Soap Making Processes
Melt and Pour lye soap. There is no such thing as a soap made without lye but not everyone wants to work with lye beacause it is highly caustic and care should be taken with storage and handling. If you are one of these people there is a solution,,, you can start with a soap base where the lye has already been combined with the fats. This method is called "the melt and pour" method. The obvious advantage to this is the fact that you do not have to store or handle the lye and, if you do not wish to choose your own combinations of oils/ingredients for the base soap, it is a less complex way to go. It is exactly as it says - you melt it, add the colors, scents, and anything else and then pour into molds to set.
Cold process lye soap. This method does not require and external heat source to force the saponification to begin. The lye mixed with the appropriate amounts of fats/oils starts it's own saponification process. Different amounts of lye are needed for different oils so make sure you refer to a lye calculator when you use this method for soap making. Also, be sure to follow proper storage and handling procedures. From start to finish this process takes a few weeks.
Hot process lye soap. The lye mixed with the appropriate amounts of fats/oils are boiled. This is the way it was done in the past and can still be done this way. Soap made this way can be used the next day but it does take alot more personal time in the making. The saponification process is completed in the pot and all excess water is boiled off. This takes a few hours and it is not something you can walk away from for very long, if at all. Once again, using a lye calculator is a good idea. Also, be sure to follow proper storage and handling procedures.
Rebatching. This is purely melting down old soap shavings and remolding. This even applies to commercially purchased soap.