Trying to understood Lye water master batching

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I masterbatch my KOH/NaOH blend at the same time. Why not? You know how much you need per batch.

Susie, how you do that please?

No, madison was correct. My math was off, either because I was too tired to check my own work, or just too tired. Anyway, I have corrected my original post to reflect the proper math. And the double checking method I normally use to check my math. So I hope you haven't yet made any soap with the wrong calculations!

I am now confused, which one is the right one?
 
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Equal amount of lye and water = 62.4 lye + 62.4 water.
According to Earlene's example recipe, you need 137.1 g water total. So with your "equal amount of lye and water" (from the masterbatch) you have taken care of 62.4 g water out of this 137.1 g. Which means you still have to add 74.7 g.
At least this is how I would calculate it.
atiz, you were right, I was mistaken, I just got it, sorry about that.
Thank you for being around.

Sorry, I meant atiz was correct. SORRY again. I did not mean to confuse you!
No worries earlene. thank you. You explained the idea in general, I got it but didn't follow the exact math, I was very exhausted today. Thanks to atiz for chiming in.
 
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No worries earlene. thank you. You explained the idea in general, I got it but didn't follow the exact math, I was very exhausted today. Thanks to atiz for chiming in.

Well, the cool thing is that if you use the Soapmaking Friend calculator here at SMF (still under development, but working pretty well, it seems), you can plug the masterbatch lye into it and come up with the correct numbers without having to do all the calculations yourself.

I tried it out a bit ago with the masterbatch function and it does work. I had some trouble figuring out how to enter the MB lye as there are no instructions attached (that I could find), but by choosing 1:1 as the water to lye ration (actually that should have been pretty easy to figure out, but for some reason I thought I would need to put in 50%, but that wasn't an option) it works out perfectly.

Even so, learning the math first is really a good thing to know how to do. Then having something like all these great folks here at SMF to help double check our process (math included) is really helpful. The day may come when a lye calculator isn't available and we want to make soap.
 
OK, I am not the maths wiz at all. Y'all's calculations above made my head hurt.

Having said that, I know that I can get about 6 batches of soap from 32 oz NaOH, so I take the amount of NaOH I use per batch, 5.27 oz x 6 = 31.62 oz
I just repeat that simple equation for the KOH- 0.43 oz x 6 = 2.58 oz.
Add those together for the amount of water to add 31.62 + 2.58 = 34.2 oz water.
Add both alkali together, add slowly to water. Allow to cool. Pour into bottles. Label appropriately. Easy Peasy.
 
So, now that I'm convinced that I *can* masterbatch - what can I store it in? I bought a 1 gallon pitcher yesterday, made of PP #5. Will that be okay? The DH is worried that it's not HDPE...
 
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Why is it important to have a tight fitting lid on the storage container? Is it to prevent evaporation? If there is evaporation, do you just weigh and then add the water that's lost?
 
No -- masterbatched NaOH won't evaporate; it will absorb water and you don't want that. Also exposure to air will reduce the purity of the NaOH because it reacts with carbon dioxide in the air.

In addition, you want to be safe and minimize the chance for spills or leaks. A screw-on lid is safest -- a snap on lid is not as good.

edit: Never fasten a lid on tight while the lye solution is still hot. You don't want pressure to build up in the container. Just put the lid or cap on the container but leave it loose until the solution cools. Then cap the container tightly.
 
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Even though I don't have children in my home, I prefer to use a bottle with a child-safe lid. With the bottles I use, I know that if I knock over my bottle of lye it will not leak. I know this to be the case because #1, I have tested it, and #2, I have actually knocked a bottle over once or twice. Once, just a couple of days ago, in fact. (safely in my sink, but still it did not leak)

You also need to label it as lye and poisonous.

What I use for storage of my master batch lye is the bottles that Essential Depot's lye comes in because:
1. they are made of HDPE plastic,
2. they have child proof caps,
3. they are already labeled appropriately for the contents*, and
4. they are the perfect size for my hands and not too heavy for me to lift and pour when full.

* But I still add additional labeling information to include the following:
Masterbatch 50% Lye Concentration
date made
amount in solution (which I change as I use it) - because I like to keep tract of how much I have left
On the bottom of the container I have the weight of the container, so I can deduct that from the weight of the bottle as I do my calculations.
I use masking tape and a Permanent Marker to add the additional labeling information on the bottles and when I make new batches, remove the old tape, wash out the bottle with plain water and allow to dry before re-filling with new lye solution.

