Lye calc confusion for Liquid Soap

[Wild Vegan]

Hello everyone,

This is my first post here and I have tried out a few CP, HP, solid and liquid soaps.

Now I'm ready to share with friends and family and maybe sell eventually.

I am forever confused with Lye calculators since each gives a different result. I'm trying to make a small batch of liquid soap for cleaning purposes - so 100% Coconut oil with 0% Superfat. Here are the results I got from different Lye calculators online.

Measurements in grams (I'm from India )

So, for 200 grams coconut oil - I chose Coconut oil, 76 degree since it is liquid at room temp. and 90% pure KOH

Soapcalc.net :
Coconut oil - 200 grams
KOH - 57.11 grams
Water - 76 grams

Brambleberry:
Coconut oil - 200 grams
KOH - 54 grams
Water - 120.75 grams

Thesage:
Coconut oil - 200 grams
KOH - 51.6 grams
Water - 50 - 75 ml

Thesoapcalculator :
Coconut oil - 200 grams
KOH - 51 grams
Water - 76 grams

Please help me choose the right calculation. TIA

 

[Obsidian]

Since different calculators use slightly different sap values for the oils, they will always vary some.
Pick whichever calc you like best and stick with it for all your recipes. I prefer soapcalc

 

[DeeAnna]

I'm from Iowa, USA, and I use grams too.

The short answer -- Pick ONE online calculator and use it. Don't switch back and forth and agonize over why there are differences, because this is not going to help you with your soap making.

The long answer -- Every calculator is based on different data and assumptions, so of course you're going to get different answers. For one thing, sap values vary slightly from calc to calc, because real measured sap values vary, since fats are natural products. And assumptions about alkali purity and water content also vary from calc to calc --

I know you didn't set the purity to 90% for The Sage calc because changing the purity is not an option for that calc. The calc is based on 100% KOH purity. I can't speak about The Soap Calculator, but the KOH weight is essentially the same as for The Sage results, so this calc is also using 100% KOH purity.

Brambleberry's calc also doesn't allow the user to change the purity. That one is tailored to be accurate for their products, and their KOH is in the mid-90% range. That's why the KOH weight from the BB calc is between SoapCalc and the other two.

The only calc of the 4 that would let you set the KOH purity to 90% is SoapCalc. That is why it calculated the highest KOH weight. As the purity drops, the weight of the alkali needs to increase to compensate.

Actually a better calc for liquid soapmaking is Soapee because it lets you set the purity to whatever your actual KOH is. Some people can only get 85% pure KOH. Others have 95% KOH. And so on. The new Soapmakers Friend calc here on SMF also allows a person to set the purity.

When setting up a recipe, you need to make sure you're using a consistent basis for the water as well. You need to know your calc well enough to know its default settings for water content and how to change those settings to suit your needs. For liquid soap, I use a lye concentration of 25% (water:lye ratio of 3), which is not a normal default for most calcs. (This isn't "water as % of oils" just to be clear.) See my articles on water in soap for more: https://classicbells.com/soap/waterRatioConc.asp

 

[Zany_in_CO]

So, for 200 grams coconut oil - I chose Coconut oil, 76 degree since it is liquid at room temp. and 90% pure KOH
Soapcalc.net :
Coconut oil - 200 grams
KOH - 57.11 grams
Water - 76 grams

Hello and Welcome to SMF, Wild Vegan!
Hmmm. Coconut oil 76°F is solid at room temp here. ???
So now you understand why soap calc results vary. With LS, as DeeAnna suggested, you have to manipulate the setting to get the correct amount of water.

When I first started making LS in 2007, I noticed that all of Catherine Failor's recipes were calculated with water at 3 X KOH. I later learned that using 2 X KOH brings the batch to trace faster (CAUTION: Not recommended for all formulas because this does tend to make the batch bloat up and flow over the pot.) Generally, 3 X KOH is best for most formulas.

I also use SoapCalc.net. So, for the correct water amount you need to tick "Water : Lye Ratio" and type in either 3:1 or 2:1. For 100% CO I use 2:1 and get this result:
Coconut oil - 200 grams
KOH - 57 grams (rounded)
Water - 114 grams (rounded)
Dilution Rate: 40% soap paste to 60% water

HTH (Hope That Helps)

 

[Wild Vegan]

Thanks a lot for the responses.

When I knew little, I followed soapcalc.net. As time passed, I started reading a lot whenever I was not soaping. This is the bane of over analysing I guess

I will stick to soapcalc.net and get to work. And completely grateful for the Water:Lye Ratio tip

Today is weekend so I begin soaping in some time

 

[KristaY]

Welcome Wild Vegan and best of luck with your LS (liquid soap)!

 

[DeeAnna]

My pardon if you know this one already, but the rule of thumb most of us use for superfatting liquid soap is no more than 3%. Liquid soap typically can't "hold" more superfat than this unless you plan to add an emulsifier to deal with any extra superfat. Most calcs default to 5% and that's usually too much.

 

[Wild Vegan]

Thank you KristaY

DeeAnna, I am aware. I actually set the superfat to 0% since this is primarily used for cleaning.