So, what do you do with the soap scraps? You can:
1) Throw them away- neither ecologically sound nor good for the budget
2) Put them by the hand basin and hope people will feel they have to use them up – unlikely, they’ll probably just sit there and dry up and look yuk while everyone avoids them
3) Save them in a container until you have a cupful, then boil them up with water in an old saucepan, mush them into goop and use it to wash your clothes – practical, but messy and not much fun
4) Put them in an old-fashioned “soap saver” (a little wire basket with a handle; you put soap inside, close it up, and agitate it under a running hot tap) to wash your dishes- but it leaves soap scum on your dishes, and where would you find a soap saver these days?
5) Put them in the cut-off leg of a stocking/pantyhose and tie to your outdoor tap for washing hands after gardening- this works with bigger bits, but scraps dry out/break up/ don’t lather
6) Leave them in the soap rack where they will fall out, or in the soap dish to go mushy/mouldy, and pretend it’s someone else’s problem- yuk (it become’s everyone’s problem)
7) Leave them in the bottom of the shower to stick on like limpets while they slowly get melted away/go mouldy/cause someone to slip and bang their head/break the shower screen etc – don’t say I didn’t warn you
8) Leave one on the kitchen sink for the mice to take - I kid you not, this happened (one day there were little teeth marks in the soap; the next morning it was gone!)
or – ta-dah!
9) Mold the scraps onto a new bar of soap, and experience the constant joy of a decent-sized piece of soap to use, whilst basking in the self-righteous glow of someone who isn’t making any mess or wasting a thing! If this is your preferred option, read on…
Step 1: Soften Old and New Soap
Soap which has an indentation in the side works best, but a more rounded cake of soap works fine, too- just make sure it’s softened enough to work with as in the next step.
* It's easier if the new soap has been used a few times to wear down the edges and soften a bit- see the second example (white/white). I's also easier if you use your scrap before it dries out too much and hardens.
Note- I've shown a white scrap on green soap so it's clearer, but it looks much better with the same colour- e.g. white on white!
Step 2: Score Some Lines for a "key"
If the new bar has an indentation, make sure your scoring goes up the sides of the indentation.
Step 3: Press Together
Step 4: Score Around the Edges
Step 5: Smooth Over
Step 6: Use It!
You probably won't want to put out the conglomerate soap on your hand basin when you have guests you want to impress, but it will be fine for family use in the shower.
Bonus - use the sponge or cloth that you soaked the soap on to wipe down your bathroom mirror; the soap on the sponge will make the mirror slippery, and it won’t fog up when you have a shower!