Soap is cracking when using Sodium Lactate.
by Amanda
(Tip of the Mitt-Michigan)
I've been making soap for a little over a year now, but still consider myself a novice because I don't soap continuously.
I have made both CP & HP soap along with re-batching scraps into a new soap and successfully made a "Mechanics's Soap" that has gotten my father's hands clean for the first time in years. :)
I started using Sodium Lactate in hopes for harder bars, easier to get out of the mold, etc...
The problem is, every time I use it, my soap cracks down the middle on the top of the loaf.
I've tried catching it in time to smooth it out with my hand (using a glove), tried heating it up a little too, but I'm doing something wrong.
I've tried it at both 1% and 3% of my total oil weight and it still cracks.
Any and all help is much appreciated :)
Answer:In addition to making your soap harder and easier to unmold, sodium lactate can also speed up saponification.
When saponification happens rapidly, this usually means that the temperature is rising quickly and will result in your soap reaching the gel phase sooner than usual.
If you normally insulate your soap mold quite well, the addition of sodium lactate may be causing your soap to overheat. When soap overheats, the most common result is a long crack down the center of the soap loaf.
I suggest you use less insulation than normal on your soap mold and check it every hour after you pour.
As soon as your soap gels, take off the insulation and leave the soap open to cool off.
I would also go with the lower percentage per pound of oils to start and see how that goes before attempting a higher amount.
Good luck,
Cathy