Extra time in the oven?

wearytraveler · Jul 25, 2016

I was reading another thread that made me think about this and wanted to ask if it's something worth trying.
After letting a batch set for it's normal time and cutting into bars then waiting another couple of days, would there be any benefit to placing the bars into the oven for a short time with some low heat to help with curing? I was thinking about standing the bars on a silicone cookie sheet and placing them in the oven for 12 hours (more or less) while keeping some heat going (on and off to keep the temp at about 100). I'd be present for this, of course. Any thoughts?

dixiedragon · Jul 25, 2016

I haven't done cut bars, but recently I've found it makes unmolding soaps easier. If my soap isn't easy to unmold after 12 or 24 hours (depending if I'm soaping overnight or on the weekend), then I preheat my oven to 150 or less and pop the soap back in and turn off the oven. So far I've been very pleased. I don't see any harm in doing it with cut bars.

IrishLass · Jul 25, 2016

I personally don't see any benefit to it other than increasing the evaporation rate, but one needs to keep in mind that there's much more that happens during cure than evaporation.....things that only time (not temperature) can achieve. You can certainly try it by all means, but for me it would be a huge waste of time and energy with very little (if any) gain.

IrishLass

newbie · Jul 26, 2016

I have put fully saponified bars into the oven to heat but only within a day or so of making them. It can help even out the look of partial gel and it can help colors pop a bit but I don't know that it would benefit soap that is 3-4 days old and nothing speeds cure.

As an experimenter, it never hurts to try something. You can take some good close ups of the bars before and after the heat of the oven and see if there is any notable difference in color or texture. If it's just to try to speed cure though, I wouldn't bother with it. The only cure for cure is time.

edstewbob · Jul 30, 2016

To speed up saponification right after pouring into the molds I typically put my soap into the oven at low temperature as a step in the CPOP (cold process oven process). I know this is not what you were asking but I wanted to mention it in case some people are not familiar with this method of reducing saponification duration.

topofmurrayhill · Jul 30, 2016

wearytraveler said:
I was reading another thread that made me think about this and wanted to ask if it's something worth trying.
After letting a batch set for it's normal time and cutting into bars then waiting another couple of days, would there be any benefit to placing the bars into the oven for a short time with some low heat to help with curing? I was thinking about standing the bars on a silicone cookie sheet and placing them in the oven for 12 hours (more or less) while keeping some heat going (on and off to keep the temp at about 100). I'd be present for this, of course. Any thoughts?

I think this could speed up some of the short-term things that happen after soap is made. Water evaporates at a rapid rate at first and this would contribute. If soap was a little cool during the initial saponification, this might help finish it off. However, it wouldn't speed up any of the longer-term things that happen during the curing of the soap.

You can also save a week or two of drying time and ensure better saponification by increasing your lye concentration (using less water) and making sure the soap goes through gel, or at least reaches those temps.

Keep in mind that heat accelerates oxidation and ages soap. To fix something that didn't go right, such as if you got partial gel and don't like it, this could be a reasonable way to correct it. Otherwise I would focus more on the initial soapmaking process.