Lye with no lid

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CatahoulaBubble

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So I made up some lye mixture 2 days ago so I would have it ready when I wanted to make soap this weekend. Once it cooled I put a lid on it and left it on my counter in my workspace. Well my partner was visiting and unknown to me he took the lid off so it's been sitting out for 2 days with no lid. The reason he took the lid off is because he thought it would explode if you left the lid on it. Mr. "I know better than you do" insisted that pre-mixing lye will result in lye exploding. Honestly I'm exasperated and annoyed but what I'm really wanting to know is can I still use this lye mixture even though it hasn't been stored with the lid on? It looks ok although I see a lot of lye lint so I will need to strain that out but is it ok to still use? I hate to waste it.
 

amd

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but what I'm really wanting to know is can I still use this lye mixture even though it hasn't been stored with the lid on? It looks ok although I see a lot of lye lint so I will need to strain that out but is it ok to still use? I hate to waste it.
First, you have my sympathies. I think if your container has a lot of head room, there's no danger of the lye exploding when still hot (and definitely not after it's cooled), I usually put a screw on lid on mine and leave the it very loose (like only turn the lid 1/4 turn to tighten and then tighten fully after it's cooled). You can tell your know it all partner that.

Second, yes you can still use this lye. If you know the container weight (or have another same container that you can use to tare the scale) you'll be able to check the weight (I know you know but I'll say it for other readers, the weight should be the water + lye weight) and add more water to make up the difference. You said you want to strain out the lye lint, so you could pour it into another container and strain at the same time to get your tare point too.
 

shunt2011

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I do the same as amd. I use tall Ziploc food containers for my lye. I just rest the lid on it after mixing and then screw it on tightly once cooled. I actually have 4 containers sitting in my sink since last week waiting for me to make soap. Just do as amd said and you should be fine. Tell your partner hands off.... ha ha
 

CatahoulaBubble

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Thanks, I can weigh it because I have the weight of the container written on the side so I always remember it. All of my soaping bowls/containers I weighed and then wrote on them so in case I forgot what I was weighing out or if my scale shut off in the middle of me getting my oils and such together I would know how much to subtract. I have told my partner hands off my stuff. He doesn't even make soap or know much about making soap beyond watching me cut it. lol
 

DeeAnna

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Actually, I'd pour it all into the soap, lye lint and all. The "lint" is sodium carbonate that was once some of the sodium hydroxide you were going to use to make soap. You want all of that alkali in your soap. The carbonate will react with free fatty acids, so it will make soap too.
 

CatahoulaBubble

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Actually, I'd pour it all into the soap, lye lint and all. The "lint" is sodium carbonate that was once some of the sodium hydroxide you were going to use to make soap. You want all of that alkali in your soap. The carbonate will react with free fatty acids, so it will make soap too.
Oh ok, I was always told to strain out lye lint.
 

cmzaha

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Like DeeAnna mentions I always pour the lint, into my oils if I have made lye solution and let it sit around.
 

DeeAnna

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Oh ok, I was always told to strain out lye lint.
I get why people give that advice, and the world won't end if you do strain it out. I just want people to know it's not a deal breaker if you don't strain out the lye lint.

It's a whole different deal if a person doesn't get the NaOH (or KOH) fully dissolved and pours the lye solution into the fats, solid bits and all, into their fats. That IS a deal breaker. ;)
 

earlene

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Well unless you mixed it in an aluminum container, he has his chemical references crossed (link).

Just to give you more fuel shared experience for the discussion with your know-it-all misinformed partner, feel free to share this:

I have been making master-batch lye solution somewhere around 4 years now, and others here for longer than that. If any of us had had our stored lye solutions explode, you can bet we would have warned others about it and would not be touting it as a useful, time-saving and acceptable practice!

I keep my master batch lye solution (50% water to 50% NaOH as is quite common for master-batch lye) in a tightly-lidded PP (#5) container (once it has cooled, of course) for extended periods of time. When I first make the solution, I allow it to cool in the mixing vessel (also PP #5), with the lid in place. It is not an air-tight lid, but I definitely keep the lid on to prevent the escape of evaporate into the room; any evaporate falls back into the container from the inside surface of the lid. Once the outer side walls of the container are cool to the touch, I fill the lye storage bottle(s) with a bit of clearance from the top, and tightly screw the safety lids to ensure they will not leak if knocked over. The lid is one of those child-proof lids that you have to push down on while turning it in order to remove it. They are absolutely leak proof because I have tested them to make sure. They are then stored inside another larger HDPE container standing upright to ensure that if one of them ever develops a leak (and they never have as yet) it will be contained. Not once has any of them ever spontaneously erupted, nor have they ever even expanded. They are clearly labeled, weights recorded and all that good stuff.

