How do I get my soap to harden in the mold

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I've tried several recipes, and it seems to take my soaps forever to get hard enough to unmold. We have our air conditioning on which should remove excess humidity. The top hardens, but the sides and bottom stay soft. I unmold them after a week, cut them and leave them out to dry and they are fine. Any suggestions?
 
I've tried several recipes, and it seems to take my soaps forever to get hard enough to unmold. We have our air conditioning on which should remove excess humidity. The top hardens, but the sides and bottom stay soft. I unmold them after a week, cut them and leave them out to dry and they are fine. Any suggestions?
I would recommend posting your recipe(s); without knowing what's in your recipe, it's a little difficult to offer suggestions.
 
I would recommend posting your recipe(s); without knowing what's in your recipe, it's a little difficult to offer suggestions.

Here's one:

Olive Oil - 40%
Coconut Oil - 25%
Palm Oil - 25%
Sweet Almond Oil - 5%
Castor Oil - 5%

Here's another:

Coconut Oil - 25%
Palm Oil - 25%
Canola Oil - 25%
Olive Oil - 15%
Sweet Almond Oil - 6.9%
Castor Oil - 3%
Vitamin E Oil -0.1%

Thanks for your help
 
Looking at the oils you posted, nothing really jumps out as being a potential problem. In order to help, we need your full recipe and process, including amount of lye, amount of water, temperatures when combining, and what FOs, EOs, or other additives were included. We also need to know what type of mold you are using. It sounds like a loaf mold, but I don't want to assume.

It could be that you are using too much water, or not enough lye. Perhaps the soap needs some help (additional heat) to saponify more quickly - that can be an issue with cavity molds, but usually not so much with loaf molds.

But we really can't pinpoint the issue unless you post all the deets. :)
 
Looking at the oils you posted, nothing really jumps out as being a potential problem. In order to help, we need your full recipe and process, including amount of lye, amount of water, temperatures when combining, and what FOs, EOs, or other additives were included. We also need to know what type of mold you are using. It sounds like a loaf mold, but I don't want to assume.

It could be that you are using too much water, or not enough lye. Perhaps the soap needs some help (additional heat) to saponify more quickly - that can be an issue with cavity molds, but usually not so much with loaf molds.

But we really can't pinpoint the issue unless you post all the deets. :)


Sorry, had to run through a calculator again, here is the recipe:

LYE & LIQUID AMOUNT
Lye (Sodium Hydroxide) 5.47 oz
Percentage of liquid 12.23 oz
Total 17.70 oz
OIL & FATS AMOUNT %
Olive Oil - Pure 5.85 oz 15.00%
Canola Oil, High Oleic 9.75 oz 25.00%
Castor Oil 1.17 oz 3.00%
Palm Oil 9.75 oz 25.00%
Coconut Oil 9.75 oz 25.00%
Sweet Almond Oil 2.72 oz 6.90%

Used a silicone loaf mold. Thanks for your help
 
Sorry, had to run through a calculator again, here is the recipe:

LYE & LIQUID AMOUNT
Lye (Sodium Hydroxide) 5.47 oz
Percentage of liquid 12.23 oz
Total 17.70 oz
OIL & FATS AMOUNT %
Olive Oil - Pure 5.85 oz 15.00%
Canola Oil, High Oleic 9.75 oz 25.00%
Castor Oil 1.17 oz 3.00%
Palm Oil 9.75 oz 25.00%
Coconut Oil 9.75 oz 25.00%
Sweet Almond Oil 2.72 oz 6.90%

Used a silicone loaf mold. Thanks for your help
You recipe came up .1% short by percentages, so I used the weight amounts instead to enter it into the calculator. Your lye concentration came up around 30%; that would be a lot of water for me, especially for a recipe that is 50% soft oils. You might try raising the lye concentration to 33% and see if that helps. You could also try dissolving 1 tsp salt PPO in the water before adding the lye. Salt helps the bars harden up more quickly and release from the mold. You can also use sodium lactate if you have that, or vinegar as a water replacer (but be sure to adjust the lye to account for the vinegar).

