Speed up drying/curing time of CP soap?

Most people call it CPOP nowadays -- ITMHP is going to get you a lot of blank looks.

I'd also say most people here don't do the "170 degrees F for an hour" method anymore.

That much heat for that long often causes problems. Instead, preheat the oven to 120 to 140 F (some folks shoot for 110 F), turn the oven off, and then put your soap in the oven. Leave it in the oven for at least several hours. All you need is sufficient gentle warmth to encourage the soap to reach gel temperature.

CPOP isn't about "aging" the soap, and it's not the only way to accomplish the goal of gently warming the soap. You can often get similar results by using a heating pad, putting the soap in an insulated cooler, etc.

Avoid CPOP if you have a recipe you know will warm up well on its own -- recipes with added sugars or beer, or recipes with a lot of coconut oil are examples.

Yes, you can do CPOP in a cardboard mold although tape or glues may fail, especially if you decide to use the 170 deg F method.

DeeAnna said:

CPOP isn't about "aging" the soap, and it's not the only way to accomplish the goal of gently warming the soap. You can often get similar results by using a heating pad, putting the soap in an insulated cooler, etc.

Avoid CPOP if you have a recipe you know will warm up well on its own .

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What would be the motivator of doing cpop? Just simply to encourage gel stage and nothing more? My understanding would be that it would speed up saponification. The soap will still need plenty of drying time of course, but the sap time needed is shorter. I've never done cpop (haven't felt the need to) but am I mistaken here?

Thanks folks for the replies!

OK, CPOP it is. Sorry for any confusion. I thought CPOP was actually cooked in the oven with higher temps, as in a pot, not just kept warm in the mold. Back when I started making soap, people weren't cooking it in a slow cooker but now I see that a slow cooker is getting to be standard for cooking soap. No more boiling it in a pot in the oven or on the stove.

I think the tape will hold up to 120 or so. My recipe has sugar added and is made with some goats milk. Does that mean it will get hot on it's own as it ages in the mold, so just wrapping in bubble wrap will be enough? No oven needed? I have bubble wrap galore and usually wrap the mold in it.

I mix the scent in the soap outside and am concerned that, being winter, this will cool it down too much before pouring it into the mold to finish. Although, I will say that I have done it this way for years and not had many failures, so I guess that's not really a problem. I'd rather not put it in the oven for a long time, as hubby may need it for baking.

Yes, CPOP is to speed the aging. I don't want to cook it as I like the fluidity and smoothness of CP soap poured into the mold.

jcandleattic said:

Being "rock hard" is not an indicator of safety. Once a bar is fully saponified and there is no free lye in the bar, that's when it's safe to use.
Most CP if made correctly, is fully saponified and safe to use within 18-72 hours. However, fully cured and mild with no harshness, comes with time, and nothing that I have found has sped that up.
Hot process bars take just as long to cure as CP soaps do because curing is more than water loss.
IF curing was nothing more than water loss, then yeah, soap curing could be sped up. But that's not all there is to it.


I absolutely can tell a bar that is 2 weeks old from a bar that is 6-8 weeks old.

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I totally agree with you about the water thing. But if I wait any longer then 9 hours to cut I will break my string and I have to use fishing line. After 24 hours they are as hard as their going to get. They just lose weight from there. I really like to wait 4 weeks to sell but they stop losing weight at 2 weeks and from there they just age. If I used a bar after I made it the next day it would still last about 3-4 weeks in the shower. I've already tried it.
By the way, CP loses the same weight equally at the same rate as HP. I've already proved that to my wife. She no longer does HP to waste energy except if she wants too.

SherylG said:

I think the tape will hold up to 120 or so. My recipe has sugar added and is made with some goats milk. Does that mean it will get hot on it's own as it ages in the mold, so just wrapping in bubble wrap will be enough? No oven needed? I have bubble wrap galore and usually wrap the mold in it.

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I put my mold on top of a heating pad. I leave the heating pad on usually a little over an hour for my "sugars added" recipes when the temperature in the apartment is in the low 60s (my husband is from Alaska). My "no sugars added" recipe requires heat for approximately 4 hours to get full gel under the same conditions. I cover the molds with a cardboard box, then two heavy beach towels.

SherylG said:

I mix the scent in the soap outside and am concerned that, being winter, this will cool it down too much before pouring it into the mold to finish. Although, I will say that I have done it this way for years and not had many failures, so I guess that's not really a problem. I'd rather not put it in the oven for a long time, as hubby may need it for baking.

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Use the heating pad method. It keeps it out of the oven.

SherylG said:

Yes, CPOP is to speed the aging. I don't want to cook it as I like the fluidity and smoothness of CP soap poured into the mold.

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CPOP will not speed anything but gel, which gets the soap harder faster. And there is far more than loss of moisture going on during cure. Which can't be hurried no matter what you do.

Thanks Susie!

SherylG said:

Thanks folks for the replies!

