# 50/50 lye solution question

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#### MommaSoaper

##### Well-Known Member
Hi all,

If my recipe calls for 138.35oz of lye, then when using a 50/50 lye solution, I’d measure out 276.70oz. of the solution correct?

If the recipe calls for 280.89oz of water, then how much remaining water would be needed after the solutions been added? 4.19oz? Or would it be an additional 140.45oz of water?

Thank you for clarifying this!

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If my recipe calls for 138.35oz of lye, then when using a 50/50 lye solution, I’d measure out 276.70oz. of the solution correct?
Correct.

If the recipe calls for 280.89oz of water, then how much remaining water would be needed after the solutions been added? 4.19oz? Or would it be an additional 140.45oz of water?
It depends on what lye concentration you want to use. If you use the typical 33% lye concentration (aka 2:1 water:lye ratio), then remember that half of your MB lye solution weight is NaOH, and half is water.

So in your example, you have already added 138.35 oz of water when you measured out your MB lye solution. You will add another 138.35 oz of water to reach a 33% lye concentration.

BTW, if you use SoapmakingFriend, simply click the MB lye solution button, and put in your MB lye solution concentration. Then select your desired final lye concentration down the screen a bit further. The calculator will then tell you how much additional liquid is required with no math calcs needed on your part.

Correct.

It depends on what lye concentration you want to use. If you use the typical 33% lye concentration (aka 2:1 water:lye ratio), then remember that half of your MB lye solution weight is NaOH, and half is water.

So in your example, you have already added 138.35 oz of water when you measured out your MB lye solution. You will add another 138.35 oz of water to reach a 33% lye concentration.

BTW, if you use SoapmakingFriend, simply click the MB lye solution button, and put in your MB lye solution concentration. Then select your desired final lye concentration down the screen a bit further. The calculator will then tell you how much additional liquid is required with no math calcs needed on your part.
Thank you so much!

And this is why I Master Batch my Lye Solution as 'ready-to-use'. LOL

And this is why I Master Batch my Lye Solution as 'ready-to-use'. LOL
And this is why I Master Batch my Lye Solution as 'ready-to-us
And this is why I Master Batch my Lye Solution as 'ready-to-use'. LOL
Can you explain the benefit of MBing at 50% vs 33
And this is why I Master Batch my Lye Solution as 'ready-to-use'. LOL
Curious, for large batches, let’s say 50 pounds plus- is a 40% lye concentration recommended? I understand that it varies on complexity of aesthetics but is there any common or general ground on this thought?

Much appreciated all!

I used to MB lye at 1:1, but because my soaping studio is cool I had problems with lye crystallizing out of solution, so now I do like @TheGecko and MB the concentration I soap with. I also add sodium gluconate, sorbitol, and sodium lactate when I make my MB. Some people who want to add other liquids make their lye MB at 1:1 and then add coconut milk, goat milk, what have you, at soaping time to make the concentration they want to soap with. They might stick blend the liquid into the oils, or add it as a frozen solution, to keep from scorching it.

@Vicki C I sooooo want to try this, but I’m stuck on the math (of course).

Normally I weigh my additives (sorbitol and sodium citrate) by percentage of oils, and dissolve that in my additional water.

Would you be so kind to share how you determine the percentage of additives in your MB lye solution in such a way that it works out to be the percentage you want in any given batch of soap? Thank you!!

Can you explain the benefit of MBing at 50% vs 33

Curious, for large batches, let’s say 50 pounds plus- is a 40% lye concentration recommended? I understand that it varies on complexity of aesthetics but is there any common or general ground on this thought?

Much appreciated all!
I personally don't think that there is an 'benefit' of Master Batching a 50/50 solution. I considered it, but then I would still have to do the match and I'm not saving on storage space since I would still need extra water to make up for my whatever Lye Concentration.

Lye Concentration is a personal choice and is dependent on a number of factors...like your recipe and your environment. Most of the time I use a 33% Lye Concentration, but I live in the Pacific Northwest of the US and we get a lot of rain during the Winter and my garage is not insulated so I go with a 35% Lye Concentration...elsewise it will take all winter for my soap to cure.

I have a lye tank and just mixed up a 50/50 solution with ice two days ago. The tank is not heated but I’m out west so it isn’t cold here yet. I keep the studio above 70. Just turned the heat up since I read that the room should be at 77. I’m reading a lot of conflicting information on precipitation and temperatures…. Thoughts?

@Vicki C I sooooo want to try this, but I’m stuck on the math (of course).

