How to Melt Soap & Remold It into a New Bar

If you want to delve into the world of soap making but are too afraid to work with lye, consider making a new soap bar using old bars. Remolding soap allows you to learn the basics of soap making while experimenting with additions, such as oatmeal and essential oil. It’s also a great way to salvage botched soap batches. The process is called "hand-milling" and or "rebatching" soap. We spoke with Arts & Crafts Expert Shelley Williams and Master Herbalist and Certified Aromatherapist Julie Brow-Polanco to help us learn about working with handmade soaps.

How to Melt & Remold Soap Scraps

Grate the soap or cut it into small pieces and heat it with water in a double-boiler or crock pot on medium heat. Mix occasionally until the soap softens. Add any colors, fragrances, oils, or herbs, then press the melted soap into molds and allow to dry for 1 to 2 days before de-molding and using it.

Part 1

Part 1 of 3:

Preparing the Base

Download Article

1
Choose a soap base. Use any soap, but something unscented and natural, such as pure castile soap, would work best. This will give you more options for customization later on. Plan on using about 12 ounces (341 grams) of soap.
- Melting soap and then remolding it into new bars is referred to as hand-milling or rebatching soap, Williams says.
- Rebatched soap will have a grainy texture and won’t be as smooth as a regular bar of soap.
- If you use leftover soap scraps, try to match the same scent. Otherwise, you might end up with a not-so-nice fragrance.
- Mixing colors is fine, but keep in mind that they may not always blend together to form a new color. Sometimes, they may appear as specks or swirls.
The easiest way to do this is with a grater, but mincing or cutting the soap with a knife also works. The smaller the pieces, the faster your soap will melt.

Advertisement
3
Place the soap into a double boiler. Fill a saucepan with 1 to 2 in (2.5 to 5 cm) of water. Set a heat-safe bowl on top; make sure that the bottom of the bowl does not touch the bottom of the pan. Pour the grated soap into the bowl.
- If you have a crock pot, use that instead if you like.
- It’s also possible to melt the soap directly in a saucepan without the bowl. Just use a smaller saucepan to ensure the soap doesn't scorch.
- Alternatively, melt the soap in the microwave in a glass bowl covered with plastic wrap, heating it for 1 minute at a time. Stir after each minute until the soap melts.^{[1]
  X
  Research source}
4
Pour water into the double boiler with the soap. You need 9 ounces (255 ml) of water per 12 ounces (341 g) of soap. Adding water helps thin the soap and soften it up.^{[2]
X
Research source} Avoid adding too much liquid, however, or the soap won't dry properly.
- If you want something extra-special, try tea or milk instead. Regular cow’s milk, goat's milk, or buttermilk are all good add-ins.
- If you use freshly-made cold process soap, you may not have to use as much liquid, if any. Start with 2 to 3 tablespoons (1 to 1.5 fl. oz.) and add more if necessary.^{[3]
  X
  Research source}
5
Heat the soap, stirring every 5 minutes or so. Turn the stove on to medium-high heat and allow the water to come to a rolling boil.^{[4]
X
Research source} Stir the soap every 5 minutes or so with a wooden spoon or rubber spatula. Make sure that you scrape the bottom and sides of the bowl to keep the soap at the bottom.
- If you're using a crockpot, cover it with a lid and set it to high heat. Crack the lid open and stir it occasionally – every 5 minutes or so – so the soap does not burn.
- If you heat the soap in a pot without the bowl, use low heat.
6
Continue cooking and stirring the soap until it softens. Rebatch soap will never fully melt like melt-and-pour soap. Instead, it will soften into a grainy mixture, sort of like oatmeal or mashed potatoes. Be patient, though! This can take about 1 to 2 hours.
- At some point, the soap will no longer change texture. If some time has passed, and the soap still looks the same, it won't melt any further.^{[5]
  X
  Research source} You are ready for the next step.
- If the soap starts to scorch or change to a brownish color, turn down the heat and add a little cold water.^{[6]
  X
  Research source}