I'd also recommend making much smaller batches of soap than 5 pounds at a time. That is a LOT of soap, especially when you are still working on the recipe. Try using smaller molds to make 1-2 lb batches at most.
 
Last edited:
Since water can’t evaporate through the sides and bottom of a silicone mold, remove the loaf after a day even if the middle is still soft.
 
I would first start with reducing some of your water. 12.23 oz water for 5.47 oz lye is a lot of water. A 33% lye solution or 10.94 oz water for this amount of lye I consider average amount of water by most soap makers. Many use a lye solution of up to 40% which would mean 8.2 oz water for the 5.47 oz water. That change may be the only thing you need to be satisfied.
 
Maybe the soap batch didn't get to emulsion? I had that one time and it was too soft even after two days. Did you see the trace?
How long has the soap been in the mold?
 
Yes, your silicon mold probably has some part in that. But you still have a really high water amount. I unmold my recipe from my silicon molds before I go to bed the night it is made. If it is fully gelled, I usually go ahead and cut it (about 15 or so hours after pouring). If you don't feel you can do that safely, you need to look to your water amount.
 
Thanks everyone for your suggestions. Something I should have clarified before, it is the bottoms and sides of the loaf that remain soft. I'm thinking the silicone is the culprit here. Thoughts?
Personally, I don't think the silicone mold is causing your soap to remain soft, maybe a little sticky perhaps but not soft on those sides. You might want to consider using Sodium Lactate solution at the rate of 1 teaspoon per pound of oils used. It helps the soap to harden faster and makes the bars slightly longer lasting too after the standard curing time of 4-6 weeks.

I have found that regardless of what type of mold I have used, whether is was a freezer paper lined wood mold, silicone mold or even a 9x9 casserole dish. That whichever sides were not exposed to the air will always be slightly tacky aka sticky, but one exposed to the air become firm to the touch in a few hours.
The only soap I do get soft exteriors on is the dual-lye shave soap I make in a cylindrical PVC mold lined with clear acetate sheets, but the softness is due to the dual-lye process not the mold itself.
 
I agree with the others that it’s not the silicone.
you’d be amazed at the difference between 30, 31, 32 and 33% lye concentration. Also, the level of trace makes a huge difference to some recipes. If you pour at emulsion it can slow up curing.
 
Something that isn't related to the softness or hardness of your soap, but that I picked up on in your comment, that you had to re-run your recipe through your lye calculator.
I don't know if you didn't keep a hard (paper) copy of it, or didn't save it to a note app, or just the lye/soap calculator memory. Whatever the reason, it's really, truly, important to keep some kind of record of what your recipe is, in quantity of every part of it: oils, water, lye, fragrance oil, essential oils, your grandma's stole, superfat percentage, etc.
You think, (ok, I thought) it'd be easy to remember what you (I) did, or how much salt or sugar or honey you (I) ended up actually using in a recipe, 2 hours later. Nope. In the aftermath of the panic, everything was a blur. I learned to put down notes on the fly on a separate notebook from my "formal" Soap Notebook. The one looks like it's been through a war, the latter is all dressed up and ready for its 10 year school reunion.
Just saying, if no one's mentioned it yet.
And welcome to our addiction!
 
You guys are geniuses! I changed the lye to 32% and the loaf I made yesterday morning was ready to be cut by midnight last night. Popped right out of the mold. Thank you all so much!
LOL! It really has nothing to do with being geniuses; actually the tried and true ratio of 2 parts water to 1 part lye has been around for decades. Yeah, some folks fiddle with the ratio, usually do to some oil blends they're using.

With my shaving soaps I use a 23% lye to 77% water ratio because I need the mixture to maintain pourability into a 3" x 24" PVC Round mold. It's sticky when it comes out of the mold, but two days air exposure and it's ready to slice and package.
 
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