# Trying to understood Lye water master batching

### Help Support SoapMakingForum:

#### Cal43

Supporting Member
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??!!

#### Clarice

##### We are one...
Supporting Member
I master batch at a 1:1 water:lye ratio and then use the SoapMakingFriend calculator to tell me the additional liquid needed.

https://www.soapmakingfriend.com/soap-making-recipe-builder-lye-calculator/

also great discussion in a recent thread that will tell you a lot you need to know.

really good information

I understand the principles behind the math - but have not done it given the fabulous recipe builder!

#### The Efficacious Gentleman

But yes, you are correct.

Required lye X 2 is the amount of 50/50 you use.

Required water - half of the 50/50 amount (or the required lye amount, they're the same number and it saves a maths step) is the amount of extra water to put in.

Heads up in case you haven't heard about it ... The master batched mixture will warm up when you add water in to it.

#### SoaperForLife

Supporting Member
At the risk of sounding like an idiot, why do people master batch lye?

#### The Efficacious Gentleman

If you like to soap at room temperature, it means that you don't have to wait as long for the lye water to cool.

It can also generally save time if you make lye once for a few batches l, you just have to melt the oils and you're pretty much good to go

#### Cal43

Supporting Member
But yes, you are correct.

Required lye X 2 is the amount of 50/50 you use.

Required water - half of the 50/50 amount (or the required lye amount, they're the same number and it saves a maths step) is the amount of extra water to put in.

Heads up in case you haven't heard about it ... The master batched mixture will warm up when you add water in to it.
Oh good to know. Around what temperature does it usually go to?

#### The Efficacious Gentleman

Not as hot as when you first make it, but still quite warm. I would use the same quality container that I would use if I were making fresh lye solutions

#### shunt2011

Staff member
At the risk of sounding like an idiot, why do people master batch lye?
It allows me to have a batch of lye ready to go. It's mixed and cooled. I generally mix 4 lbs lye and 4 lbs water add my silk and let it cool. I don't have to wait for my lye to cool down.

I add my extra needed liquid (milks/beer etc) to my oils not to my lye mixture.

#### Clarice

##### We are one...
Supporting Member
Maybe because I make small batches (still trying to find my perfect recipe) i do not find much heating up with my master batch when i add water.

Yesterday I mixed full cream with my master batch (again, small batch - 8 oz) and the temp barely bumped. Cream was cold. I did, however, make the mistake of letting it sit for a bit, and I had sort of lye-glue. I rescued with a stir - but it was still thicker than I would like. lesson learned - stir cream in gently and use immediately!

This may be very different for larger batches - I only needed something along the lines of 1.6oz additional liquid and 2.4 oz master batch

#### DeeAnna

##### Well-Known Member
Why do I masterbatch? Cuz in the long run, the masterbatch makes my soaping easier and safer and more pleasant.

I don't have to deal with dry NaOH nearly as often with all the safety issues of dealing with the fumes and triple checking that all the NaOH is dissolved and all that hassle. I mean ... whether you make lye solution for 1 batch or for 10, the hazards are exactly the same, so why do I want to do this 10 times rather than just one?

In addition I don't have to wait for hot lye to cool to a reasonable temp for CP soap. Even if the recipe uses extra water-based liquid, adding that to the soap batter doesn't heat the batter enough to be a concern.

#### Cal43

Supporting Member
I master batch at a 1:1 water:lye ratio and then use the SoapMakingFriend calculator to tell me the additional liquid needed.

https://www.soapmakingfriend.com/soap-making-recipe-builder-lye-calculator/

also great discussion in a recent thread that will tell you a lot you need to know.

really good information

I understand the principles behind the math - but have not done it given the fabulous recipe builder!
Yes I printed some of the information from that thread. I was just checking to see I I got before going forward. I going to check it out in there calculator also.

#### cmzaha

Supporting Member
Same as everyone else, I have no patience to wait for lye to cool so I master batch 50/50 which is easier math for me.

#### Clarice

##### We are one...
Supporting Member
And Carolyn I think you made point about decanting master batch into smaller containers for easy pours? Super idea. I went to store and got \$1.49 3/4 gallon soap with nice pour spout and I use that for working and keep bigger bottles for refilling the little one. Easier on my hands

#### jcandleattic

##### Well-Known Member
At the risk of sounding like an idiot, why do people master batch lye?
It is a HUGE time saver and there is no waiting around for your solution to cool down to soap.

I also masterbatch my main 3 recipes, so from time I start soaping to putting the soap in the corner to do it's thing, a batch for me can take as little as 6 minutes per or to up to 10-12 minutes depending on the intricacy.