Part 2

Part 2 of 3:

Adding Extras

Download Article

You do not have to add any of the extras from this section if you don't want to, but they make your soap feel more luxurious. You also don't have to add all of the extras. Choose one or two (or three!) that appeal the most to you!
2
Stir in some fragrance oil or essential oil for a nicer scent. Williams recommends, “You'll want to spend some time researching and then investing in some good quality fragrance oils or essential oils if you want an all-natural soap bar.” Plan on using about ½-ounce (15 ml) of oil per 12 ounces (341 g) of soap.^{[7]
X
Research source} If your soap is already scented, you might want to skip this step or use a fragrance oil with a similar scent. For example, if your soap base is lavender scented, you could add an extra drop of lavender oil.
- You don't need to use as much essential oil as Soap-making fragrance oil. This is because essential oil is much more potent.
- Do not use a candle-making fragrance oil. It is not skin-safe.
- Another option for fragrance is through spices. This will also give your soap some color. Plan on using 1 to 2 tbsp (7.5 to 15 g) of spices, such as ground cinnamon.
3
Mix in some nourishing oils for extra luxury and moisture. If you want your soap extra fancy, add a few drops of nourishing oils, such as vitamin E, jojoba, almond, etc. Anything that you'd put on your skin is great for soap. Williams says, “You want to include these nice soft oils that can add moisture to the soap and your skin when you put it on.” Don't get too carried away here, however; too much oil can affect the curing process!
- Another nourishing additive is honey. Not only will it make your soap smell nice and be more moisturizing, but it will also give it a nice, golden color. Plan on using ¼ to ½ cup (90 to 175 grams) of honey.
4
Add a few drops of soap-making dye for color. Because the soap-making dye is translucent, this option is only recommended for white-colored soaps. Purchase some soap-making dye online or from an arts and crafts store. Color your soap by adding 1 to 2 drops, then stir it in. Keep stirring until no streaks remain. If the color is not deep enough for you, stir in another drop.
- Soap making dye is very strong. Mix in 1 to 2 drops at a time until you get the color you want.
- You must use soap making dye. Do not substitute candle-making dye, as it is not skin-safe. Food coloring will not work, either.
- Add dye to brighten an existing color. For example, deepen a light blue soap base with blue dye.
5
Add some texture with botanicals and exfoliants. This is great for those with dull or dry skin. The exfoliants gently buff away dry skin, leaving your skin feeling silky-smooth. Great choices include sea salt, oatmeal, and dried lavender buds. Brow-Polanco says, “Some great herbs and oils that make beautiful soaps and are good for the skin are calendula flowers (not to be confused with marigolds), frankincense essential oil, geranium flowers, myrrh oil, Irish moss, comfrey, carrot seed, and chickweed.” Here are the recommended amounts for every 12 ounces (341 g) of soap:
- ¾ to 1 cup (90 to 120 g) of exfoliants, such as oatmeal, almond meal, coffee grounds, etc.
- 1 cup (50 g) of herbs with low volatile oil content, such as chamomile, calendula, and lavender. The herbs can be fresh or dried.
- 1 to 2 tablespoons (1 to 2 g) of high volatile oil content herbs, such as rosemary. They can be fresh or dried.
- Adding botanicals and then wrapping the finished soap is also a cute gift idea. “You can also wrap it in a nice cardboard box, something more natural…nothing with plastic because you don't want to mess with the wax or oils (in the soap),” Williams recommends.