Normally I weigh my additives (sorbitol and sodium citrate) by percentage of oils, and dissolve that in my additional water.

Would you be so kind to share how you determine the percentage of additives in your MB lye solution in such a way that it works out to be the percentage you want in any given batch of soap? Thank you!!
Not @Vicki C, but it is fairly simple if you are using PPO for your additive.

I MB my Lye Solution when I MB my Oils/Butters and I do it in batches based on 160 oz Oil Weight (10 pounds). So I would need to add 10 teaspoons (or 3 tablespoons and 1 teaspoon) of Sodium Lactate per batch of Lye Solution.

And I wish I could say that I planned it that way, but it had to do with how much my pot holds and what I can safely move from stove to bucket.

I have a lye tank and just mixed up a 50/50 solution with ice two days ago. The tank is not heated but I’m out west so it isn’t cold here yet. I keep the studio above 70. Just turned the heat up since I read that the room should be at 77. I’m reading a lot of conflicting information on precipitation and temperatures…. Thoughts?
As noted by @DeeAnna you want to keep your Lye Solution at least 65F/18C as "the sodium hydroxide will precipitate out (become solid) when the mixture gets too cold". Lye Solution and/or Sodium Hydroxide that is exposed to the air "will absorb water from the air and react with carbon dioxide gas in the air. Both of these things will reduce the concentration of NaOH, which is not good."

With the above said (I wrote it two years ago) I can attest go going below 65F without issue. Not by choice, my husband absolutely refuses to leave the heat running after we go to bed, the house has gotten cooler than 65F during the winter. Fortunately we live in the Mid-Willamette Valley in Oregon so it rarely gets below 40F outside and the house is fairly well insulated; I also store the jugs inside my soap cart during the winter which keeps them a little bit warmer

I have a lye tank and just mixed up a 50/50 solution with ice two days ago. The tank is not heated but I’m out west so it isn’t cold here yet. I keep the studio above 70. Just turned the heat up since I read that the room should be at 77. I’m reading a lot of conflicting information on precipitation and temperatures…. Thoughts?
@TheGecko gave a good response above. If your solution is staying at 70F, you should be fine.

I will add my experience, which is that when our house has gone below 65F (during winter, either from turning down the heat at night, or leaving on vacation for a week), I have gotten chunks of "lye ice" from precipitation. I do live in a colder climate than Gecko, and my solution is stored in a cabinet near an outside wall, which most certainly didn't help.

Not @Vicki C, but it is fairly simple if you are using PPO for your additive.

I MB my Lye Solution when I MB my Oils/Butters and I do it in batches based on 160 oz Oil Weight (10 pounds). So I would need to add 10 teaspoons (or 3 tablespoons and 1 teaspoon) of Sodium Lactate per batch of Lye Solution.

And I wish I could say that I planned it that way, but it had to do with how much my pot holds and what I can safely move from stove to bucket.
Unfortunately, I use % of oil weight for my additives, and I make my MB lye solution using 4lb of NaOH at one time. That allows me to completely use up two, 2-lb bottles of NaOH. That way, all the NaOH in those two bottles is mixed at the time the bottle is opened, so less exposure to air, etc.

Fortunately, I do tend to use the same recipe most of the time, so the ratio of MB lye to oils is going to remain consistent from batch to batch. Maybe I just need to do the calcs for a 1000g batch of my usual recipe. Then I can determine how my usual %-of-oil-weight additives translates into %-of-MB-solution-weight.

Any thoughts from the mathematically-inclined folks whether that idea is correct?

@Vicki C I sooooo want to try this, but I’m stuck on the math (of course).

Normally I weigh my additives (sorbitol and sodium citrate) by percentage of oils, and dissolve that in my additional water.