In one day if I am super ambitious, and have everything organized, I can make up to 7 batches of soap in less than 2 hours. That frees up pretty much the rest of my weekend for me. (I only soap on weekends as I have a ft job outside the home)

Supporting Member
At the risk of sounding like an idiot, why do people master batch lye?
I just started master batching both lye and oils. It makes the process go so much smoother and gets you to the fun part faster. I'm not constantly waiting on my lye to cool and trying to make sure the lye water and oil are at similar temps before combining. It also helps with clean-up. I can't believe I waited so long to try it.

On master-batching lye.... I'm thinking it's like a sourdough starter. So long as I add equal amounts (by weight, of course) of new lye and water to my existing master batch and give it time to react, I'm still good to go, right?

And Carolyn I think you made point about decanting master batch into smaller containers for easy pours? Super idea. I went to store and got \$1.49 3/4 gallon soap with nice pour spout and I use that for working and keep bigger bottles for refilling the little one. Easier on my hands
I though about parsing out my lye like a did my oils, but I got nervous having a bunch of little lethal jars floating around. I like keeping it in one container labeled as Lye/Danger!/Poison!/Don't Touch!! until needed then pour out just what I need. Just my 2 cents.

Last edited by a moderator:

#### jcandleattic

##### Well-Known Member
I though about parsing out my lye like a did my oils, but I got nervous having a bunch of little lethal jars floating around. I like keeping it in one container labeled as Lye/Danger!/Poison!/Don't Touch!! until needed then pour out just what I need. Just my 2 cents.
I make 24 lb master batch lye solution (12lbs lye/12lbs water) and that sucker is heavy to lift for my old shoulders.

I keep the master masterbatched lye in a large liquid detergent bottle and then I have 3 smaller of the same type of bottle I use to fill from my master masterbached lye. Much easier to manage for me. I fill the 3 at the same time I make the master batch then the big bottle isn't as heavy to lift to refill the others.

I hope that makes sense.

Last edited:

Supporting Member
I make 24 lb master batch lye solution (12lbs lye/12lbs water) and that sucker is heavy to lift for my old shoulders.

I keep the master masterbatched lye in a large liquid detergent bottle and then I have 3 smaller of the same type of bottle I use to fill from my master masterbached lye. Much easier to manage for me. I fill the 3 at the same time I make the master batch than the big bottle isn't as heavy to lift to refill the others.

I hope that makes sense.
Total sense. I was just scared to do it because I'm basically a control freak. I don't even like keeping a full single large container around. See my comment below that one. Thinking my best solution may be to just add equal measures of water and lye to replenish my master batch as it is used down...still keeping it all in a single container. Unless somebody tells me that "feeding" a master batch is a bad idea.

#### IrishLass

Staff member
At the risk of sounding like an idiot, why do people master batch lye?
LOL- no worries- I used to wonder the same thing. I kept seeing the term bandied about back in the day, but never really looked into it until the day my eye caught a little snippet of info about how with masterbatching, one did not have to make fresh lye solution for every single batch.......and that with 50/50 master-batching the math was super easy to do in order to adjust it to any batch no matter what my lye concentration. Being that making lye solution is my least favorite thing to do with soapmaking, and knowing that the math to adjust for different lye concentrations would be easy, I jumped right on that bandwagon faster than you can say boo! It's so nice to be able to make several batches without having to don my extra super safety lye mixing gear every single doggone time I wanted to make a batch of soap. It's also nice that the lye solution stays good for a very loooooong time....years (if stored properly).

Total sense. I was just scared to do it because I'm basically a control freak. I don't even like keeping a full single large container around. See my comment below that one. Thinking my best solution may be to just add equal measures of water and lye to replenish my master batch as it is used down...still keeping it all in a single container. Unless somebody tells me that "feeding" a master batch is a bad idea.

I've never fed a lye master-batch (I normally have 2 containers going), but as long as you keep track of its weight before and after each time you use it, and the weight matches up with what it weighed after the last time you used it, I personally don't see there being a problem with feeding it.

IrishLass

#### penelopejane

##### Well-Known Member
I soap warm but still masterbatch my lye. I reheat it a bit before I use it.

I was resistant at first because I thought the maths might be daunting but you only have to do it once for each recipe check it three or four times and you have it forever. Well, at least until you tweak your recipe!

#### Steven

##### Active Member
Required water - half of the 50/50 amount (or the required lye amount, they're the same number and it saves a maths step) is the amount of extra water to put in.
I've read this a few times and I'm having trouble getting my head around it. In the OPs example the batched lye solution is 8.82oz and the additional water is 6.15oz. What it sounds like you @The Efficacious Gentleman are saying is that half of 8.82oz is the amount of additional water to be added which would be 4.41oz, not 6.15oz. Which in my limited understanding would be a different lye concentration that the originally intended 33%, correct? Am I missing something obvious?

2