Introduction: Recycle Your Old Soap

Picture of Recycle Your Old Soap

Have small insignificant pieces of soap in your bathrooms, kitchens, or workplaces? Follow this instructable and you can recycle your soap!

Step 1: Choppy Choppy!

Picture of Choppy Choppy!

What you'll need:

1. The ugly soap.
2. A styrofoam cup, or other microwave safe container you'd like.
3. A microwave.
4. Knife or the likes.
5. Disposable cutting surface, Paperplate!

Collect all of your little pieces of soap. These are usually the ones that have become small, balled up, dirty, or disfugured from too much use. Don't get me wrong, hand washing is a good thing. :)

Gather all of the mutant soaps and put them on a paperplate. Get your knife (I just used a butterknife) and cut all of the soap into tiny pieces. The smaller the better usually.

Step 2: Soap Formation.

Picture of Soap Formation.

After chopping up all those little soaps, mix up the newly formed pieces and place in a styrofoam cup. Push the soap pieces into the cup so that they are snug, and then fill the cup with water so it comes to the same level as the top of the soap.

Step 3: Microwave It.

Picture of Microwave It.

Get your cup o' soap and put it in the microwave on something to collect anything that may fly out during the soap transformation (like a napkin).

Put your microwave on for maybe 30 seconds.


After you've microwaved the soap until some of the water rises out of the cup, remove it from the microwave and set it somewhere. You can use this time to find something that has the same diameter as the middle of the cup, and a sandwhich bag or ziploc bag. Put the object in the bag, (I used a vitamin bottle) and push it into the soap to make it more dense.

Step 4: Finishing.

Picture of Finishing.

Now, leave the water in the cup at the same level as the soap, and place the cup somewhere to sit for about a week. A good place to put it is somewhere around your sink, so incase it spills, it spills into the sink. After about a week, the water in the cup should evaporate, leaving you with a new bar of soap.

I hope you enjoyed this instructable!

This is an Idea I had that could maybe get small kids to wash their hands more. When you're in the begining stages of putting the soap pieces in the cup, maybe put a couple of quarters in the middle of it, when it solidifies there will be money in the middle, a reward for throughly washing hands. Little kids always love shiny money. :)


hInstance made it! (author)2017-05-27

I made two of these but I put the soap bits in a blender to really cut them up ( and yes I thoroughly washed out the blender when finished ). Havent tried them yet.

Katwi (author)2016-12-01


I was looking for such a method because I'm in a waste-reducing process. Why would you want to recycle your soap otherwise ?
But lots of disposable stuff are being used here. Do it smart, use washable ustensils !

FlorinJ (author)2016-08-21

Soap (supposedly) melts at a quite low temperature - well below the boiling point of water. Significantly overheating it may easily cause it to change its chemical structure. It's probably safer to melt it in a double boiler - with no water at all, whatever water you add you'll need to evaporate later on, or else your soap will be extremely soft. You don't even need to have the water boiling, it's enough to just keep it very hot, at about 55-60 degrees Celsius/120 - 125 Fahrenheit.

You can use a plastic cup (one left over from yogurt, or the cut out bottom of a plastic bottle, for example) placed in a pan filled with water, and boil the water. This should be safer (for the soap) than microwaving. Plus, plastic bottles and yogurt cups are smooth, unlike styrofoam cups, leaving the re-melted soap bar with a smoother surface.

Last time I did this, the plastic cup idea did not yet occur to me, so I just placed all soap pieces in a plastic bag and tied it up with as little air inside as possible, then boiled it in water for about 15 minutes, then left it to cool in a tiny bowl and peeled off the bag. The recycled soap bar came out nice and smooth, although a little oddly shaped. Only, a plastic bag is too easy to puncture and difficult to close up so that no water gets in while air still can get out.

MarissaR1 (author)2015-04-19

I did this and it is goopy. Whats wrong?

FlorinJ (author)MarissaR12016-08-21

I can't be sure, but you possibly overheated it and changed the soap's chemical structure.

TracyW34 made it! (author)2015-12-14

(First attempt at soap recycling) I was cleaning and purging last night and came across about 6 bars of used recyclable soap .. So to the kitchen I went were I got myself a small pot and placed it on the stove ... I broke my soap in to small pieces then added about 1/4 c of water and placed my heat on med for about 20 min .. Stirring and breaking the soap down further with a knife .. I didn't quite like the scent of the soap so I added in about 2 tablespoons of almond extract, and the soap that I was breaking down seemed to dry the skin out so I added in a handful of oat meal .. Added in about another 1/4 of water and let that cook for another 15 min on a reduced heat .. Once the oats were cooked I then took my hand pulse blender ( I'm sure a food processor for regular blender Could work too just transfer the soap when it's nice and hot) and I pulse blended out the larger lumps of soap and blended the oatmeal so it was no longer in large flakes and my soap was creamy.. I then lined a loaf pan in its entirety with parchment paper then poured the soap into the pan .... To insure I had no air bubbles in the pan I took the handle edges lifted it up then just dropped it gently on to the counter about 4 or 5 times .. I folded the edged of the parchment paper over then patted it down to make it smooth then set it outside in the bbq ( it's winter time now so it's pretty cold out there otherwise I'd suggest the fridge ) after leaving my soap for about 3 hours I then brought it inside and sliced it in to 1 inch thick slices and put it back outside for the night .. This morning it was raining so there's lots of humidity so I retrieved my soap from the bbq And brought it in the house were I have now pulled it out of my pan and pulled the peices apart so they are seporated and now drying on the counter .. It was super easy to do and recommended if your trying be frugal with your pennies

LMEYTCHISON (author)TracyW342016-01-31

Tracy, thanks for the information you gave I will try it later.

