Water as % of oils question

[Shannon WY]

I've been using a 3 oil recipe (great beginner recipe) out of a soaping book I bought. It calls for 8 ounces of water and 4.2 ounces of lye. When I ran it through soap calc, water as a percent of oils is 26.75 (lye concentration 34.7%). The calculator has a standard 38% water as a percent of oils, so running the recipe through with that, it shows I should be using 12.16 ounces of water and 4.56 ounces of lye for a lye concentration of 27.52. From what I've been reading, when the lye concentration is 40% it is considered lye heavy. Do any of you use a recipe with this high of a lye concentration?

[Carrie]

Yes, when making unscented soap.

I typically use a 33% solution. That's 2 parts water and 1 part lye, or 1/3 of the solution is lye, hence the 33%. When I'm making a batch of soap with no FO to speed things up, like Castille, I've used even higher percentages.

Thinking about the "lye heavy" statement. It makes me wonder...How much water does lye need to fully dissolve? Will it fully dissolve in a 50% solution or is that what you mean by a 40% solution being lye heavy.

[RobinInOR]

You can get lye to dissolve in it's weight of water, but that's kind of iffy and about as far as you can go. I use a 40% lye solution most of the time. Use the term "lye heavy" when you mean you used too much lye for your oils. A 40% lye solution is a stronger lye solution than 'usual'. A 50% solution is as strong as you can get unless you really work at it.

Don't mix up your amount of water vs oils and your lye vs water. Lye is based on oils, that's all. You can calculate water either against the oil amount (what calculators such as MMS do), or the lye amount.

[Shannon WY]

Thanks for your help- I played around with the soap calc some more and it makes much more sense now. I was trying to understand why 38% was the default for the water as a % of the oils. On the Soap Calc's FAQ page, it states

"The calculator has a default value of 38%. It's a safe starting point and will make a decent bar of soap for both CP and HP. You can experiment from there. Caution: Lye solutions with higher concentrations of lye will speed up the chemical process. Your oil and lye solution mixture could easily bubble out of the pot and spill over your stove or table (or you). This happens quickly. It is commonly called the volcano effect. Beginners should start with the default 38% "Water as % of Oils"."

When I found out the recipe I was using was quite a bit less than they recommended (27%), I was a little concerned.

I see where I confused the term lye heavy - I had put in 41% as the lye concentration (my recipe is 34.7%) and got the pop-up window with the caution statement that the lye is greater than 40% of water and lye solution. So much to learn:)

[RobinInOR]

It's pretty confusing at first. That pop up window is just a safety one, to warn you that you're working with a more concentrated lye solution, so you better know what might happen.

"Discounting water", using less than "usual", can cause all sorts of problems, like the faq page stated. It's much easier to learn what's going on in the reactions if you use the larger water amount. Your soap will be softer and take longer to harden up, but as you get more familiar with the process you can start dropping the amount of water down in small steps until things start acting badly.