# water to lye or fat ratio



## athertm (Jan 15, 2010)

Hi, we are about to make out first batch of soap this weekend and I'm happy that I understand the lye to fat ratios working on the sap tables for the fat/oils we are planning to use. My question is regarding the quantity of water to use. I've seen a number of recommendations stating a .38 water to fat ratio and others stating a 27/73 parts lye/water ratio both return a value within 60ml or so of each other for a batch of soap containing just over 2kg of fat. Does anyone have any advice on working out the correct/best/easiest way of working out the amount of water to be used, and what the affects of using too much or too little water may have.

PS. How much essential oil would be the norm to add for this amount of soap. I think a combination of 2 oils will be used to keep it simple.

Many Thanks.


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## honor435 (Jan 15, 2010)

do you use the soap calc? it is very easy, i could never figure out the ratios with out it! I usually do 7% superfat, 33% instead of the 38 default for water. does that help?


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## Deda (Jan 15, 2010)

I use a lye:water ratio for all my soaping. 

I don't let the oil weight dictate the amount of water.
Try figuring your water based on how much lye you need.


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## IrishLass (Jan 15, 2010)

Exactly what Deda said. I don't calculate my water amount based on the oils either. I base it on my lye amount (using a 33% lye solution, normally). Here is a lye solution strength chart:


Solution Strength chart
Lye x 1.0 = 50% lye solution (the absolute limit; not recommended, esp. for newbies) 
Lye x 1.15= 46.5% lye solution
Lye x 1.2 = 45.45% lye solution
Lye x 1.25= 44.44% lye solution
Lye x 1.3 = 43% lye solution
Lye x 1.4 = 41.66% lye solution
Lye x 1.5 = 40% lye solution
Lye x 1.6 = 38% lye solution
Lye x 1.7 = 37% lye solution
Lye x 1.75= 36% lye solution
Lye x 1.8 = 35.7% lye solution
Lye x 1.9 = 34.5% lye solution
Lye x 2 =    33% lye solution (a very good, general lye solution amount; my fave) 
Lye x 2.1 = 32% lye solution 
Lye x 2.3 = 30% lye solution 
Lye x 2.7 = 27% lye solution 
Lye x 3.1 = 25% (considered a 'full water' amount by most lye calculators)

Basically, what this chart is saying is that if you want to use a 33% lye solution, for example, you would be adding twice as much water as lye.

I hope that helps!
IrishLass


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## athertm (Jan 16, 2010)

Many thanks. We'll use the 1 lye to 2 parts water (33/66) rule for the first batch. I'll be sure to post back with the results. I think we now have the basis for a generic CP base. It's just a matter of putting it in to practice  :? Thanks for the replies and thanks to IrishLass for the strength chart. I'm sure we'll experiment with other ratios once we have a solid baseline to work from.

Well here goes ........


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## kbn (Jan 18, 2010)

I'm almost embarrassed to ask this question, but here goes anyway: When using the soapcalc lye:water ratio set at 33%, if you use premixed lye how would you then measure out the proper amount?  Would you add together the weight of the lye and weight of water and measure out that much?

I'd like to mix up a bunch of lye to have it ready but had no idea what to do next! Sorry to hijack the thread and thanks in advance for any help.


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## Deda (Jan 18, 2010)

Lye @ 33% based on using 33g lye:66g water

You've premixed your lye with 50% water.

Suppose your recipe calls for 150g lye and 300g water.
Use 300g of the premix and an additional 150g water.

Recipe calls for 225g lye and 450g water?
Use 450g of premix and an additional 225g water.


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## kbn (Jan 18, 2010)

Thank you so much Deda!


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## kbn (Jan 18, 2010)

Ok, one more question- is there any benefit to mixing up a 50% lye solution over a 33% lye solution? Unless I'm misunderstanding it seems as though the method you explained is the same thing as mixing up a 33% solution and then adding water and lye rates and using that much of your solution.  Thanks again. :-D


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## IrishLass (Jan 18, 2010)

I make a large master-batch of 50% lye solution all the time for use over an extended period of time (saves me from having to mix my lye solution from scratch each time I soap). I store it in a heavy-duty HDPE container with a tight lid (an ALL detergent bottle). When I want to soap, I just pour out the proper amount of solution as per my calculations (see below) and I dilute it to the proper concentration (i.e 33% or 27% or 40%) depending on the batch I'm making. 