RuthB17 (author)2015-11-16

love this

Lajuj (author)2015-03-14

Hello sir/madam.

Thanks for the good idea on recycling soap.

i tried to recycle my bar soap which was made by palm oil only and it was good soap but the problem the bar soap gets broken , i made about 100 bars of soap they all got broke in halves.

Can you help me may be imissed something when I was mixing.

MichelleF35 (author)Lajuj2015-09-27

You may need to adjust your recipe and dry it longer before you use it.

IsabelB5 (author)2015-08-28

another way you could do this to make it a little nicer looking is boiling water, putting the soap pieces in a heat resistant bowl smaller than the pot and put it in the water so that the bowl is floating. Add about two teaspoons of the boiling water into the bowl. Then wait until the pieces are pretty mushy. Take out the bowl and carefully mush the soap pieces together. Then scoop out the soap and mold it into whatever shape you want (on a piece of tin foil). Lastly put it into the refridgerator until its hard.

AndrewP27 (author)2015-08-04

I can`t believe how easy this was, I have arthritis in my hands and once a bar of soap is worn down below half I really struggle to hold it and was wasting so much, so after I got my niece to chop up the old bits we got to work and made over ten bars which would have cost me about £8, i,m over the moon

MarissaR1 (author)2015-04-19

Never mind I figured it out.

clare.vickers.3 (author)2014-11-12

Great! I had 2 soaps that had lost their scent, so I did this, added cochineal for colour and essential Lemon Thyme and Lavender oils, and have very nice soap evaporating on the kitchen window sill.

BellaF1 (author)2014-10-27

I did this to reuse some goats milk soap scraps, but it didn't work. I think it might be because it wasn't a commercial soap. It was made with several types of organic oils like coconut, anise, etc. But I just took the soapy water and put it in a foaming hand soap dispenser and it works well for that. Like a nice concentrated moisturising soap.

AngietimC made it! (author)2014-10-19

my husband makes soaps and stuff

yeslordnow (author)2014-07-13

I think this is an awesome ideal as a Science project to make in Childcare,, ages 4-5 being supervised. awesome

tonygoffe (author)2013-03-08

...NOW...if someone could just do an Instructable on "How to make a Soap Mold/Press" ..we'd be in Heaven !!!!!!!

danB_TO (author)2013-02-09

I have tonnes of these little scraps in the corners of the shower. Brilliant! I did what you've suggested here, but to make the bits smaller, I added the chunks to my old blender with about an equal volume of water and blended/pulsed for less than a minute. I then heated the resultant creamy paste in a double pot system (soap pot inside larger pot with boiling water). Then scooped the gunk into a 1liter cut-off milk carton. We shall see.

Sparsely (author)2013-01-19

I like this instructable. But if you're doing the add quarters thing, bear in mind that coins are absolutely filthy (unless, I guess, it's brand spanking new out of a roll). Putting something filthy in the middle of my bar of soap grosses me out.

sismart (author)2012-05-14

As for the money issue in the microwave, don't add it till AFTER it's cooked. I just did this (no money) and the soap bubbles up and is very soft. You have to push it down with a spoon to shape it. At THAT point, add whatever you'd want to the pending bar ...

rfeickert (author)2011-12-11

With regard to quarters causing sparks, this would not be a problem as quarters dont have jagged edges to spark from. See the Mythbusters episode regarding metal in microwaves.

Dark_Merlin (author)2010-04-26

Just a comment on the money in the soap, this is a reaaaallllyyy bad idea if youre gunna be using a microwave. I predict sparking, exploding, boiling microwave soap flying everywhere if you attempt this.

peacenique (author)2010-02-18

Thanks, I love the idea and easy peasey instructions!

Darcy777 (author)2009-08-13

I like your detailed instructions and that you added suggests, as to what you did - like the vitamin bottle. Thanks for the Instructable!

ladygold (author)2009-07-30

I used a food processor to chop up the soap pieces; they packed more closely that way. The whol process worked perfectly. Thanks!!

Derin (author)2009-07-17

Weird.The thumbnail of the result looks like ice cream!

Julibopper (author)2009-03-07

I seem to recall soap with toys in it from when I was little. Plastic in the microwave isn't quite so explosive. And bright toys are just as good as shiny money :)

dchall8 (author)2009-01-17

I tried something a little different. I put the crude soap into a little dish that "instant" macaroni comes in to heat it. Without chopping it up or adding any water I nuked it for 15 seconds. At that point I took it out and it was very soft. I pushed the soft soap down with the back of a spoon. As soon as it cooled it was ready to use.

JellyWoo (author)2008-06-23

i microvaved it for a full minute and nothing rose out of the cup!

JellyWoo (author)JellyWoo2008-06-23

finally, after 1 1/2 minutes stuff finally comes out!

farfugliare (author)2008-02-10

Great instructable. I'd be careful about adding the quarters to the soap and then microwaving it, though.

Transquesta (author)2008-02-10

I just put my scrap soap in an old sock. When the foot portion of the sock is full, I tie it off, boil it for a couple of minutes, take it out to cool, squeeze out all the extra juices, and hang it on my shower rod to dry. In about a week, I untie the sock and have a monster "soap egg." (Note: the sock, too, is recyclable. :-))

rerat (author)2008-02-09

Couldn't a double boiler complete this process without the waiting period?

Gunk on Floor (author)rerat2008-02-09

I guess so, that'd be a good thing to look into. -

About This Instructable




Bio: I enjoy visiting the dump to look at, and take, all the free stuff people throw away. It's a lot of fun. I like ... More »
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