.
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Mon May 25, 2020 7:00 am

A friend of mine who sells Japanese teas swears on those Kaikado caddies for Sencha. Said they’re terrible for all teas, except for those.
twno1
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Wed May 27, 2020 1:22 am

Bok wrote:
Mon May 25, 2020 5:05 am
Is it really worth the hassle for only 100g of tea after all, no? If I open a bag of teas that loose freshness quickly, I just finish it in 1-2 weeks. But that's just me.
I like to have 4-5 teas open at once so I'm not drinking the same thing every day...
Splitting a 100g bag into 2x50g bags helps a bit in the sense that I wouldn't be super rushed to finish

Anyways, I split a 100g bag of tea into 2 50g bags using a laminated storage bag and added an oxygen absorber + silica gel package. I don't really know much about oxygen absorbers but the ones I bought said they absorbed 100cc of pure oxygen (500cc of air) over a period of 4-5 hours and that it was OK to use it with silica gel.
I manually squeezed as much air out as I could but only heat sealed one of the bags (non heat sealed one is intended for everyday use). After a few hours, the heat sealed one "crumbled up" and looked like it was vacuum packaged, so I assume that the oxygen absorber did its job. The non heat sealed one still had some give to it so I assume that the ziplock seal on the bag doesn't make it 100% airtight.
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Tor
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Wed May 27, 2020 1:38 am

twno1 wrote:
Wed May 27, 2020 1:22 am

Anyways, I split a 100g bag of tea into 2 50g bags using a laminated storage bag and added an oxygen absorber + silica gel package. I don't really know much about oxygen absorbers but the ones I bought said they absorbed 100cc of pure oxygen (500cc of air) over a period of 4-5 hours and that it was OK to use it with silica gel.
I manually squeezed as much air out as I could but only heat sealed one of the bags (non heat sealed one is intended for everyday use). After a few hours, the heat sealed one "crumbled up" and looked like it was vacuum packaged, so I assume that the oxygen absorber did its job. The non heat sealed one still had some give to it so I assume that the ziplock seal on the bag doesn't make it 100% airtight.
The O2 absorber and silica gel are not supposed to be used together as the absorber needs some humidity to work. I don’t know why your bag was crumbled up, but when using absorber alone the volume inisde the bag shouldn’t change.
twno1
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Wed May 27, 2020 5:59 am

Tor wrote:
Wed May 27, 2020 1:38 am
The O2 absorber and silica gel are not supposed to be used together as the absorber needs some humidity to work. I don’t know why your bag was crumbled up, but when using absorber alone the volume inisde the bag shouldn’t change.
The ones I bought are specifically designed to be used in low humidity uses like for tea and coffee. It's explicitly said that it can be used with a dehumidifier.
Using an absorber should in theory decrease the volume by ~20% as oxygen makes up 20% of air, no?
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Wed May 27, 2020 6:54 am

twno1 wrote:
Wed May 27, 2020 5:59 am
Tor wrote:
Wed May 27, 2020 1:38 am
The O2 absorber and silica gel are not supposed to be used together as the absorber needs some humidity to work. I don’t know why your bag was crumbled up, but when using absorber alone the volume inisde the bag shouldn’t change.
The ones I bought are specifically designed to be used in low humidity uses like for tea and coffee. It's explicitly said that it can be used with a dehumidifier.
Using an absorber should in theory decrease the volume by ~20% as oxygen makes up 20% of air, no?
I stand corrected. You’re right; the volume will be reduced. I didn’t notice that as I never vacuum my bag when I used an absorber.
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