As I discussed in an earlier post, I’m often asked, “what do you do with all of your soap scraps?” Sometimes the result can be very, very beautiful. However, the most correct answer is, “it depends.” Some soap scraps are beautiful additions to new soaps. Others, however, have a different fate.
I’m going to show you a soapmaking project that you can do yourself! No worries… the lengthy instructions belie the absolute simplicity of the project.
Rebatching is a fun way to transform ugly odds and ends of soap, otherwise destined for your garbage, into perfectly usable, cool-looking soap. There are as many methods are there are soapmakers, but this is what I find to be easiest.
Please note that this process can only be done with REAL soap. Save your Sarva Soaps scraps, or any other handcrafted or “true” soap. Detergent bars or “moisturizing bars” or the like are NOT soap (and aren’t biodegradable!). If the ingredient label lists “sodium hydroxide”, or says “saponified oils of…”, then you’re good to go.
Tools:
- food processor with grating blade, or a hand grating tool
- a “soap mold” (some ideas: small cardboard or wooden box, clean milk carton with one side cut off, or a glass baking dish without a lid )*
- parchment paper to line your mold
- glass baking dish with lid (the lid is important) (and if you use a glass baking dish for your mold, you need a separate one with a lid too)
- bowl or bucket to collect soap scraps
- bowl or bucket to hold soap after you’ve grated it
- oven
- stainless steel spoon (MUST be stainless steel!)
- stainless steel blade (MUST be stainless steel!)
- time and patience (this is best done over a weekend)
*Alternative mold idea: Silicone ice cube or muffin “tin” – you don’t need to line it! But please don’t use it for food after you’ve used it for rebatching.
Ingredients:
- soap scraps (for personal use, it is fine to save scraps from used soaps, but for my purposes, I rebatch only clean, sanitary scraps that have been in long-term sealed storage)
- water (distilled is best, but tap will do)
- optional: essential oils (or fragrance oils if you are so inclined; I personally do not use synthetic substances)
- optional: milk (cow’s milk works best but is not vegan; substitutes are coconut milk or soy milk)
Procedure:
1. Collect all of your scraps of soap. I suspect you’ll have a lot less than I do!
2. Run scraps through your food processor with the grating blade in place. I use my studio’s food processor, which is dedicated solely to soapmaking. But it’s okay if you use your own kitchen food processor as long as your soaps are for personal use. Just be sure to soak it until all of the soap rinses off, then wash it thoroughly. You may also use a hand grating tool. You’ll end up with grated soap, below:
3. Add water to moisten your grated soap and stir it with your hands to distribute. How much water, you ask? Um… I eyeball it. Not a lot. Enough to make it a bit slick, but you don’t want to start sudsing your soap or have pools of water in your container. Even if you add too much, it’s okay. The worst that will happen is your rebatched soap will take longer to harden. Maximum amount would be 1/4 cup total liquids (water plus milk) to pound of soap. If you’re adding milk, wait until you are just about to put the soap in the oven. Don’t let the soap sit out overnight with milk in it! (Sorry, no photo here)
3a. Cover your shredded soap and let it sit, ideally overnight. This lets the water sink in and soften your scraps.
4. Here’s the “quick and dirty” method to deciding what size mold you’ll need: Take your grated soap and pack it into the mold you have in mind. See if it fits, maybe overflowing a bit. Does it work out? Great, you have your mold! No? Find a different one!
Here’s my method: I weigh my soap shreds on my soapmaking scale. Since I know how much soap (in pounds) each of my molds yields, I can easily choose a mold. In my case, I have about 15 pounds of scraps this time around.
You’ll need to line your mold completely with baking parchment. I didn’t take a photo of this step – everyone has their own method.
5. When your grated soap is softened (just a little squishy), turn on your oven to about 200 degrees. Pack the soap scraps into the lidded glass baking dish. Put the lid on, and put your soap in the oven. Don’t leave the house, don’t take a nap, don’t forget about your soap! Plan some meals, read the paper, have a cup of coffee with a loved one, do a puzzle… enjoy time in your kitchen, what used to be the center of our homes. Dawdle! It’s a lost art.
Check your soap now and then. Take it out and stir it with your stainless steel spoon every 20-30 minutes. Oh dear… it looks like shreds of soap in some really weird mashed potato-like gel! Yes… that’s good! And after a couple hours (give or take; this is not a scientific process), despite the funny smell (hey, it’s cooking soap), nearly all of the soap will be “gellified”, like below:
You can let it get really gellified if you want, but you must watch it carefully so it doesn’t boil and make a mess of your oven. I like to keep it “less gellified”, because then I still see little flecks of color in the finished product. I took mine out of the oven at this point.
5a. This is where you’d add any fragrance or essential oils. Your first time, I suggest you don’t add anything. But once you get comfy with the process, you can add about 1 tsp or so of scent per pound of soap. Stir thoroughly! (side note: you can “superfat” by adding extra oils too, if you want, such as almond, olive, or castor… add only 1/2 tsp per pound of soap)
6. Glop the soap into your mold. Glop really is the best word.
Now, because I care about you, I must warn you. This is HOT. It was in the oven for a couple hours, it holds heat, it’s gooey like candle wax, and it’s HOT! I know… I know… it’s obvious. But it’s easy to just think, “oh hey, soap” and forget that it’s HOT!
Put on an oven mitt, put a piece of parchment over top of the soap, and press it down, down, down so that it packs into the mold. Otherwise you’ll get big air gaps, and that looks funny. Take out all your frustrations on your poor soap. It can handle it. But you must work fast!
I ran several molds of this size over an extended period of time, so here’s one of mine:
7. Let this cool for several hours… or overnight is fine… and cut into slices, chunks, whatever you like. Use a kitchen knife or any clean stainless steel blade. It doesn’t have to be sharp. I used my super fancy industrial soapmaker’s slicer, and here’s what I got:
8. When you first slice it, it will be a bit soft. No worries. Let it harden for at least 1-2 weeks, maybe longer. It’s usable right away, but the longer it hardens, the longer it lasts.
Cleanup: Be sure to soak all of your dishes, spoons, etc., for a long time in water. Once the soap has softened and rinses right off, just wash everything thoroughly. If you do this often, you really should dedicate a set of utensils and bowls specifically to this task.
9. Use and enjoy! And save the scraps from these soaps, because you can keep on rebatching.
Since I accumulate so many scraps, I routinely donate my rebatched soap to the local homeless shelter association. This time around, I had enough to make about 130 mini bars for them. Our homeless shelters are very much in need these days. While I don’t recommend you donate your rebatched soap (because it’s made of used soap scraps), do please consider contacting your local agencies to see what they need, be it supplies, a donation, or even the gift of your time. If you’re like me, it’ll make your spirit smile.
Be well!