OK, CPOP it is. Sorry for any confusion. I thought CPOP was actually cooked in the oven with higher temps, as in a pot, not just kept warm in the mold. Back when I started making soap, people weren't cooking it in a slow cooker but now I see that a slow cooker is getting to be standard for cooking soap. No more boiling it in a pot in the oven or on the stove.

I think the tape will hold up to 120 or so. My recipe has sugar added and is made with some goats milk. Does that mean it will get hot on it's own as it ages in the mold, so just wrapping in bubble wrap will be enough? No oven needed? I have bubble wrap galore and usually wrap the mold in it.

I mix the scent in the soap outside and am concerned that, being winter, this will cool it down too much before pouring it into the mold to finish. Although, I will say that I have done it this way for years and not had many failures, so I guess that's not really a problem. I'd rather not put it in the oven for a long time, as hubby may need it for baking.

Yes, CPOP is to speed the aging. I don't want to cook it as I like the fluidity and smoothness of CP soap poured into the mold.

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If your doing goats milk and sugar together please do not let it go in the gel phase.

iwannasoap said:

If your doing goats milk and sugar together please do not let it go in the gel phase. It will spoil your milk and or your sugar will explode. .

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I don't use sugar in mine but I can definitely say using milk in soap that gels doesn't spoil the milk. All of my batches use goat milk and most of them heat and gel on their own and I've never had a spoiled batch from it. But maybe u r referring to sugar added as well?

Thank you for the correction

DeeAnna said:

"...500ppt or a 476ppt in the water:lye ratio. That is found by (lye/(Lye +water))*1000..."

Actually that's NaOH concentration, not water:lye ratio. Your water:lye ratio is 1 at 500 ppt (parts per thousand) and 1.1 at 476 ppt.

Be careful with "ppt" because the chemistry types lurking around here may read this as "parts per trillion" and most non-chemistry types won't have a clue. I suspect you may have read Kevin Dunn's book Scientific Soapmaking. His use of ppt to mean parts per thousand is fine, but this definition of ppt isn't universal in general chemistry.

Most of us here use percentages instead, so to translate, you're using 47.6% to 50% NaOH concentration.

Yes, your rate of water loss will stabilize more quickly by using NaOH at these higher concentrations. But stabilization of water loss doesn't mean the soap is fully cured and at its best within 2 weeks.

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To me, it is the same thing but I am not saying that I am right. Change the ppt and it changes the ratio. It is just easier for me to control exactly how much water I am putting in. And again, thx for the correction. I'll remember that.

Thanks for the replies and info Suzie and everyone! Now I won't worry about cooking it or wrapping the mold at all anymore. I had never heard of cooking it in the mold in the oven. So much easier than cooking it on the stovetop!

I used to make soap, CP and HP regularly for a couple of decades, always with milk of some kind and also with sugar added. The milk has never spoiled or spoiled the soap. I have, of course, had failures for various reasons here and there (Oops!) just not due to milk spoilage. However, I never used to wrap the box mold until recently, just the last two batches and I partially cooked them for another reason... long story.

Anyway, thank you for that info!

I stopped making it for about 5 years but started again last winter with just a couple of batches. I'm trying to remember what I did years before and it's taken some trial and error to get it back.

When I made it regularly years ago I tried everything. You mention it and I've done it. Cooked every way, Cold process (but not mold in the oven. that was new to me.) The last few years I settled on just mix, blend and pour. I didn't even wait for trace. It usually reached trace in the mold and was not a problem getting every batch to saponify. The trick was starting warm enough. Took some trial and error to figure that out! I mix at about 115-117f. I think it traces as it cools in the mold after blending.

Anyway, that's my "go-to" method. I'm now trying to remember the details of my old process. The last batch I had to remelt as I forgot that the sugar and salt have to be added to the very hot lye water which is then stirred until everything is well blended. In the recent soap make, I added it to the cool mix and it didn't dissolve. Just sunk to the bottom after blending. So I had to melt it down hot enough to dissolve the sugar and salt with much stirring and heat. That cooked the soap, which turned out well anyway. I have learned to fix just about anything, if it's not burned and I know how I messed up the recipe.

So I'm going to keep it simple, just mix, blend, scent and pour.

Thanks again for the reassurance that a cool mix is all I need.

iwannasoap said:

If your doing goats milk and sugar together please do not let it go in the gel phase. It will spoil your milk and or your sugar will explode. Keep your lye water cold and your oils on ice in a bowl and then directly into the freezer.
And, most importantly - dont use bubble wrap unless your using on the bottom for an effect. It has to breathe.

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Have you ever made soap using goat's milk and sugar together? I have, and I assure you that it neither spoiled nor exploded.

If your emulsion holds well, there really isn't a need to get the soap to trace before pouring it, but if you think you have a problematic FO or have had ricing or separation in the past with a simllar recipe, I'd get it thicker first. If you are doing swirls or other "decorative" effects, you may need thicker batter for it to behave the way you want, too -- soap only at emulsion won't "drag" much.

I've often wondered if I could short-cut HP by adding superfat and FO's, etc just before the "applesauce" stage and putting the soap in the mold, it's pretty fluid at that point and will finish saponifying in just a few minutes if it's plenty hot. Something to try when I have nothing else to do, as I have more than enough soap for a few years already.

