Castile Soap troubleshooting

[genevievechl]

I swear, I have made soap before...

Does anyone know why this happened to my cold-processed castile soap? I used this recipe. I have used it before with success but this time, I doubled it by 10 to fill up my soap mold. It's possible when I was weighing out my ingredients, I may have poured a little more or less by accident due to multiplying it by that much. And honestly, there were a few signs that made me think this was going to be a fail. When I poured the lye water in my oil, it bubbled a bit on the surface. I used my hand stick blender, got it to achieve trace and the bubbles dissipated. It looked normal. Then I poured it in my mold and was going about covering it up to trap in the warmth for saponification (something I always do) when it started bubbling! (See attached image). Needless to say, I had to toss it. It was overflowing into my sink. I'm sure somewhere along I did something wrong. Does anyone out there know what would cause this to happen?

Thanks,

 

[shunt2011]

Did you run the recipe through a lye calculator? If not that's probably a huge part of the problem. What temperature where your oils/lye?

 

[DeeAnna]

"...I doubled it by 10 to fill up my soap mold ..."

Uh, this is a really confusing statement. Specifically what did you do -- Did you double the recipe? Or did you increase it by 10 times?

When you increase the size of a recipe, always run it through a soap recipe calculator to ensure the NaOH weight is correct. This avoids any problems due to rounding error or arithmetic mistakes.

More specific to your problem --

Just because you've made the basic recipe before doesn't mean this particular batch was the same as the others! If you think about the differences between this batch and the previous ones and that will often point you toward the source of the problem.

When you increase the size of a batch, the center of the soap will stay hotter due to slower heat loss. Your comment that the lye solution bubbled when you added it to the fats makes me think some of your ingredients were unusually warm to start with -- the lye solution, the fats, or both.

If you had poured this batter into individual molds or a slab mold, it might have worked fine. But since you poured the batter into a loaf mold, the high temperature of the batter caused steam to form in the center. The soap batter expanded in volume and overflowed the mold -- in other words, a volcano.

Soap cooler. Shoot for the soap batter to be no hotter than 110 F.