Leftover Soap Hacks

What to Do with Soap Shavings and Leftover Soap

Leftover Soap Hacks

Reading Time: 4 minutes

What can you do when you have leftover slivers of used soap, or cut off scraps and heels from soap loaves? These leftover soap hacks will help you to use up every last morsel of your handmade soaps, leaving behind no waste and a variety of creative effects. Leftover soap hacks include recipes for milling or rebatching soap, ideas for embedding soap, and tips for using up the last slivers in your soap dish. If you’ve ever wondered what to do with soap shavings, or what to do with soap scraps, adding them as embedded pieces in a fresh loaf of soap batter can create beautiful decorative effects. Enjoy these leftover soap hacks and learn to get every last bit of use out of all of your soap.  

How to Make Soap Out of Old Soap Bars 

When you use up a piece of soap, the last thin sliver is often the most fiddly and difficult to use. Many times, this last bit of soap is discarded for the sake of convenience. This is not necessary  every last piece of your handmade soaps can be not only useful but beautiful. Slivers of colorful soaps can be embedded whole in soap to create a lovely striped effect, or they can be chopped into pieces for other abstract designs. Saving and milling – or shredding, leftover bits of soap is not only economical and waste-free but a pleasant creative process. Shredding leftover soap and molding into balls to drop into soap batter can create a fascinating “planets” effect in your soap loaf. Or simply use the shredded soap as is by mixing with fresh soap batter for a lovely flecked or marbled effect.  

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Shredded soap, formed into balls, make “planets” in this soap. Photo by Melanie Teegarden.
Sliced planets soap. Photo by Melanie Teegarden.

Milling or Rebatching 

Milling, or rebatching, soap is the process of shredding it, melting, and remolding for use. This process allows the last bits of water to escape, creating a rich lathering and mild final result that is very dense and long-lasting. In French milling, soap is shredded and then pressed through rollers to create a thick paste that is then industrially pressed into bars for use. At home, we do not have industrial rollers, but we do have crockpots. With the crockpot, it is easy to melt down the rebatched soap in order to pour it into molds. This is also an opportunity to change the color of the finished soap or to add skincare or botanical ingredients to the soap. Rebatched soap takes very little fragrance for proper scenting, for instance, so using an unscented base and then scenting the rebatched soap can save a lot of money on soap scents and essential oils.  

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Rebatched soap scented with black pepper and sandalwood essential oils. Photo by Melanie Teegarden.

Rebatched Soap Recipe 

  • 3 lbs. plain or salvaged soap pieces, shredded with a cheese grater 
  • 0.25 -0.50 oz. cosmetic-grade fragrance, optional 
  • Up to 0.50 oz. wet additives, such as yogurt or herbal infusion, optional 
  • Up to 0.50 oz. dry additives such as herbal powders or clay, optional 


Add shredded soap to a crockpot set on low heat. Add wet additives, if using. If not using wet additives, you may need to add 0.25 oz. plain water to the soap to encourage melting. Don’t overdo the water! Cook until melted into a paste, approximately two to three hours, stirring occasionally. When melted into a consistent mass, remove from heat and stir in dry additives and fragrance, if using. Start out with 0.25 oz of fragrance and mix well before deciding whether or not to add more this variety of soap does not require much scent. Pour into a loaf mold or into individual molds. When cooled, it is immediately ready to be sliced and used. Do not use a wire cutter to slice this soap from a loaf the strings may break; it is very hard. Use a long, non-serrated knife or a dough cutter to slice the soap into bars.  

Something from Nothing 

Using up every last sliver of your handmade soaps is a gratifying experience. To be able to put every bit of your effort into a usable product means a lot. Not only that but with a simple knife or cheese grater, you can transform a couple of bars of plain soap into a beautiful abstract design element in a fresh batch of soap batter. Cubes or spheres of soap can be dropped into soap batter for pleasing effects. Try complimentary stripes of soap heels in a neutral base of plain, scented soap. Soap balls in varying sizes (or all the same size) make a lovely slice of cold or hot processed soap even more special. Even shredded soap can create a lacy coloring effect in your soap bars. Try combining colorful soap swirling techniques with embeds for an extra special soap. Top a rich coconut-scented soap with shreds of white soap for a completely useful embellishment. When it comes to rebatching, this is an excellent way to maximize the impact of your precious and expensive fragrances and essential oils. Since the soap is fully saponified, it takes very little of the fragrance to get a lasting effect.

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Leftover soap slivers form tree trunks in this soap. Photo by Melanie Teegarden.

These leftover soap hacks should help you use up every last bit of your soap in a pleasing way. Will you try rebatching or embedding soap shapes? Please share your results with us!  

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