Soap bars crumbled at base of cut!?

[LynetteO]

My 2 latest soaps, when cut, crumbled a skosh at the base. I haven’t had this happen in about a year & with just a couple batches. I’d love to figure out why & eliminate the cause. Two soaps in two days did the same. 1st batch had sodium citrate, 2nd did not. Here’s recipe details:
Lard (60%), CO (20%), RBO (15%) + castor (5%). SF @ 3% Lye concentration 33%, Aloe Juice as full water replacement. Same FO both times = NS grapefruit bergamot + Lime EO. Ist batch 3% fragrance, 2nd batch 5%. Lye was 110F & oils about 100F. Color: 1/4 tsp mica 1st batch, small amount of dye (pre diluted in H20) in second batch for swirl plus 1/4 tsp TD diluted in 1tsp water dispersed in entire batch to help with discoloring FO. No other additives in 1st batch. 10% pumice PPO in 2nd. 1st batch (right) cut at 24 hours, 2nd (left) cut at 15 hours. Zap test negative

 

[LynetteO]

When pondering this issue & thinking about the last time this happened. It has always been the soaps that I made using 1lb silicone loaf mold from NS. Could be just a coincidence but that is also one thing each crumbly batch has had in common. However, not every batch so probably not the issue.

 

[AliOop]

I too have several molds that seem to result in crumbly and/or ashy soap. I truly think it is some additive in the silicone used to create the mold.

My only other thoughts:

1. you used a lot of citrus FOs/EOs, which are often decelerating. Any chance that the emulsion wasn't quite stable when you poured?

2. Perhaps the pumice wasn't equally distributed, or some sank into that corner? I've had some crumbly spots in pumice soap for that reason.

 

[glendam]

This happened to me a couple months ago, when I switched to new lye. Fresh lye, I should say. I had to increase my superfat (since I wanted to keep my water discount).

 

[LynetteO]

I’m using a brand new batch of lye. The 1st batch could maybe have possibly been poured too soon but definitely not the second. However, not evenly distributed pumice is a distinct possibility in the 2nd batch. Neither batch came out green either, which is a real bummer.

That’s why I make the batches small. I just may have to try for a 3rd time.

 

[Obsidian]

How long after pouring did you cut and what did you use?
Soap that is too hard tends to crumble like that, especially if cut with a knife that has a thicker spine.

Try cutting a little sooner, soap should have give like a young block of cheddar cheese and use a wire cutter

 

[glendam]

Lye loses power over time, so the fresh lye will surprise on how hard it can make a bar of soap. Depending on what your superfat is, you may want to increase it, or cut the soap sooner if possible, or adjust the hardness factor of your recipe.

 

[KiwiMoose]

Not gelled?

 

[DeeAnna]

If you're using a knife to cut the soap, try using a flat blade like a bench scraper (aka dough cutter) or a wire cutter like a cheese cutter. A knife has a triangular cross section that wedges the soap apart. At the bottom of the cut, soap that is more brittle may shatter due to the wedging action of the knife. Going to a flat blade or wire cutter is the solution.