Speed up drying/curing time of CP soap?

[DeeAnna]

"...In an objective rather than subjective way, I mean ... can I assume that my soap is cured when its weight (total of all the now cut pieces) reduces by about half the water weight (about 115 grams)? ..."

Cure is not just about water evaporation, so the strict answer is "no." It's also about improvement in lather quality, skin feel after washing, and longevity. I don't know how you can determine some of these qualities in an utterly objective way. Even commercial soap makers don't have that all figured out.

It is true that many soaps made with a blend of fats (and thus a blend of fatty acids) are going to be cured enough in 4-8 weeks to please most people. That also happens to be about the time when the weight loss slows substantially, so measuring the rate of weight loss is a simple, fast way to monitor soap. But this rule of thumb that does not invariably hold true -- a slowing rate of weight loss doesn't always mean the soap is sufficiently cured and performing at its best.

The soap that taught me this fact was a soap very high in lard (stearic and palmitic acids). It did not lather well a month or two after making, but was a very pleasant soap to use at 1 year. If I decided weight loss was the only basis for determining it was sufficiently cured, the soap would have ended up in the trash. It almost did anyway, but I'm glad I gave it a final chance to prove its worth.

 

[lsg]

I agree with DeeAnna; curing is more than just moisture evaporation. Give your soap a good 4 weeks to cure. Six weeks is even better.

 

[tlsweet]

I have to agree with many of the more experienced soapers comments listed throughout this lengthy thread.
I've been making soap for 6 months now. I've found using a 2:1 lye to water mixture helps the soap release from the mold quicker. However, it doesn't make it cure any faster. I've tried bars of soap after 6 weeks, and later came back another month or two to find that same soap better. For me that meant it created more lather and was more creamy.
Lesson Learned: Wait at least 6 weeks.

Teena

 

[hoegarden]

CPOP or ITMHP is the same thing. You make the soap, bring it to trace, pour into your mold, then put in a warm oven (170 degrees) for 1 hour. Turn the oven off and leave it there overnight. By the next morning, the soap should be ready to cut. If you followed a soap calc correctly, this should be safe to sell after one week.
You really should wait longer as more water evaporates, but if you can't it's ok after one week.

Irena

Will this be good for milk soap too?

 

[shunt2011]

Will this be good for milk soap too?

Soapbuddy hasn't been here in some time. I personally don't do it with my milk soaps. Due to the sugars in the milk it can cause overheating and will also darken the soap a bit more than normal gel. I just insulate them well with towels and if need be a heating pad underneath (during the winter).

Some prefer to not gel their milk soaps at all.

Also, when I do use the oven, I just preheat it and turn it off when I put the soap in the oven and just leave it.

 

[DeeAnna]

Don't use that method for CPOP that Soapbuddy described. It was common a few years ago, but the soap gets too hot and that can cause problems. Shari's (Shunt) advice works better and has fewer side effects. Milk soap is likely to darken with CPOP, so keep that in mind if you want to keep the soap as light in color as possible.

 

[MullersLaneFarm]

Will this be good for milk soap too?

I do gel my milk soaps (100% milk in lye solution, all I've made for 16 years) using heavy wool blankets, however that is only when using my 9 lb & 12 lb slab molds.

I do not insulate (or use CPOP or ITMHP) when using my log molds due to over heating.

 

[IrishLass]

As with MullersLaneFarm, I gel my milk soaps, too.... and because I soap my milk soaps with a 33% lye concentration (just the same as I do with my non-milk soaps), I use my oven to ensure that I get a full (instead of partial) gel.....but not in the way described by soapbuddy. Years ago, I used to do CPOP in the way she described, but the results were not the best they could be (pock-marked soap, oil leakage, etc....).

As I (and many others) eventually learned the hard way, an oven temp of 170 degrees F for 1 hour is overkill unless you are HPing and giving your batter a thorough stirring every now and then. For CP soap batter that is just sitting stationary in its mold in a 170 degree oven without the intention of ever being stirred, it can spell trouble, if not total disaster (overheating, separation, volcanoing, etc...), even in soaps without milk.

When I CPOP, I preheat my oven to only 110F (achieved within 3 minutes of having turned my oven on), and I turn the oven off as soon as I place the soap in the oven and close the oven door. Sometimes I preheat as high as 120F before turning it off (with certain soap formulas), but never higher than 120F, ever. With a milk soap, I never go higher than 110F.


IrishLass

 

[MorpheusPA]

Thanks for that--I preheat to 170° and turn it off when I put the soap in. It works, but the soap often looks like the surface of the Moon.

That's fine for home use, but I'd rather gifts didn't do that!

 

[ngian]

For me the cpop method is inserting the wooden mold in the oven around 60-70°C and I'm watching it every 10 min and when it passes the full gel phase I close the oven and put the mold outside the oven.
This can be done in a 20 min time or even more (1 hour max) depending on the water amount in the recipe.

Otherwise if I just leave it for one hour without checking it, alien brains or small bubbles will be possibly made.

 

[Nanditasr]

It is true that many soaps made with a blend of fats (and thus a blend of fatty acids) are going to be cured enough in 4-8 weeks to please most people.

Does the temperature of the curing area affect the extent to which the soap will cure? Will there be a difference in cure time in summer vs. winter? Say, at 85 degrees F/30 C (my summer), vs. 65 F/18 C (my winter -- right now), or colder?

Are there any maximum/minimum temperatures to be observed while curing? Of course, in all cases, I assume the humidity is fairly low.

 

[Susie]

Does the temperature of the curing area affect the extent to which the soap will cure? Will there be a difference in cure time in summer vs. winter? Say, at 85 degrees F/30 C (my summer), vs. 65 F/18 C (my winter -- right now), or colder?

Are there any maximum/minimum temperatures to be observed while curing? Of course, in all cases, I assume the humidity is fairly low.

No difference in room temperature. The only thing that achieves cure is time. 4-6 weeks minimum. I do cure mine longer (6-8 weeks) in a more humid environment, just because I like the better lather it provides.

 

[Nanditasr]

Thanks, Susie. I had no idea that the longer cure with slight humidity actually adds to the lathering capabilities. Shall certainly bear this in mind, esp. considering that I am trying to reduce CO to 15 or even 10%, because I find it too drying.