# lye solution master batch?

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when you enter your recipe into the SoapmakingFreinds calculator (LOVE IT) you click "master batch" and the Water:Lye ratio at which you have made your master batch at the top. Then, in the lye section, you input the lye concentration you wish to use - say 33%.

NOTE - I make my master batch lye solution at a 50% concentration, or a 1:1 water:lye ratio - be sure to put in the ratio at which you made your master batch.

When it calculates your recipe - it will tell you how much additional liquid you need. See (poorly drawn ) circles below. I just threw in 100% olive oil at 500 grams oil weight for illustration. for this - the calcuator tells me to take 128...gms of my master batch, plus 64...gms of additional liquid - as I input a 33% concentration. Watch the numbers change as you change your concentration.

LOVE this calculator!

THank you ladies, I’m so excited and still so afraid. This journey is awesome and you ladies and gentlemen are the best! Thanks again

when you enter your recipe into the SoapmakingFreinds calculator (LOVE IT) you click "master batch" and the Water:Lye ratio at which you have made your master batch at the top. Then, in the lye section, you input the lye concentration you wish to use - say 33%.

NOTE - I make my master batch lye solution at a 50% concentration, or a 1:1 water:lye ratio - be sure to put in the ratio at which you made your master batch.

When it calculates your recipe - it will tell you how much additional liquid you need. See (poorly drawn ) circles below. I just threw in 100% olive oil at 500 grams oil weight for illustration. for this - the calcuator tells me to take 128...gms of my master batch, plus 64...gms of additional liquid - as I input a 33% concentration. Watch the numbers change as you change your concentration.

LOVE this calculator!

View attachment 36511

What would you consider a good beginning point for 50:50 solution. I was wondering if a gallon would be good?

I started with less than a gallon of distilled water cuz I only had one 1-gallon storage container at the time. I think I used about 2/3 to 3/4 of a gallon of water. What I did NOT do was confirm for my next batch how much concentrate it made - I can just tell you it fit into my 1-gallon container! If you make notes on yield for a 50% concentrate solution - or if someone else has - would be super to know!

I started with less than a gallon of distilled water cuz I only had one 1-gallon storage container at the time. I think I used about 2/3 to 3/4 of a gallon of water. What I did NOT do was confirm for my next batch how much concentrate it made - I can just tell you it fit into my 1-gallon container! If you make notes on yield for a 50% concentrate solution - or if someone else has - would be super to know!

The weight should be double what your water started out as, Clarice. But that doesn't really tell you the volume. So looking up DeeAnna's info on the subject, she says, "Lye solution can weigh up to 1 1/2 times more than the same volume of water" therefore you can use an algebraic equation (I'll leave that up to you) to determine how much volume you end up with. (How to determine weight by volume of a solution: https://sciencing.com/calculate-wv-weight-volume-5092442.html)

When I add 997 grams of NaOH to 998 grams of water, I get 1988 grams of solution after evaporation (from the heat produced and the resulting vapor rising into the air). I then add back in 6 grams of water to make sure the solution is 1994 grams total that I want. This is from my notes of when I first made Masterbatch lye. (It was the easiest one to find because it's the one I go back to when I want to refresh my memory of how I make it.) But I do not determine the volume because for me it doens't matter. I have more than enough empty lye containers to use and never need to fill more than 3 of said containers (Essential Depot lye NaOH containers are what I use.)

To determine how much solution will fit into your one-gallon container, you need to know the weight of your solution. I don't use a one-gallon container, so can't be much help on that score experientially, but here goes. 64 ounces = 1814 grams. The 50% lye solution can weigh up to 1.5 x 1814 grams, but you only want 1814 grams of solution since the volume of your container is limited to holding that amount.

I would say if you start out with 1360 grams of water and add 1360 grams of NaOH, the resulting solution it should fit into that one-gallon container. But you should double check the math to be sure before testing out my calculations. Also make sure the weigh the solution and add back in any water that evaporated off.

1 gallon of water weighs roughly 8 pounds and 1 gallon of 50% masterbatch solution weighs roughly 12 pounds. Divide the 12 pounds by 2 to get the weight of water and the weight of dry NaOH you need to fill the jug -- 6 pounds of each. I underfill my lye jug for safety -- it's much harder to pour without spilling from a jug that's brim full than it is to pour from a container that has a little room at the top.

