soap caves in when cooling?

[soapshark]

I have been making the same HP recipe for awhile and using cardboard boxes as molds and never had any issues. Now I went and bought some professional silicone loaf molds that are roughly the same size as the boxes, but I'm noticing that when I fill up the molds to the top, after an hour or two they've caved in in the middle leaving this weird valley down the center.

what the heck? how can I keep this shrinkage from happening? I've tried even putting extra soap on top in the middle (make a little mountain) hoping it will even out when it cools, but it doesn't always work. gaahh! why is this happening? How can I keep this from happening? I want it to be perfect on top

thanks!

 

[IrishLass]

Could it possibly be that the flexibility of the silicone mold is causing it to bow outward somewhat from the weight of the soap (some have reported the bowing problem), which in turn is causing the middle to sink?


IrishLass