CPOP is great for getting full gel, and will save some on FO's too -- the faster the saponification, the less degradation of the aroma chemical from the lye. Also prevents partial gel, which some people don't like.

The only drawback is the potential for overheating from a "heating" FO or sugar plus milk (more sugar, actually) or beer, also too much sugar.

So far I've only made CP soaps with considerable amounts of hard oils, and with CPOP they are ready to cut as soon as they are cool, definitely by the next morning if I make them at night. No zap once they have gelled.

I use half hard fats and the CP soap is ready to cut the next morning, which is about 24 hours. I have to watch HP soap to catch it before it gets too hard to cut. I rarely make HP soap anymore. The end product is just not as nice. I have considered just partially cooking it, as you mentioned, but have not gone there. The less time and trouble it takes to make, the more I like making it. It's enough trouble just fixing the odd batch that doesn't go well. Hopefully there will be less of those as I get back into regular soap making.f

I always use sugar and goats milk together. That's probably one reason I can just mix and pour, it heats up in the mold.
You are right about the swirling - too thin to swirl. I may leave the next batch in the pot until it starts to thicken before colouring and pouring so I can swirl it...maybe. I don't want it to get too hard to pour smoothly in the mold. I'll have to catch it just as it starts to thicken, I think. Maybe a swirl is not that important. Just a mix of colours is good enough for me. Some are just one solid colour and some are not coloured at all. My next batch will be oatmeal and honey but I'm only adding the honey to part of it and using that to swirl in, since it will be dark brown in colour. I'm scenting it with banana so it will be oatmeal, honey and banana!

I'm enjoying making soap again! I had forgotten how much fun it is! Maybe you can give some away at Christmas?

SherylG said:

The last batch I had to remelt as I forgot that the sugar and salt have to be added to the very hot lye water which is then stirred until everything is well blended. In the recent soap make, I added it to the cool mix and it didn't dissolve. Just sunk to the bottom after blending. So I had to melt it down hot enough to dissolve the sugar and salt with much stirring and heat. That cooked the soap, which turned out well anyway. I have learned to fix just about anything, if it's not burned and I know how I messed up the recipe.

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Actually, if you dissolve the sugar and salt in the water before you add the lye, you won't have that problem. I don't use salt, but I remove a small amount of the total water, warm it slightly and dissolve the sugar, return it to the total water and add the lye. Works perfectly. But, you know, whatever works for you...

Sugar is energy. It creates heat. If it gets too hot you will get a volcano.
This is an example.
[ame]https://www.youtube.com/watch?v=Z0R_gqDwbJY[/ame]

Thank you for the idea Dibbles
I try to do whatever is easiest. I think it will be easier for me to just add it to the already very hot lye water and stir them all to dissolve at the same time rather than using energy and time to heat a little water just for the sugar. It's what I usually do and it works for me. I just have to remember to do that.

iwannasoap said:

If lye based soap doesn't breath then your milk will turn rancid and/or you will get DOS.

Sugar is energy. It creates heat. If it gets too hot you will get a volcano.
This is an example.
https://www.youtube.com/watch?v=Z0R_gqDwbJY

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I think a major issue is that you state things as absolutes with no caveats. "if you use milk and sugar it will do X y and z" and then come back and say "too much sugar" and so on. The first statement, that milk and sugar would result in spoiling the milk, was not accurate. It CAN or COULD, but that's not what you said.

The Efficacious Gentleman said:

I think a major issue is that you state things as absolutes with no caveats. "if you use milk and sugar it will do X y and z" and then come back and say "too much sugar" and so on. The first statement, that milk and sugar would result in spoiling the milk, was not accurate. It CAN or COULD, but that's not what you said.

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Indeed, ANY soap can spoil or get DOS, but so few actually do. And wrapping the soap a short time before cutting is not the problem that wrapping for the entirety of cure could be.

SherylG said:

Thank you for the idea Dibbles
I try to do whatever is easiest. I think it will be easier for me to just add it to the already very hot lye water and stir them all to dissolve at the same time rather than using energy and time to heat a little water just for the sugar. It's what I usually do and it works for me. I just have to remember to do that.

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I forgot my sugar and added it to the water after the lye and ended up with big bits of soft crack stage lye candy floating in it!

I just put my sugar in my water and let it dissolve before I add the lye to it. I don't bother with heating the water first and then letting it cool. Unless you're adding a crazy amount of sugar, the water should dissolve the sugar without needing to heat it first. At least, that's been my experience.

Going back to CPOP - I've recently starting doing "twice baked" soap - it really helps to get soap out of the mold! The soap goes through a second gel stage. I do wonder if that could speed up the curing process, but I haven't yet done a blind test. I accidentally gelled a soap for 8+ hours once. It turned out fine but I don't know if that was just luck or what. If you decide to test this method, I recommend taking some steps to protect your oven - such as putting your soap mold inside a large glass casserole dish. I cover a cookie tray with a dish towel and put my mold on that.