I also want to caution folks that making a large jug of NaOH solution might be too much of a good thing. You don't want the container you pour from to be too heavy for safety and comfort.

One way around having to pour from a jug is to use a jug with a dispensing spigot. If you go that route, be absolutely certain the materials in the spigot are rated for use with concentrated NaOH. Most seals inside spigots you see in consumer products are not alkali resistant. If possible, I also recommend storing a jug with the spigot facing up so there's no liquid against the spigot in "storage mode." Set the spigot facing down only when you want to dispense.

I make only enough 50/50 solution that will get me through about 7 or 8 (1lb to 2.8lb) batches of soap, which for me calls for 2lbs 4 oz NaOH. The solution fits nicely in my detergent bottle w/pour spout, and is light enough for me to handle and pour without issue.

IrishLass

I am switching to the detergent pour spout - too many drips from my gallon vinegar bottle! and I like the idea of half way full - good safety tip!

Making a note for myself to come back to this thread. I am making 5 batches of soap on Saturday and master batching would save me a lot of time. I was seriously going to make up 5 batches of lye water but this sounds much easier. Irish Lass you are a gem!

Making a note for myself to come back to this thread. I am making 5 batches of soap on Saturday and master batching would save me a lot of time. I was seriously going to make up 5 batches of lye water but this sounds much easier. Irish Lass you are a gem!

Masterbatching is truly a game changer when you know you are going to be making a lot!

I used to take one afternoon to masterbatch before making soap. Get my big stainless steel pot out and masterbatch the oils, then masterbatch the lye. Then divide it out per batch. I used my leftover lard buckets to mix soap in, so I would just go ahead and weigh out the oils to have them ready to go and put the lid on. That way, on soaping day, just put the oils in the microwave, heat them up and stickblend the lye and additives in (I masterbatched my sugar, aloe juice, and EDTA also). Then color and pour. All done. 5-7 batches of soap done in the time it would take me to make one batch the long way.

No such thing as a stupid question!

I make a 50/50 masterbatch lye solution all the time, and it's actually very easy to figure out how much to add. This is how I proceed and the math equation that I use:

1) First, forget that you are using a 50/50 lye solution and just run your recipe through a lye calculator (like SoapCalc, etc..) as you would normally do, making sure to enter the superfat % that you would like to use and the lye concentration % that you normally like to soap at.

2) Once the calculator shows you the normal water amount and lye amount for your batch, utilise the following simple math equation to get the proper amount of 50/50 lye solution to pour out, and the extra water amount to pour out for your batch. FYI- this specific equation only works if you are using a 50/50 lye solution, but you can apply this same exact equation to whatever lye concentration you normally use for your batches, be it a 33% lye concentration or a 40% or a 34%- or whatever %. :

The equation:

Lye amount: Take your total lye amount that the lye calculator gave you and multiply it by 2 in order to get the amount of 50/50 lye solution to pour out.

Water amount: Take your total water amount that the lye calculator gave you and subtract from it the total lye amount that the lye calculator gave you to figure out how much extra water to add.

For example, say your recipe calls for 5 oz of lye and 12 oz of water. First, you would multiply 5 by 2 to get the amount of 50/50 lye solution to measure out, which comes to 10 oz, so pour out 10 oz. worth of the lye solution.

Then, to figure how much extra water to measure out for your batch, take the 12 oz that the calculator gave you and subtract from it the total lye amount the calculator gave you (which was 5): so.... 12 minus 5 equals 7, so you would measure out 7 oz of extra water for your batch.

HTH!
IrishLass
Hi there Irish Lass,

I'm new here and very much on a learning curve. In particular the 50/50 lye solution process, as it seems to make so much sense to me to do. I have a question on the steps to work out the recipe.

Say I use the example you gave using 5oz of lye and 12 oz of water.

I would need to measure out 10 oz of lye - but in order to get a 50/50 lye solution, would I need to use 10 oz of water to mix and dissolve the lye first?

I'm just trying to understand it. I'd like to make individual soaps so as to test different oil combinations.

Thank you .

