Adding to Master-batch Lye

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I tried to add to my fully-reacted, room-temp master batch lye by pouring in equal parts of new/additional lye and water. Everything seemed fine, as it cleared up over a day or so. But, I used it today, and when I added the extra water it heated up a lot! Sort of defeats the purpose of master batching. I guess the lesson learned is to use up your master batch before making more. It’s not like a sour dough that you can feed. Have y’all found this to be true?
 
Was it more than with the normal masterbatch?
Well, there is no “normal” because that was my first-ever batch that I tried to add to. By volume, why Imadded was about 1/4 existing batch. My GUESS is that the added volume wasn’t enough fully react inside the already 50/50 solution. It doesn’t seem to have impacted the saponification process (although I have cut the loaf yet. My question is for you master-butchers, how do you replenish you 50/50 solution? Do you use it all up before making more?
 
Well, there is no “normal” because that was my first-ever batch that I tried to add to. By volume, why Imadded was about 1/4 existing batch. My GUESS is that the added volume wasn’t enough fully react inside the already 50/50 solution. It doesn’t seem to have impacted the saponification process (although I have cut the loaf yet. My question is for you master-butchers, how do you replenish you 50/50 solution? Do you use it all up before making more?
I make a new batch in a different jug, wait for it to cool and add it to the masterbatch bottle.

Your masterbatch lye will heat up when you add it to your oils as it goes through saponification.

The purpose of masterbatch it is to make it easy to make soap not necessarily to soap cool.
 
I make a new batch in a different jug, wait for it to cool and add it to the masterbatch bottle.

Your masterbatch lye will heat up when you add it to your oils as it goes through saponification.

The purpose of masterbatch it is to make it easy to make soap not necessarily to soap cool.

I can see that mixing separately is probably best practice. The first time I added the original master lye to the additional water, I didn’t get any re-heating, so I was surprised yesterday when it heated up almost as hot as an original water/lye reaction. The benefit, to me, of a master batch is to eliminate the +/- 30 minutes of waiting for the lye/water to cool down while keeping the oils at a soaping temp.
 
I have yet to have my MB lye heat up significantly - even when I added sugar to it (who knows, maybe sugar never heats up lye, but I thought it would!)

As the additional liquid needed to bring my 50% concentration MB lye solution to the correct concentration for various recipes, I have used distilled water, aloe juice and water into which I had added sugar. I have never had significant heating. I too make new MB in a new jug.

Good luck!
 
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When I add water to 50% masterbatch NaOH solution, the mixture doesn't heat up as much as when I make the original lye solution. The chart I have on diluting room temperature 50% NaOH to about 30% NaOH shows the final temperature of the end mixture will be about 135 F. That's warm, but it's not nearly as hot as when solid NaOH is dissolved to make the 50% masterbatch.

If I start with fats at 90-100 F, adding the masterbatched lye and the extra water will only raise the overall batter temp by a few degrees in my experience. That's the key thing to consider.
 
Okay, I think I may be ready to try masterbatching, so I'm reaching out to the all knowing ones on the forum! When I masterbatch, so I just add enough of my lye water (I'm thinking of just doing it at my regular 2:1 mixture to store) as the amount of water in the recipe, correct? Sorry I'm so stupid at math! Thanks in advance...
 
Okay, I think I may be ready to try masterbatching, so I'm reaching out to the all knowing ones on the forum! When I masterbatch, so I just add enough of my lye water (I'm thinking of just doing it at my regular 2:1 mixture to store) as the amount of water in the recipe, correct? Sorry I'm so stupid at math! Thanks in advance...
Whatever concentration of masterbatch you use (I think most people have 50% instead of your 33%), you must make sure you use enough to get the correct lye amount that your recipe requires. So first you focus on the amount of lye, not the amount of water.

If your recipe requires 5.3g lye, then you add as much lye solution as you need to take care of that 5.3 g lye. If your masterbatch is 50%, then you will have 5.3 g lye + 5.3 g water in it (so 10.6 g masterbatch total).
Next, you have to make sure that your water/liquid amount is good. So, if you need, e.g., 12 g water in your recipe, then --- since you have already added 5.3 g with your masterbatch lye solution --- you will need to add 6.7 g extra.
If your masterbatch solution is 33%, the numbers will be different; but you still need 5.3 g lye in your recipe, and that's what you have to focus on. You have to add 5.3 g lye, so your masterbatch in your case will contain 10.6 g water (since it is 1:2 ratio). Again, if your recipe needs 12g water total, you'll need to add 1.4g water extra.

I think the easiest way to think about this is as if the lye and water were just sitting next to each other in your masterbatch. (Which is not the case since it is a solution, but for math purposes it is easier.) You treat the lye part as lye, and treat the water part as water. You just have to make sure you know how much lye and how much water "is sitting" next to each other in your masterbatch. If your solution is 50%, then they are matched up -- equal lye, equal water. So whatever masterbatch amount you have, half of it is lye, half of it is water, and you want to count them as such in your recipe. If your solution is 33%, then you get twice as much water as lye. So whatever masterbatch amount you have, 1 third of it is lye, 2 thirds of it is water. You still count the lye as lye, the water as water.

Okay I think I tend to overexplain everything.... sorry.
 

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