Teach Soap

Hello,
I have been making CP soap for just a few months now with (mostly!) good results, and am beginning to formulate my own recipes using a good soap calc. I am wondering if anyone knows of the best or ideal percentage for water as % of oils, as well as the lye concentration (%). The soap calc recommends 38% water as a safe bet, but I am wondering if more experienced soapers strive for a different number? Also, is there a range for lye concentration? Seems all of mine are between 25.75% and 29% lye.

Any suggestions would be appreciated. Thanks!

It really depends on your formula and if you are using behaving fragrances. I do a 40% lye solution for plain castille, but back off to 38% for my regular formula. You will need to find what is ideal for you.

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Irena
Closed minds are like faulty parachutes; they refuse to open.

Libby, thanks for asking...this has been a question floating in my head since January, which is when I changed from using soap calc to the soapmaker 3 program. Water percentage and lye solution strength(concentration) are dependant on each other? Is this always the same? Like 27% lye concentration is 36% of water.

Libby, to answer your question I have used mostly 38% water, but every now and then I dropped it to 36%. I am sure that was to experiment or if I wanted a little less water to have to dry out from my bars.

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Susie
Sometimes A Mistake is so much fun, You just have to do it again!

I usually use 38% water unless I am doing castille, then I do a 10% discount.

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~~Heather~~
Mad [soaping] Scientist

if you have ipad or iphone you can try this "soap calc pro" it's has autobalance function. It's calculate different variants of your recipe and show you best one.

Having tried the 'normal' amount of water in soapcalc I find it to be way too much, the bars noticeably show shrinking.

I have a bar of soap that I have been monitoring for shrinkage. It was born on 9-29-11 and at time of unmolding one day later weighed 4.73oz. I used a lye concentration of 28%/ water percentage of 36%. This bar of soap had continued to loose weight until this month. On the 27th of Feb (and the same on 3-26-12) this bar weighed 3.77oz. That is a reduction of 20.3%. This is more than what I had expected. So I am starting to study the water amounts and decide what might be better. I have also switched to the soap maker 3 program which changed up how I recored the amount of water requested... made me have to study this. I will continue to weigh this bar of soap for the next 2-3 months to see if it has really stablized. So why should I even care? Well if I lable the soaps at time of cure this soap would have weighed 4.06 oz; I would have put 4oz on the lable... but that is now less than what it really is/would have been.

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Susie
Sometimes A Mistake is so much fun, You just have to do it again!

Thanks for the useful information. I applaud your use of scientific method.

From you I take that as a great compliment !

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Susie
Sometimes A Mistake is so much fun, You just have to do it again!

Libby, as I understand it, water % is the weight of water with respect to your oil weight.

Lye concentration is the weight of lye with respect to your water.

So a 50% lye concentration would be a 1:1 ratio of lye:water. This is the highest you can go and have all the lye dissolve and it's dependent upon your water temperature (cooler water absorbs less).

Some very experienced soapers use a lye concentration of 40% or even higher as their default.

I am not that experienced so I generally use about 33-34% which works out to roughly as a 1:2 ratio of lye:water. That cuts back on shrinkage but is still generous enough if I want to swirl. If I'm using a misbehaving fragrance or need more time for some reason, I up the water.

For castille, I use 40% lye concentration.

Hope this helps!

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These conversations stimulate more questions. I am wondering if adding beeswax to your recipe will slow down the water weight loss? I don't use beeswax but thought I'd ask this question as it just popped into my head.

I have the soapmaker program and haven't even tried to figure it out yet! LOL

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~bytheSEAsoap~ Mella bythesea, bythesea, bythebeautiful sea

海の皂

I use beeswax in almost every batch and the bar still shrinks about the same as non-beeswax batches I've made.

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Irena
Closed minds are like faulty parachutes; they refuse to open.

The next question would be - if I lowered the water weight the percentage of weight loss should also go down. This is based on that fact that there is less water in the bar. Of course I would have to have a FO\EO that I knew would not cause me grief. My next batches are going to be fruit (for the summer) so I could go with minimum water and check out one bar over the next 6 months. So the challenge is on!

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Susie
Sometimes A Mistake is so much fun, You just have to do it again!

Minimum water is fine, just make sure that you don't use accelerating FO or EO and run it through a lye calc.

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Irena
Closed minds are like faulty parachutes; they refuse to open.