CPOP: Cold Process Oven Process

temperature of the oven is in relation to the watercontent of the soap
when you have lyewater over about 28% (in relation to your total amount of fat/oil ) your oven can be warmer (around 160 F , 70 C) to force gelphase
I usually soap with a steep waterdiscount (everything from 16-25%) my soaps are not supposed to gel (that would need distiinctly more heat) my oven is around 122 F, 50 C for a few hours to get full saponification, and no sodaash

the point is, you can not generalize the temperature of the oven when CPOPing since it very much depends on the recipe

Replying to this old thread with a CPOP question if anyone can help? Can I used a wooden mold with silicone liner for CPOP? Glued not screwed...

Personally I wouldn't, but what you can do put a heating pad under soap cover it with a towel or have it in a cupboard. Keep an eye on it' once it reaches jell stage' turn heating pad off let it cool down tell the next day. Or just cover it if its in a cupboard or a location it stays warm. once the soap starts to heat up' it will usually continue to generate it's own heat source.

Katie68121 said:

Replying to this old thread with a CPOP question if anyone can help? Can I used a wooden mold with silicone liner for CPOP? Glued not screwed...

Click to expand...

First off, as long as your CPOP temperatures don't go high enough to melt the glue, yes, you can. I do and have never had an issue. I have not smelled melting glue or had my molds deteriorate. I usually CPOP at around 135-150°F, using a setting slightly below the lowest on my oven's temperature knob & an oven thermometer to verify the temp before putting the soap inside (and turning off the oven.)

I use my wooden molds with silicone liners, but I'd have to double check on if any don't have screws. I think they all do. However, I am pretty sure that at least some of the molds that do have permanent screws probably also have glue. By permanent, I mean the ones that aren't the 'come-apart' kinds of molds with the long bolts & wing-nuts, so the sides can be removed. And at least one of them is made of plywood or pressed wood, so it definitely has glue as that is used in the process of making plywood.

Burning plywood in a woodstove or in a fireplace is ill-advised because it releases toxins into the air, but I do not heat my oven for CPOP to such high temperatures. Wood glue starts to melt at 120°C which is 248°F, so that's not a problem for the temps I use for CPOP either. Urea formaldehyde glue, used in making plywood melts at 230°C which is 460°F, so again, no problem for CPOP.

Katie68121 said:

Replying to this old thread with a CPOP question if anyone can help? Can I used a wooden mold with silicone liner for CPOP? Glued not screwed...

Click to expand...

If you preheat your oven to 110*F and turn it off before you put your silicone lined timber mold which you wrap in a blanket or towels you can. That is the true CPOP method that is foolproof.

But if you are going to keep the oven on while your soap is in the oven or preheat your oven to over 110*F I would not do it.
There are lots and lots of threads on this forum where people have overheated their molds and they now have a silicone rash. it's an invisible rash that shows itself every time you use the mold again giving the soap pock like marks all over the sides that touch the mold.
I wouldn't risk it.
Silicone molds are expensive.

First off, I hope this thread is not too old for me to post. If it is I apologize. My oven is very warm just from the pilot flame. So I don't usually turn it on. I just put the soap in for about an hour and then take it out to cool. Should I leave it in for longer because I obviously can't "turn it off and let it sit overnight". Also, does anyone know if the CPOP would fade the scent of soaps made with essential oils? Thanks for all the helpful info on here!

Goldy said:

First off, I hope this thread is not too old for me to post. If it is I apologize. My oven is very warm just from the pilot flame. So I don't usually turn it on. I just put the soap in for about an hour and then take it out to cool. Should I leave it in for longer because I obviously can't "turn it off and let it sit overnight". Also, does anyone know if the CPOP would fade the scent of soaps made with essential oils? Thanks for all the helpful info on here!

Click to expand...

The idea is to get that soap into an environment that is hot enough long enough to force it to go through gel. And you only want to do that when you either get no gel (and want it to gel), or you get partial gel. This is a method for rescuing bars that would otherwise not be as pretty as you want them to be, so trying to preserve scent is a balance you are going to have to figure out.

I would not have put the mold above in my oven. I don't have a gas stove, so I have to go to 170F as that is the lowest my oven will go. It would have melted the wood glue. But you have to make decisions based on your current situation.

I personally put my molds on a heating pad to force gel as soon as I pour them. Layer old beach towels on top of the molds, and watch them closely for the next few hours. If you see gel reaching the sides, turn the heating pad off, pull the towels off, and let the soap cool.

So are you saying that the oven should only be used as a rescue method?

Basia said:

So your loaf sits in the oven for about 6 hr. while the oven is on? Is your loaf covered up or not?

Click to expand...

I was told gel takes place with 2 hrs so I set my time for 2 hrs then take it out. I've never had a problem with any soap even if it contains sugary ingredients. The heat helps to equalize the temperature of the soap throughout without which the soap can crack/overheat/volcano.

@Goldy - no it's not just a rescue method. I do it for every soap I make.

I agree, it's not just a rescue method for me either, although I have used it to rescue partially-gelled soap. But I do prefer the heating pad method since I don't want the FO or EO scent to transfer to my oven - which it does, although I don't find it makes the scent of the soap fade any faster.

CPOP is not just a rescue method. It is a method of ensuring gel.
You need to heat your oven to about 120*F (50*(Yes this is very low) and then turn it off. Wrap your soap in towels, put it in the oven and leave it, undisturbed for 12 hours. Do not open the door.

If you have an oven with a pilot light (exposed gas flame) and it will not turn off this method is not for you.
You can use a polystyrene box to do the same thing. Wrap your soap and put it in the polystyrene box and leave for 12 hours undisturbed. If it is winter I put a doona over the top of the box. In fact I do that summer and winter.
The idea is to provide a little cocoon where the soap does the work of heating itself but your little cocoon provides a little warm environment for it for 12 hours.

Thank you