As we talked about in the other thread - check it regularly to see when it is firm enough and soft enough to be taken out and cut. Once you know the approximate time for your situation (recipe, cook time, mould size - so many variables play in to the time when a soap is ready for cutting) then you can work to that more. If you know last time you made this soap it was ready in 12 hours, you could most likely leave it that long again