Over time as I use portions of the 50% solution, the bottle becomes less full with solution and has more air with which to interact, and the solution can become slightly more viscous, which can also be influenced by lower temperatures. As the level of liquid diminishes with use, and seems to be thicker, I shake the bottle prior to opening to ensure it is well mixed. This has never caused any eruptions, explosions or even bottle expansions or tops popping off.

Maybe the partner would like to take a look at this table or the article from which it comes:
1590239124908.png

The above table is from this site, which discusses safe storage of liquid sodium hydroxide. You can read more about how viscosity factors into the equation when storing lye solution long term in the sited article.

And just to let you know how non-explosive it is, I have transported master-batch lye in my car while driving from my home to elsewhere (for off-site soap making.) There has never been an issue with exploding lye solution in my car. If there had been, you can bet I would either not be here to talk about it, or I would have warned y'all about it.

They are not bottles of nitroglycerin, for heaven's sake and this is not some Hollywood Western where I'm riding around over a rocky road in a buckboard wagon with a wooden boxful of nitro bouncing around in the back.

Edited to correct error of type of plastic I use for storage.
 
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SPowers

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I do the same as amd. I use tall Ziploc food containers for my lye. I just rest the lid on it after mixing and then screw it on tightly once cooled. I actually have 4 containers sitting in my sink since last week waiting for me to make soap. Just do as amd said and you should be fine. Tell your partner hands off.... ha ha
The zip lock containers are the right plastic to hold the lye/water? I'm still getting over my fear of lye and have visions of it eating through the plastic and creating a terrible mess.
 

earlene

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The zip lock containers are the right plastic to hold the lye/water? I'm still getting over my fear of lye and have visions of it eating through the plastic and creating a terrible mess.
Ziploc does not only make baggies, they make rigid-sided plastic containers as well.
According to the Ziploc website all of their products are made with polypropylene.
As long as it's got a #2 or #5 recycle codes, it's fine for lye solution. Polypropylene's recycle code is #5.

When traveling, I've used the same Ziploc screw-top container that Shari uses for mixing lye and they work just fine.
 

DeeAnna

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I guess I've never seen the screw-top containers by Ziploc, so I was puzzled too. I've only seen Ziploc lightweight containers with tops that snap on and their zipper bags.

I'd be really reluctant to use a snap-top container for lye storage and I'd never use a bag. But a screw-top container made of polypropylene or high density polyethylene would be good for lye storage. I'll have to keep an eye out for the Ziploc containers like this. Nice tip!
 

SPowers

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Ziploc does not only make baggies, they make rigid-sided plastic containers as well.
According to the Ziploc website all of their products are made with polypropylene.
As long as it's got a #2 or #5 recycle codes, it's fine for lye solution. Polypropylene's recycle code is #5.

When traveling, I've used the same Ziploc screw-top container that Shari uses for mixing lye and they work just fine.
I have the ziplock containers for storing soup... good to know I can use them for lye/water as I wanted to start making it up in advance. I'll look for the recycle code on mine. Thanks so much!
 

dippy

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Are the ziplock containers the same type as the lock&lock in the UK? They are sturdy plastic and have clip down sides on the lid.

They were the ones I intended on using - but I thought any plastic tub with a lid would be ok.
 

SPowers

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I would suggest looking at the bottom for the recycle number - either 2 or 5 is good for the lye/water. I checked my Ziplock's and they were properly numbered. Also I was in the dollar store today and they had a different one with screw-on lid but no number on the bottom so I wouldn't use it.
 

dippy

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Oh I can't find either of those numbers on my lock & lock containers! I will have a look and see what other options I have.

Does this apply also to mixing the lye or can you use any sturdy plastic tub to mix the lye if you are using it as soon as it has cooled?
 

dippy

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I have just found my answer on the Lock&Lock. Although it doesn't have a 5 on the tub it is made out of polypropylene according to the company website so its good to use.
 

SPowers

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Good to hear... I use a pyrex measuring cup for my lye/water mixing so can't answer your other question.
 

dippy

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Thanks SPowers - I have just looked at the tubs I intended on using for mixing and they have a 5 on the bottom so it's all good.
 
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