Lye strength weaken over time

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rosche

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So...I'm currently make quite a lot of small batches of soap. Since I make a lot, therefore I often open my lye container. What I'm concern is somewhat the lye 'feel' not as strong as like the first time I use it.

I mean, when I first use the lye, the lye dissolve very quickly and have hissing sound. After a couple of batches, the lye dissolve not as fast as the first time. Also, it doesn't really hiss.

The few early batches get to trace quite fast, but recently become slower.

Does it mean my lye weaken? Because whenever I open it, it will contact with the air and become...somewhat soggy and weak lye?

And if so, will it ruined the recipe? I mean, if I have to use 20 gr of lye to have 3% SF, then with this soggy weak lye, I have to add more lye?

I use KOH btw.
 
I weigh my KOH and NaOH when I get done weighing out what I want. Then I weigh it again before pouring any out the next time. If the weight is the same, then I know it did not absorb any moisture. If it does not weigh the same, then I know it has, and how much. I also put my bottle in a plastic bag while not in use to help it not absorb more moisture between uses.
 
The problem is...it's a bit hard to weigh properly in small batches. (beside my scale isn't that good too >_<)
And it is the lye in the container that I'm concern. Because I open the lye container a lot, I'm afraid that it is weaken (because of the moisture when I re-open many times).

But from your answer, what I can conclude is, it is indeed true that the lye can be weak because any contact with air moisture, isn't it?

This will be hard to calculate then (o.0)a
 
Your lye can indeed "weaken" when it absorbs moisture, even when the bottle is sitting closed. That is why I weigh my container after each use(I write down the amount on the bag I store it in.) Then weigh it again before use the next time.
 
Great idea Susie! How do you account for changes in the wt of your lye? If it weighs 10gms more today than it did the last time you used it, what do you do with your lye calc? Decrease the SF a bit? I'm curious as to how to make the adjustments.
 
I am allergic to math, so I tend to keep it simple. Once the weight difference reaches 20% of the total, I change the superfat by 1%. So my default superfat of 5% becomes 4%. Thus far it has worked for both NaOH and KOH. Although I have some clay cat litter(again, I lost mine in the move) and am about to try storing the bottles in there. Someone on here suggested that.
 
All excellent ideas, especially for those that live with constant high humidity. Luckily I live in a very arid climate but once monsoon season officially hits, that'll be a different story. Thanks Susie! :p
 
Those are great ideas. I recently had a failed batch due to old lye. I'm going to start weighing mine now so that doesn't again when I get the bottom of a container.
 
Masterbatching lye does not solve the problems of lye reacting with carbon dioxide in the air and absorbing water from the air. Masterbatching just makes it more convenient and quicker to use the lye, since you don't have to make up the solution from scratch every time.
 
I knew you all would have a discussion about this subject!

Hey all, we just moved into a home without air conditioning so I store my supplies in the cool basement with a dehumidifier running. It has been a wet and humid summer, my lye is forming large, hard clumps. I used them just the same, they dissolved and got very hot, just like normal. But, my soaps are tracing slower and my recent soap is very soft, day 2 and still really soft, too soft to push out of the PVC mold.

So, unless stored in dry conditions is it correct to assume the lye gets moist and reacts a little, loosing a little umph, making my soap over super fatted and soft? Could there be such a drastic difference??? This is the tail end of my last bulk buy, fresh stuff is in. I will use the fresh stuff for my next batch and see what happens.
 
I weigh my KOH and NaOH when I get done weighing out what I want. Then I weigh it again before pouring any out the next time. If the weight is the same, then I know it did not absorb any moisture. If it does not weigh the same, then I know it has, and how much. I also put my bottle in a plastic bag while not in use to help it not absorb more moisture between uses.

I would not have thought to do this. It's a good idea, because I have wondered the same thing about how would you know if your lye was absorbing moisture from the air.
 
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