Would you be so kind to share how you determine the percentage of additives in your MB lye solution in such a way that it works out to be the percentage you want in any given batch of soap? Thank you!!
Oh, sure! I do everything by weight rather than teaspoons ppo. It’s so long since I set up my spreadsheet, but it was based on .5% sorbitol ppo and .5% sodium gluconate per total batch weight. My oils are masterbatched so I know what the lye should be depending on the weight of the oils. And sodium lactate at 1 t ppo but at some point I lowered that - I measured how much a teaspoon weighed, I think it was 6 grams. In any case I start with a container of NaOH, weigh that and then base my measurements for water and additives off of that. I used to weigh exactly 924 g of lye which was what I needed for 6600 g of oil (six or four loaves depending on how I pour and cut) and then I realized I could just adjust the amounts based on the amount of lye - I have an empty container and just tare that off. Here is a snippet of my calculation spreadsheet - it goes up to 1200 g NaOH because now I buy big buckets of lye and fill old 2 pound lye containers, but I don’t measure while I fill.
The first line is my old measurement method.
Oh the “sum” is what it should add up to - usual total is what I typically get. I don’t know why, I guess evaporation when everything is hot. I double check the weight at the end to make sure it’s within a few grams of my “usual total”.
I hope this makes sense!
Lastly I have a chart pinned up in front of my work table that tells me lye per gram oil, (1-9, 10-100 by tens, 100-900 by hundreds, etc.) so I don’t have to get out my phone to do the calculations all the time.

 NaOH Water SG Sorbitol SL Sum Usual total 924 1650 47 33 60 2714 2700 880 1571 45 31 57 2585 2571 881 1573 45 31 57 2588 2574 882 1575 45 32 57 2591 2577

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Maybe I just need to do the calcs for a 1000g batch of my usual recipe. Then I can determine how my usual %-of-oil-weight additives translates into %-of-MB-solution-weight.
Yes! This is what I do, I don’t know if I explained it clearly.

I used to MB lye at 1:1, but because my soaping studio is cool I had problems with lye crystallizing out of solution, so now I do like @TheGecko and MB the concentration I soap with.
@Vicki C, I am starting to see lye chrystallize around the top of my MB jar, it kind of flakes off when I open it. Why is that the crystallization would not be a problem if you MB at your "regular" concentration, is it just that it is less concentrated and as a result you have less flaking? It a little worrisome, and I'm having some differences with trace, so I was actually thinking of either lowering my superfat percentages or just going back to mixing lye water for each batch instead of MB'ing.

And this is why I Master Batch my Lye Solution as 'ready-to-use'. LOL

@Vicki C, I am starting to see lye chrystallize around the top of my MB jar, it kind of flakes off when I open it. Why is that the crystallization would not be a problem if you MB at your "regular" concentration, is it just that it is less concentrated and as a result you have less flaking? It a little worrisome, and I'm having some differences with trace, so I was actually thinking of either lowering my superfat percentages or just going back to mixing lye water for each batch instead of MB'ing.
You are talking about dried-up lye solution on the rim; that is a different issue than precipitation, and it doesn't affect the strength of the remaining solution. To prevent the buildup, wipe the pouring edge completely dry after each pour, and before you reattach the lid.

Precipitation happens when the NaOH "un-dissolves" from the water and falls to the bottom of the container, usually due to a temperature drop to 65F or below. The undissolved or precipitated NaOH often solidifies into ice-like chunks or crystals at the bottom. That IS a problem and DOES affect the concentration of the remaining liquid.

That's exactly my problem, the stuff on the rim. Sometimes it seems like there's quite a bit of it. I wipe it (the dried up stuff) off each time before I pour the MB, and it has reformed by next time I use it. I don't make huge amounts of MB, maybe about 2kgs at a time, but I thought that maybe over time I was losing enough lye to make a difference. Thanks for the tip about wiping the pouring edge dry, hopefully that's it!

@Vicki C, I am starting to see lye chrystallize around the top of my MB jar, it kind of flakes off when I open it. Why is that the crystallization would not be a problem if you MB at your "regular" concentration, is it just that it is less concentrated and as a result you have less flaking? It a little worrisome, and I'm having some differences with trace, so I was actually thinking of either lowering my superfat percentages or just going back to mixing lye water for each batch instead of MB'ing.
Mine does that too and I don’t worry about it. The problem I was having when I masterbatched at 1:1 was it was crystallizing out at the bottom of the containers and creating a hard clump. I’m not sure, but I think that it is more of a problem when the solution is saturated - when there is as much NaOH as the water can hold, if it gets cold, it starts to crystallize and then just snowballs, or lyeballs, as it were.
You are talking about dried-up lye solution on the rim; that is a different issue than precipitation, and it doesn't affect the strength of the remaining solution. To prevent the buildup, wipe the pouring edge completely dry after each pour, and before you reattach the lid.

Precipitation happens when the NaOH "un-dissolves" from the water and falls to the bottom of the container, usually due to a temperature drop to 65F or below. The undissolved or precipitated NaOH often solidifies into ice-like chunks or crystals at the bottom. That IS a problem and DOES affect the concentration of the remaining liquid.
Everything @AliOop said.

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