Humidity Control: DIY Salt Packs

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Psyck
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Mon Jan 15, 2018 3:29 am

VoirenTea wrote:
Sat Jan 13, 2018 11:46 am
I am interested in the answer! I could buy Tyvek in A4 sheets, or rolls of fabric (or, amusingly, whole-body coveralls) for a lot less than a minimum order of envelopes which seem to be much less common here, but if I can use fabric I already have...

It looks like Tyvek is breathable, but less so than uncoated nylon or most raincoats.
I think any thin breathable fabric should work as a substitute to Tyvek for this purpose. It should be trivial to experiment and confirm this. Over time, it is likely that salt crystals will deposit on the material used - which would require periodic cleaning.
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pedant
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Mon Feb 26, 2018 3:48 pm

yes, any breathable fabric will work for preventing stuff from falling into your salt pack.
however, normal fabric will provide much less splash resistance if the jar gets bumped.
tyvek is fairly waterproof. if you accidentally knock the jar over, i don't think much if any liquid will leak out -- especially if you notice and pick it up right away.
Mchrlund1 wrote:
Fri Jan 05, 2018 9:40 am
So I finally got around to setting up the experiment. As the mason jars I got were a bit bigger, I thought why not just up the amount of mixture. 200g water heated and mixed with 34g sugar until dissolved, then added 140g of unrefined sea salt and mixed for a bit.
looking again at your picture, i'm noticing your jar has a layer of scum. i'm thinking that's from using unrefined sea salt.
did it go away?
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pedant
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Mon Feb 26, 2018 11:20 pm

i actually just made a new one today scaled up 4x (400mL water)

i would like to make a cutout in the tupperware lid and glue in a piece of tyvek with silicone sealant, but i don't have any right now.
so for now there is no lid. just some rubberbands to prevent a cake from falling in or something. the paper towel probably doesn't do much, but it might block some smaller debris. obviously, i have to be careful not to bump it, but it should be fine. the tupperware has tall sides, and the rubberbands give it a non-slip base.

Image

edit: don't use rubberbands. they're a little smelly
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pedant
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Wed Feb 28, 2018 3:43 pm

originally brought up by Microshrimp, some brands of salt have an odor. i believe that this smell is adsorbed onto the crystals and comes from packaging, transportation, or storage. it's most apparent while the salt solution is still hot, but you can still smell it after it cools down.

to me, it smells somehow salty (reminiscent of gargling with saline). Atlas described the smell as powdery.

i looked at a couple of types of salt i have on hand right now: Morton salt (non-iodized) and Morton natural sea salt (non-iodized).

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Image

for each one, i mixed 20g salt + 30g 65°C (150°F) water in a small drinking glass.

here are notes on how they smelled over time:

Morton salt (non-iodized):
  • day 1, just after mixing (still hot): quite smelly (relative intensity: 10)
  • day 1, after cooling: less smelly (RI: 8)
  • day 2: some improvement (RI: 5)
  • day 3: significantly dissipated (RI: 1-2)
  • day 3, after adding 15g water, heating in the microwave, and stirring: odor has returned slightly (RI: 2-3)
Morton natural sea salt (non-iodized):
  • day 1, just after mixing (still hot): smelly (relative intensity: 7)
  • day 1, after cooling: some improvement (RI: 5)
  • day 2: maybe a bit better (RI: 4)
  • day 3: smell significantly dissipated, seems fine to use (RI: 0)
  • day 3, after adding 15g water, heating in the microwave, and stirring: about the same (RI: 0-1)
i think it's important to smell your salt pack before putting it in the pumidor.
if it's smelly, it will probably be fine to use after airing it out for 3-7 days (give it a daily stir).
if that doesn't work, try another brand.
Mchrlund1
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Mon Oct 08, 2018 12:43 pm

