Best Lye Calculator for Liquid Soap

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Mar 27, 2011
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Northern California
Good afternoon. I have planned on making another batch of liquid soap this week, so I went to Summer Bee Meadows lye calculator at and lo and behold, it's down and not available. I have some older recipes that I can use again. I've run these recipes through several other lye calculators (SoapCalc, Brambleberry, etc) and get significantly different water amounts. I guess my question is twofold: 1) which lye calculator is best for liquid soap making, and 2) why would the water amount so different between sbmcrafters and other calculators. Any assistance would be greatly appreciated. Thanks
Pretty much any soap recipe c@alculator can be used to calculate liquid soap recipes, as long as it allows you to choose KOH as the alkali. SBM advanced calc is one, but Soapee Next and SoapmakingFriend calcs are two others.

You didn't provide any recipes as examples from the various calcs you've tried, so I'm guessing here.

A common reason why a person might see variations in the water content is you're accepting whatever the default water setting is for each of the calcs you've tried. Different calcs use different defaults.

I recommend you set the lye concentration to 25% (this is NOT water as %of oils, by the way). See if that gives you more consistent water amounts.
1) which lye calculator is best for liquid soap making
I use SoapCalc. Water to Lye Ratio: 3:1 (typed in) Here's how I set it up:

KOH in LS.png

I've been using the 3:1 water to lye ratio ever since I first made LS in 2004. When I resized all of Catherine Failor's recipes, they were all like that. I've made LS successfully with 2:! but there you risk the batch bloating up and over the container faster than you can blink. :D
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Thank you for your reply. As I investigated further, I noticed that the default for the lye concentration was something other than 25%. When I change this default to 25% and water to lye ratio to 3:1, I was able to recreate the values in my original Summer Bee Recipes.

Thanks again for taking the time to help with this. What a great resource you folks are!!!

I guess I will be making a batch of soap this week after all.
Lye concentration of 25% is the exact same thing mathematically as a water:lye ratio of 3:1. Pick one of these settings, whichever one makes more sense to you, and use it consistently. You don't have to enter values for both.
I have a question for you guys who prefer SoapCalc for ls: are you mixing the lye in with glycerin, or water?
I use glycerin which everybody knows is more energy-intensive to mix lye into than water, & there's so much less water in the SoapCalc recipe I'm not comfortable with it
BB Lye Calc has never let me down and you guys are saying use SoapCalc, but SoapCalc wants me to cut almost in half the water content, and decrease the lye percentage.
Can somebody please enlighten me WHY an experienced soaper should cut the water content on ls from the 60.38% BB recommends to the 33% to 38% SoapCalc says I should be using?
I have paste stored using the BB recipe that's still good after many years; indeed, none has ever gone bad on me.

I need to whoop up some ls before my glycerin & lye expires, so I'm comparing the recipes on BB Lye calc versus Soapcalc.
I want to make a simple 100% coconut oil (100 oz oil) ls w/ 0% sf.
Here's differences:
1) Water content- BB Lye calc says use 60 oz of water or glycerin and SoapCalc says to only use 38 ounces.
2) BB says use 27 oz of lye whereas SoapCalc says to only use 25.7 oz- i always thought the 0% sf ls recipe from bb lye calc needed, if anything, more rather than less lye bc there seems to be a bit of cream in the glass mason jars after sequestration and storage.

Why should an experienced soaper should be using the latter recipe from SoapCalc rather than the former recipe from BB?


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