Figuring out lye amount

Regalitofatal · Jun 6, 2017

Oh hello there, it's me again. Trying a new batch of liquid soap and proud to say it doesn't stink!! (Funky Smell thread)

This time I did not cook the liquid paste and have let it sit overnight. It's been 24 hours and my paste is golden amber, smells delicately nice, but is not passing the zap test.

I don't mind waiting but I thought after 8 hours it shouldn't zap anymore? Stirring doesn't make a difference does it? Makes me wonder if I used too much lye.... Which leads me to my next main question

When using SoapCalc for liquid soaps, what should the water as % of oils be? It defaults at 38% but the first liquid soap I ever tried to make had it at 80% and does this even change the amount of lye anyway? I tested my recipe with three different lye calculators and got 3 different answers. :-?

I used:

10.4 oz Olive Oil
4 oz Coconut Oil
1.6 oz Castor Oil

SoapCalc told me to use 2.32 oz KOH + 12.8 oz water
Summerbeemeadow told me to use 3.43 oz KOH + 10.29 oz liquid (4 oz was glycerin)
Brambleberry told me to use 3.39 oz KOH + 10.4 oz liquid

The difference in the amount of lye between SoapCal and the others concerns me

I used Brambleberry since it was pretty close to SBM and made me feel more confident in the calculations. Did I do something wrong on SoapCalc?

All of your help for this curious and determined newbie is much appreciated

DeeAnna · Jun 6, 2017

I would double check the recipe you entered into Soapcalc -- the KOH amount does look out of whack. It might just be that you accidentally typed a number wrong. The other two are close enough that makes never-no-mind.

I don't use "water as % of oils" because this setting causes trouble in the long run, especially if you make a lot of different types of soap. I recommend instead to use either lye concentration or water:lye ratio. These two settings are equivalent to each other. I use lye concentration and for KOH soap, I set it to 25% lye concentration. You can set the water:lye ratio to 3:1, and that means the same thing.

My KOH soap is usually zap free in an hour or so, but I make sure my soap batter is warmed to 170-180 deg F at the beginning. This jump starts the saponification reaction so it gets going well. Once going, the saponification will keep the soap paste warm enough on its own to get the soap finished up quickly. If your starting temp was fairly cool, saponification will take longer.

I don't normally stir a lot, but there's no harm in stirring once in awhile.

At this point, the simplest thing I might try is to give the soap paste a good stir, wait another day, and zap test. If you're impatient, you could carefully microwave the paste to warm it to that 170-180 range (heat for a bit, stir, heat for a bit, stir, etc.) Once warm enough, cover it to keep the warmth in, let it sit overnight, and retest.

IrishLass · Jun 6, 2017

If it were me, I would just let it sit (covered) a couple of hours longer or overnight and check for zap again. It should definitely be zapless by morning.

Re: stirring- if it is a paste- no need to stir it (not that it would be very stirrable anyway

).

I always use SummerbeeMeadows calculator whenever making liquid soap. Their default water amount happens to be a 25% lye concentration (1 part lye to 3 parts water), which is the perfect about for making hassle-free liquid soap paste, and I always have great results with a superfat of 3% on their calculator, even when the purity of my lye has been unknown. For what it's worth, though, I think their calculator is set for a 94% KOH purity.

Using SummerBeeMeadows as a comparative guide, your water/lye amounts using Brambleberry turn out to be about a 3% superfat and just a teensy titch below a 25% lye concentration on SummerBeeMeadows calculator. As you said- pretty close!

When using SoapCalc, there are 2 ways to figure the lye amount- either via the 'lye as % of oils' box, or the 'lye concentration' box. For more precise accuracy from batch to batch, never use the 'lye as % of oils' box. Always use the 'lye concentration' box. We have numerous threads on the forum explaining why it is best to use the 'lye concentration' box instead. I'll see if I dig up one of them and post a link to it. In the meantime, if you ever try to use soapCalc for liquid soaps, make sure to click on the 'lye concentration' box and type in 25%. Don't pay any mind to the 'lye as % of oils' box. Just leave it alone/ignore it. Also- make sure to click on KOH and 90% purity.

I'm off to go look for a link.......

Edited to add- looks like DeeAnna and I were posting at the same time! :lol:

Edited again to add the link: http://www.soapmakingforum.com/showthread.php?t=53642

IrishLass

Susie · Jun 6, 2017

Go use Soapee.com for everything and stop running your recipe through multiple calculators. You can drive yourself crazy doing that! (Ask me how I know...)

Use a 3:1 ratio for the water to KOH.

Use the appropriate purity for your KOH.

Set it for 3% superfat or lower.

Plug in the correct amounts of oils.

Let the calculator do the rest.

I get KOH-3.55 oz and H2O-10.64 for 3% superfat.

So, according to my calculations, zap should be the least of your problems. Did you mis-type something?

Regalitofatal · Jun 7, 2017

Susie said:
Go use Soapee.com for everything and stop running your recipe through multiple calculators. You can drive yourself crazy doing that! (Ask me how I know...)

Actually I'm glad I ran it through multiple calculators. Otherwise I would have used 2.32 oz of KOH from SoapCalc and not questioned anything

Using the proper lye % on SoapCalc, I'm now getting the correct lye amount for my liquid soap. That was the issue. Will not be using "water as % of oils" anymore. Thanks everyone!! I'll be checking for zap in a few hours after work

Regalitofatal · Jun 12, 2017

Well, when I got home it passed the zap test but to my disappointment, it is completely cloudy after I diluted it. I diluted with 100% distilled water, 50% of the soap paste's weight to start and a little extra afterwards due to the thickness. It was cloudy as soon as I poured the hot water. Not sure what I did wrong but I'll keep practicing