Black Cocoa Butter Homemade Soap Recipe

Here is a really interesting hot process soap recipe from Skin Naturals. Black Cocoa Butter Homemade Soap Recipe was made in a slow cooker and then plopped into a bag when it was cooled for future batches and adding color. I have heard of making a soap recipe in a slower cooker before but I have to admit that I have never heard of a soap recipe kept into a plastic bag and store for future batches.  Has anyone tried this before?  I would like to try some day but as of now I do not have a place to store it?  My main question is where to store it - in a cool place or what?  Any advice on this?