freeze / thaw cycles will eventually kill seeds.
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I use a dedicated mini-fridge.
Anything that you intend on touching with any regularity keep in the fridge.
Anything that you plan to archive or not touch for a long time put in the freezer.
I pack all chilled seeds with dry rice grains as a desiccant. It is easy to dry out in the oven first.
Anything that is not going to be touched goes into Tupperware, then ziplock, and then vacuum sealed.
I never save pollen but there are guides others use to do that as well. (double glass, puffed rice, flour, seal, etc)
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Thats what I was thinking of doing, I have one laying around so I might as well ya know.
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Are there any concerns in regards to frost-free fridges vs regular fridges?
I believe the frost-free units, have lower relative humidity but IDK if that might be a plus or minus.
Cheers
G
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I figure as long as its sealed and you have a desiccant in there it shouldnt matter?
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I’m using double zip-lock bags, descant and original packaging so I should be good but there is something bothering me about frost-free…
G
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Both work. Rob Clarke believes the fridge is the way to go. My friend Brother Mendel believes that fresh seeds should be winterized by freezing for 48 hours and then storing in the fridge. I freeze immediately in plastic zip bags in Tupperware and have 90% viable beans that are over 25 years old. I try to minimize time out of freezer when I’m rooting around but otherwise there’s no other special protocols involved. peace -b420
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Actually the only desicant I use is in the package the seeds are in, anything more is over kill.
Been storing this way for well over 40 years but what do I know.
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I’ve wondered about that for some time, do the desiccant packs over dry seeds?
Do they have a certain equilibrium humidity or will they dry down to 0%? I’m guessing towards 0%.
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Cracking 20 plus year old seeds that I put up, with 95% germ rates.
I’d say I got it down
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You could determine the equilibrium and rate constants at which it transfers (too much Pchem) but the short is yes, its going to absorb as much available moisture in the air due to silica being hygroscopic. I use it as a color indicator to determine if my jars are properly sealed and to keep it dry. Realistically if you were to have a desiccator that was flame dried on a Schlenk line and flooded with argon itd be an ideal storage container in a cool condition as itd be considered dry and in inert atmosphere at that point.
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Which, I’d assume, would be a bad thing for seeds (going to zero humidity). They do need to retain a certain amount moisture in storage. At least, from my understanding.
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So when you guys pull out a pack to pop some beans from the freezer, do you let them thaw before putting them in a towel / shot glass full of water OR do you just throw em in and let em start germinating frozen and all?
@Northern_Loki I assume that some moisture is good as well but finding that sweet spot I assume would be difficult. Perhaps freezing them is what causes the water inside the seed currently to remain in place and a similar concept with the fridge due to the lower temps. But with le chatelier’s principle; id put money down that eventually if you left em in desiccant in the freezer itd eventually take the RH down to 0. Maybe that’s the next big thing for the weed business; selling seed storage units that keep em at perfect conditions until use.
- BD
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Maybe, but not too much! 
I stored my seeds in small plastic containers inside a locked tapper in the fridge, and this is what I found:
Now they are in vials inside of small labelled and zipped plastic bags on a hermetic jar with some rice inside … 
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How in the world did that happen? 100% humidity 
New germination technique. Cold brewed seeds.
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They may sit for a while til I get around to throwing them in water or introduced directly, makes no diff.
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I’m still asking myself! 
Happened in other boxes also, ritual suicide? Humidity is around 60% here but inside a fridge and hermetically closed box and tupper goes against any logic … 
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Oh. I think you’ve hit the dew point. That’s a fairly high humidity. If the temperature outside is fairly high relative to the refrigerator, once you cool it down the water vapor condenses within the sealed containers. Though, that’s a lot of moisture for such a small container 
Perhaps, cool it down with the lid open in the refrigerator and then later close them while they’re cool.
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Here’s some data points - ‘freshly stolen from the Interwebs’
Properties of Adsorbents
| Property | Molecular Sieve | Silica Gel | Montmorillonite Clay | CaO | CaSO4 |
|---|---|---|---|---|---|
| Adsorptive Capacity at low H20 Concentrations | Excellent | Poor | Fair | Excellent | Good |
| Rate of Adsorption | Excellent | Good | Good | Poor | Good |
| Capacity for Water @77° F, 40% RH | High | High | Medium | High | Low |
| Separation by Molecular Sizes | Yes | No | No | No | No |
| Adsorptive Capacity at Elevated Temperatures | Excellent | Poor | Poor | Good | Good |
Figure 1:
Adsorption Rate (H2O)
of Various Adsorbents
Basically, the common silica gel is poor at sucking up low H2O levels (it will pull down to 10% (ish) assuming it is fresh, but if you really want to suck up most of the residual few percent you need the less common molecular sieve. That will get you under 5%., which is what you want for freezing.
Cheers
G
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One would think that initially but when you consider a seed is designed to fall off and survive all through winter on the ground it makes sense that a seed would last longer in winter.
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