Part 3

Part 3 of 3:

Pouring the Soap

Download Article

1
Prepare the mold to hold the melted soap. Purchase a plastic soap-making mold. If your mold is plain and you want fancy soap, add a rubber soap-making stamp into the bottom, design-side-up. If you want to, lightly spray the inside of the mold with non-stick cooking spray or rub a little bit of petroleum jelly into it to make it easier to get the soap out.^{[8]
X
Research source}
- Purchase soap making molds and stamps online and in arts and crafts stores.
- Alternatively, you could use a silicone ice cube tray or baking mold.
Because this soap is thick, you won't be able to pour it in. Instead, scoop the soap into the mold using a wooden spoon or rubber spatula. Smooth the back of the mold down with the spoon or spatula.
Hold the soap mold about 6 to 12 in (15 to 30 cm) above the counter, then drop it. This settles the soap in the mold and releases any air bubbles. You may need to do this a few times.
4
Let the soap to dry for 1 to 2 days before removing it from the mold. Once the soap is dry, carefully pull it out of its mold. If you used a long, rectangular, soap-making mold, cut the soap into 1-inch (2.54-centimeter) thick slices. Williams suggests using a crimp cutter or slicer that has ridged edges to make the soap look like it has been crimped for a more interesting shape.
- If you're in a hurry, pop the soap into a freezer for 1 to 2 hours before de-molding it.
5
Allow the soap to cure, if necessary, for up to a month. Depending on the type of soap you use, your rebatch may still feel a little soft and gummy. In this case, set it down on a wire cooling rack and let it air dry for 2 to 4 weeks. If you used store-bought soap, you might not need to do this, but if you used freshly-made cold or hot process soap, you most likely will.
- Some types of rebatch soap (typically made from store-bought bases) only need to dry for 2 days.

Community Q&A

Search

Add New Question

Question

Can I melt a Dove bar soap?

wikiHow Staff Editor
Staff Answer
This answer was written by one of our trained team of researchers who validated it for accuracy and comprehensiveness.

wikiHow Staff Editor

Staff Answer

It may be possible to use Dove hand soap for melting and reforming into a bar of soap but people report varying degrees of success because there is a lot of moisturizer in Dove soap, and this can impact the effectiveness of the rebatching process. Look for a rebatch recipe specifically focused on Dove soap, and that shows a successful outcome in the photos. If you find it’s just not working, Dove soap is reported to make an excellent liquid soap, although it can be a bit of a pricey way to produce it!

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 3 Helpful 30
Question

Can I melt soap in the microwave?

wikiHow Staff Editor
Staff Answer
This answer was written by one of our trained team of researchers who validated it for accuracy and comprehensiveness.

wikiHow Staff Editor

Staff Answer

You can melt soap in the microwave, just be sure to use microwave-safe dishes. Use glycerine soap pieces or bar (other soaps may explode in the microwave), and grate or chop the soap into very small pieces. Put the pieces into a microwave-safe dish and either add a lid or microwave-safe food wrap to prevent splatters. Then, microwave on high in spurts of 15 to 20 seconds. Remove and stir, then continue heating in bursts until the melting is done (reduce to 5 second bursts when close to melting). Handle the melted soap with care, as it will be very hot.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 10 Helpful 22
Question

Can you melt soap on the stove?

wikiHow Staff Editor
Staff Answer
This answer was written by one of our trained team of researchers who validated it for accuracy and comprehensiveness.

wikiHow Staff Editor

Staff Answer

Yes, melting soap on the stove is a standard way of rebatching soap. The article above explains the full process to follow.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
Yes No

Not Helpful 4 Helpful 22

See more answers

Ask a Question

200 characters left

Include your email address to get a message when this question is answered.

Submit

Video

Tips

Don't toss that last bit of bar soap. When you're ready to start a new bar of soap, make sure the old soap is wet and stick it to the new one. It will melt right in after the first wash.

Thanks
Helpful 2 Not Helpful 2
You can also just let the leftover pieces of soap sit in water for a while until they get soft and pliable. Then squeeze them together in your hands till they stick together. Let this new "bar" set a bit till it firms up and you have a new bar to use.

Thanks
Helpful 2 Not Helpful 3
Open a window or turn on a fan if you're working with scented soap or fragrance oils.

Thanks
Helpful 0 Not Helpful 3