It's as easy as mixing the lye and water as you would normally do, only you are mixing equal parts of lye and water together- a 50/50 solution. You can mix up as much as you have lye, water, space, and proper storage containers to store it in.

First, you want to make sure you have lye-compatable containers with tight-fitting lids to store the solution in once it's mixed and cooled. I use cleaned out All-brand detergent bottles made of HDPE #2 plastic, which is stamped on the the underside of the containers. HDPE #2 containers are great for the job, and if you can get one with a spill-proof spout like my All containers have- all the better.

Stay away from containers made of PETE #1 and PS #6. They are not lye-compatable. Glass is not recommended either because it will etch over time and the glass will break.

I mix my solution up along with some Tussa Silk fibers in a large Rubbermaid pitcher made of PP #5, cover, let it cool, and then pour it into my detergent bottles through a fine mesh stainless steel strainer. Then I cover tightly and store in an out-of-the-way place at room temp. until ready to soap.

I did an experiment over the spring/summer to see how long I could let some of my 50/50 lye solutiuon sit and have it still be good for soaping. So far, 5 months works great. I made the solution back in March and made 3 batches with it just last month (August). It's now cured and the soap came out as normal as if I had mixed my solution up yesterday.

IrishLass
Hi Irish Lass,

May I also ask at what temperature do you get your oils to be at before you mix in your pre-made lye solution?

Thank you.

Say I use the example you gave using 5oz of lye and 12 oz of water.

I would need to measure out 10 oz of lye - but in order to get a 50/50 lye solution, would I need to use 10 oz of water to mix and dissolve the lye first?

I'm just trying to understand it. I'd like to make individual soaps so as to test different oil combinations.
I'm not IrishLass but I do use masterbatched lye

The idea is you mix up a big batch of lye solution ahead of time that is enough for multiple soap batches, and then use what you need as you're soaping.You may want smaller batches, but when I make my 50/50 solution, I do 6lbs of lye and 6lbs of ice and have lye to last me a good many batches. Stored properly, I personally have used it up to 2 months later without issue (I ran out at that point, so it probably could have gone longer).

For the example of 5oz lye and 12oz water, I would then measure out 10oz of my lye solution so I have in my cup the equivalent of 5oz lye and 5oz water, and then add the additional 7oz water once that's been measured out. If you're going to be mixing lye for the specific batch of soap when you're making it, there's no real benefit to not just doing the whole 12oz of water and then the lye that I can think of.

I'm not IrishLass but I do use masterbatched lye

The idea is you mix up a big batch of lye solution ahead of time that is enough for multiple soap batches, and then use what you need as you're soaping.You may want smaller batches, but when I make my 50/50 solution, I do 6lbs of lye and 6lbs of ice and have lye to last me a good many batches. Stored properly, I personally have used it up to 2 months later without issue (I ran out at that point, so it probably could have gone longer).

For the example of 5oz lye and 12oz water, I would then measure out 10oz of my lye solution so I have in my cup the equivalent of 5oz lye and 5oz water, and then add the additional 7oz water once that's been measured out. If you're going to be mixing lye for the specific batch of soap when you're making it, there's no real benefit to not just doing the whole 12oz of water and then the lye that I can think of.
Thank you for this Katili. I do appreciate your reply. If I did decide to use the lye solution, assuming I use the lye at room temperature, at what temperature should I get my oils at? Thank you

Hi, not @IrishLass or @katili but here’s what I do. I make MB lye at 50/50, and only do either 1 or 2 lbs of lye at a time. When I add my extra liquid to my MB lye, it does heat back up a bit so I let it cool to somewhere around 80-90f. My oils are usually around 90f.

Yep, my lye solution heats back up to about 120 when I add the extra water to it, so I usually do that first and then by the time I'm done getting everything else ready, it's back in the 80-ish degree range, which is about where my oils end up as well.

Hi, not @IrishLass or @katili but here’s what I do. I make MB lye at 50/50, and only do either 1 or 2 lbs of lye at a time. When I add my extra liquid to my MB lye, it does heat back up a bit so I let it cool to somewhere around 80-90f. My oils are usually around 90f.
Thank you for explaining the solution heats back up, now that makes total sense.

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