pedant wrote:
Mon Feb 26, 2018 3:48 pm
yes, any breathable fabric will work for preventing stuff from falling into your salt pack.
however, normal fabric will provide much less splash resistance if the jar gets bumped.
tyvek is fairly waterproof. if you accidentally knock the jar over, i don't think much if any liquid will leak out -- especially if you notice and pick it up right away.
Mchrlund1 wrote:
Fri Jan 05, 2018 9:40 am
So I finally got around to setting up the experiment. As the mason jars I got were a bit bigger, I thought why not just up the amount of mixture. 200g water heated and mixed with 34g sugar until dissolved, then added 140g of unrefined sea salt and mixed for a bit.
looking again at your picture, i'm noticing your jar has a layer of scum. i'm thinking that's from using unrefined sea salt.
did it go away?
So sorry, never got back to you on this!
I think it was mostly undissolved salt and a bit of foam from the hot water+sugar/salt solution. I think it went away, didn’t notice anything weird about it (and I work with food, so I have a bit of a ‘nose’ for weird food related things).

What I can say, though, is that this method has worked wonders for my teas. I live in a house that gets quite dry, especially during the winter months (basically meaning October-March here) due to heaters + wood stove. Last winter I began to notice some drying out and muted taste in many of my puerh teas, and it did take a few months before the new ‘pumidors’ were at a steady rh of about 70. One is still resting a little lower at 65-67, and one is actually at 79-85 (nice for ‘seasoning’!), but they’re all above 65 and - most impotantly - my teas have come back to life and are tasting beautiful!

I think this might have saved the next 20 years worth of tea 🍵 - very grateful!!
Last edited by Mchrlund1 on Mon Oct 08, 2018 12:48 pm, edited 1 time in total.
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pedant
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Mon Oct 15, 2018 3:19 am

Mchrlund1 wrote:
Mon Oct 08, 2018 12:43 pm
What I can say, though, is that this method has worked wonders for my teas. I live in a house that gets quite dry, especially during the winter months (basically meaning October-March here) due to heaters + wood stove. Last winter I began to notice some drying out and muted taste in many of my puerh teas, and it did take a few months before the new ‘pumidors’ were at a steady rh of about 70. One is still resting a little lower at 65-67, and one is actually at 79-85 (nice for ‘seasoning’!), but they’re all above 65 and - most impotantly - my teas have come back to life and are tasting beautiful!

I think this might have saved the next 20 years worth of tea 🍵 - very grateful!!
do you mean 79-85°F or %RH? be wouldn't go above RH ~70% due to mold risk.
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pedant
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Mon Oct 15, 2018 3:21 am

someone was asking me how well tyvek resists leakage in case a salt pack gets knocked over.

tonight, i tested it out and saw no signs of leakage after inverting one for an hour. i wouldn't bet my collection on it, but it does seem pretty safe.
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Ouronok
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Thu Nov 29, 2018 10:30 am

First of all, thanks Pedant for compiling this wonderful tutorial which I followed when I needed to build my first home pumidor a while ago.

I wanted to share my experience and my parameters in order to help anyone interested.

First of all, I've used distilled water, kosher salt and a bit of regular white sugar, scalled down the recipe and put the solution in a little crystal jar. Made two of these jars in order to put them in the sheng and shu pumidors.

Have to search for the capacity of the plastic boxes, but let's say 12l for the moment.

The load of the sheng pumidor is comprehended of a tuocha and some bags with parts of cakes, not really big but almost takes the whole space of the box adding the jar. In this case the salt has remained saturated and in little crystals at the bottom opening it almost every day.

In the case of the shu unfortunately only have a cake for the same size of the box. Crystals have grown quite big, almost to float and I only open it once a week or two.

Now talking about the humidity of each one I haven't been able to fix it. The sheng goes from 62 to 72 aprox and the shu stays from 68 to 70. Asides that it has stayed rather stable in the range of good humidity to store the puer so I'm not worried having worked for that long, but I will need to remake the shu jar to avoid that crystalization.
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