Do you let your M&P "cure"?

[sstorelli]

Do you let your M&P sit for a bit after unmolding to "cure"? Just curious if it may harden up the bar, therefore maybe making it last longer.

Thanks!

 

[squigglz]

M&P isn't like CP. The glycerin used in the base is a byproduct of CP soaping, and thus behaves differently. If you allow it to 'cure' for too long, it will shrink way too far and become crumbly. MP should always be shrink wrapped or otherwise stored in an airtight manner. If you're talking 24 hours or whatever, that's probably fine, but there's no benefit and many possible drawbacks.

 

[Genny]

I actually do let mine sit out in the air for a few days. But I live in a dry climate. It also all depends on what MP base you are using. Some will sweat like crazy if left out and get any humidity on them. Some get really dry. But some do just fine.
I've found some of my old MP soaps, like 3 or 4 years old, and they were left unwrapped and definitely lasted longer when we used them since the excess moisture had dried out of them.

Also, the vegetable glycerin used in MP bases is not a byproduct of CP soap. It is created by hydrolysis (extraction) of the vegetable oils' crude glycerol fats. Basically, the oil is heated to a high temperature of above 400 degrees, under pressure with water. The glycerin splits off from the fatty acids, and is absorbed by the water. Then it is distilled to remove the glycerin.