Why a 50% masterbatch as opposed to a 33% master-batch?: Although I mostly soap with a 33% lye solution, I have a few batches that I do differently based on the FO and the particular recipe I'm making. Sometimes I use a 27% solution and sometimes I use even a 40% solution. In these respects, master-batching a 50% solution as opposed to a master-batch of 33% solution works better for me because the math is much is easier to calculate when trying to figure out how much more water to add when it's being calculated from a 50% solution as compared from a 33% solution.

Here's my simple calculation to convert a 50% master-batch of lye solution to any batch, no matter if your batch calls for a 33% solution or a 25% solution, etc., etc.,. This math equation works the same across the board. Just enter your recipe as you would normally do into one of the online lye calculators, including your superfat amount, preferred lye concentration % (33%, 25%, 35%, etc., etc., - or whatever level you like to soap at). Then apply the following equation to the lye and water amounts that your lye calculator gave you:


- LYE:  Your total recipe amount of lye multiplied by 2 equals how much of the 50% lye solution you need to weigh out for your batch.  

-WATER: Your total recipe amount of liquid minus half of the 50% lye solution you just  weighed out equals how much more liquid to add to your batch.

HTH!
IrishLass


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## kbn (Jan 18, 2010)

Irishlass, that is a tremendous help! Thank you for taking the time to explain it so well. I really appreciate your time and expertise. It makes perfect sense now!


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## IrishLass (Jan 19, 2010)

Glad to be of help.   

IrishLass


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## xyxoxy (Jan 19, 2010)

I'm a little late to this party but I just want to echo how easy it is to use a 50% pre-mixed solution. I also do this just as IrishLass described... down to using a laundry detergent bottle for storage. I also pre-mix in some tussah silk into mine and use aloe juice... but the end result is a 50% lye solution.

I almost always use a 33% solution in my batches though some require slightly stronger or weaker solution and I adjust accordingly. But at 33% I can just swap the soapcalc lye/water amounts in my mind and that gives me the amounts for the 50/50 solution and my additional liquid.

Ex: Soapcalc says to use 50g lye and 100g water. I measure 100g 50/50 pre-mix (which has 50g lye and 50g liquid) and then I measure 50g additional liquid.

Hopefully that doesn't make it sound more confusing than it is... it is very simple and also benefits those of us who like to soap at room temperature.


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## Soapman Ryan (Apr 17, 2013)

Why would you want to change the lye to water ratio? How does this affect the soaps final product?


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## DeeAnna (Apr 17, 2013)

More water tends to slow trace, so if you are using ingredients that accelerate trace, you might want to use more water. Vice versa for slow tracing ingredients, such as castile soap. More water makes a softer bar, however, so the soap may take longer to firm up enough to unmold and longer to dry down. Does this help?


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## Soapman Ryan (Apr 17, 2013)

DeeAnna said:


> More water tends to slow trace, so if you are using ingredients that accelerate trace, you might want to use more water. Vice versa for slow tracing ingredients, such as castile soap. More water makes a softer bar, however, so the soap may take longer to firm up enough to unmold and longer to dry down. Does this help?



Yes, thanks


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## TeriDk (Apr 17, 2013)

IrishLass said:


> Glad to be of help.
> 
> IrishLass



Glad to see you posting again.  You were a major help to me when I first started my addiction...I mean soaping.


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## DeeAnna (Apr 17, 2013)

Ummmm ... the last post by IrishLass in this thread is from 2010. I have really enjoyed reading her posts too.


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## sistrum (Sep 4, 2013)

IrishLass said:


> Exactly what Deda said. I don't calculate my water amount based on the oils either. I base it on my lye amount (using a 33% lye solution, normally). Here is a lye solution strength chart:
> 
> 
> Solution Strength chart
> ...



Here is this also

Well I don't know what I did but I can't delete this post for some reason.  
I guess it won't get lost again for awhile.


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