Sometimes when making soap something does not go quite as planned - not all the lye was diluted when the lye mixture was added, during gelling the soap overheated, the soap was mixed too long and seized, forgot to add an essential ingredient. But soap does not need to be thrown away, not even funky soap, as long as the basic recipe measurements (balance of lye to oil/fats) stay correct.
If you have a batch of soap that went really wrong and parts separated, make sure to save EVERYTHING including the yucky gobby stuff as it is all part of the original recipe.
Below is how I rebatch soap:
Noodle the soap (preferable not that old, like in a week or two after the initial batch) with an electric kitchen grater (like zucchini) and add noodles to a large non aluminum pan. Lightly pour milk (any milk) over top of noodles (I use about 1/2 to 1 cup; more for older, drier soap) but not so much it pools on bottom of pan.
Have the inner pan with noodles nestled into an outer pan with boiling water, the technique is called au bain marie. This way the soap can not scorch as the bottom of the inner pan never gets hotter than the temperature of boiling water. I use a lid to help with heat retention.
After a bit, half an hour to an hour, the noodles start melting. With a large spoon or ladle scoop from the bottom to the top, to stir the mostly melted with the hardly melted at all.
Keep an eye on it and stir every once in a while, like very half hour or hour or so. Also keep an eye on the outer pan water level and refill if needed. Make sure to evenly stir unmelted parts together, also the bits stuck to the sides, so it's mostly at the same melting stage when ready to pour.
When the batch is done, the melted soap kinda looks like lava, a bit thicker at the top and edges and pretty liquid in the hot middle.
Mix everything up one last time especially the edges and pour quickly into a block mold. I don't have much luck pouring rebatched soap in shape molds without
bubbles so I stick to block molds and cut down to size later.
At first the poured soap will be quite dark, but over time it will lighten up. Rebatched soap will not have the same color as the original tho it will be close. This soap was more a pastel yellow but rebatched became bright yellow. Rebatched soap also tends to have a pearlessence to it, the folds and whirls of the thicker poured soap stay slightly visible in the body of the soap and looks very nice cut. I also found rebatched soap does not cure as hard as the original (or it just takes much longer) but don't know if that shortens it's shelf life or not. Certain soaps I prefer rebatched over straight, especially because of the pearlessence look, but probably also cause they really like to overheat :)
Why does soap sometimes overheat, in case you're wondering?
A biggie is forgetting it's still plugged in and wrapped up. I gel my block soap on a seed starter mat covered with a piece of insulation foam and wrapped in a moving blanket. I leave the seedstarter on for 15 minutes to an hour depending on ambient temperature (basically, is it summer or winter), unplug it and leave the mold wrapped for another hour or more, until it's mostly gelled (check out an earlier blog post). And sometimes I forget to check in time... darn the kid :)
Another one is a large amount of soap made with milk and added honey. Milk soap runs hotter than regular soap (no seedmat needed, wrapping enough). Add honey and you don't even want to cover it (which is why making milk & honey soap poured into bubblewrap such a skill, hihi). And if you make a batch of milk soap with honey (like my Bee Good) and pour the whole recipe into one block mold the mass of the soap generates so much heat it needs to be cooled down - I place it, uncovered, on my concrete basement floor. And yes, it's easier to make this soap in winter!
