How to Keep Homemade Soaps From Sweating | eHow
Homemade soap will often sweat after curing for several days. Because the soap is high in glycerin, it will attract water, which will show up as small droplets on the surface of the soap. This happens in humid conditions. Although the droplets are a sign of a high-quality soap, they can cause the oils in the soap to go rancid faster than normal.