For safety I still keep my masterbatch lye bottles inside another lye-safe plastic bucket just in case something unforeseen happens and to ensure that I have a doubly safe method of transporting it from my storage area to my soaping area. Granted, for me that is only about a 6 meters away from my kitchen sink, but it makes me feel that I am being as safe as possible.
 
"...For safety I still keep my masterbatch lye bottles inside another lye-safe plastic bucket..."

Good point, @earlene. I do this for my dry NaOH and KOH as well as lye solution. I have personal experience with a leaky NaOH container to know this "belt and suspenders" method is a wise idea.
 
So, now that I'm convinced that I *can* masterbatch - what can I store it in? I bought a 1 gallon pitcher yesterday, made of PP #5. Will that be okay? The DH is worried that it's not HDPE...
I use old liquid laundry detergent bottles with a 5 on the bottom. I soak the labels off and make my own labels so no one gets confused. I store them in a cupboard which is easily childproofed should l ever be in the lucky position of needing that facility.
 
No -- masterbatched NaOH won't evaporate; it will absorb water and you don't want that. Also exposure to air will reduce the purity of the NaOH because it reacts with carbon dioxide in the air.

In addition, you want to be safe and minimize the chance for spills or leaks. A screw-on lid is safest -- a snap on lid is not as good.

edit: Never fasten a lid on tight while the lye solution is still hot. You don't want pressure to build up in the container. Just put the lid or cap on the container but leave it loose until the solution cools. Then cap the container tightly.
If it absorbs water, I assume that changes the lye ratio thereby increasing the amount of water in the batch. Other than that, are there any ill effects? I've not noticed any.
 
If it absorbs water, I assume that changes the lye ratio thereby increasing the amount of water in the batch. Other than that, are there any ill effects? I've not noticed any.
It would increase the amount of water, also in the masterbatch --- so unless you measure every time how much the total water increased, you won't know exactly how much solution you need to have a given amount of lye. That seems a bit inconvenient when it comes to masterbatching. (It basically results in a variable % of masterbatch solution, a % you might not even know.) I wasn't even aware of the CO2 reaction but that just seems to make the situation worse; at the end of the day you'll have a considerably weaker mb than you think you have, which will result in some extra superfat in your soap.
 
If it absorbs water, I assume that changes the lye ratio thereby increasing the amount of water in the batch. Other than that, are there any ill effects? I've not noticed any.

What I said already -- "...Also exposure to air will reduce the purity of the NaOH because it reacts with carbon dioxide in the air..." and "...you want to be safe and minimize the chance for spills or leaks..."
 
ok here I go...

50/50 measured and mixed

*An example of how to add extra water for recipe
Now my recipe at 33% of water as the percentage

Water weight is : 10.56oz
Lye 4.41 oz

Multiply lye by 2/ 4.41x 2=8.82 oz

Now I pour out 8.82 oz of 50/50 water solution

*Next calculate extra water needed:

Recipe water amount is 10.56 oz
Subtract lye amount from water amount on recipe / 10.56 oz- 4.41 oz = 6.15 oz

6.15 oz = the extra amount of water needed

So... 50/50 lye water solution that was poured out was 8.82 oz+ 6.15 oz extra weather for particular recipe.

Tell me, is this correct??!! You have the math correct. I master batch into gallon jugs, four at a time. You can add the additional liquid innany form you want...milk, beer, purée, etc.
 
What I said already -- "...Also exposure to air will reduce the purity of the NaOH because it reacts with carbon dioxide in the air..." and "...you want to be safe and minimize the chance for spills or leaks..."
I get the safety issue; I just didn't mention it. I wanted to understand the effect of a reduction in purity on the final soap. Sometimes I make up my lye solution but then something happens and I have a delay of several days, or even weeks, before I actually use it. (It sits covered at the back of my counter out of the way). I wondered what impact the reduction in purity might have on the finished soap. I understand the possible increase in the superfat.
 
I get the safety issue; I just didn't mention it. I wanted to understand the effect of a reduction in purity on the final soap. Sometimes I make up my lye solution but then something happens and I have a delay of several days, or even weeks, before I actually use it. (It sits covered at the back of my counter out of the way). I wondered what impact the reduction in purity might have on the finished soap. I understand the possible increase in the superfat.
decrease in purity would also result in a very soft, unsaponified soap. Yes, increase the superfat, but also not completely saponify the oils in an effecient way.
 
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