How much does a soap shrink? My mold is 3.5” x 3.5”, and the boxes I’m considering for packaging are 3 1/16” x 3 1/16”. I’m wondering if after curing they will fit. 30% lye solution.
Soap Shrinkage?
- Thread starter TashaBird
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It's going to take a few years for your soap to shrink almost a half inch on all sides. Either go with a smaller mold or a larger box.
I thought it shrank more than that during the cure. Thanks for the answer! I’ll look for a larger box!
Hi, some of mine. Look like juice boxes, with the air sucked out of them. Side are concaved. But overall size is still the same.
Wow! That’s interesting. Mine are usually the same relative shape.
When I decided to go with boxes, I ordered a few each of different sizes and colors. Little spendy, but it’s better that order 500 0f something you can’t use or don’t like
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This is an indication that you are using too much water in your recipe.
I cut my bars 1-1/4" and they typically shrink to 1-1/8" with a 33% lye concentration. A few years ago I was using 25% lye concentration because my recipe doesn't warp as it ages [and accelerates wickedly], my dimensions were about the same. As I learned to manage a fast moving recipe, I've gradually increased my lye concentration over the years and haven't noticed much variation in size.
Yes, those bar s were made with the default settings in soap calc. Using way less water these days. 
