Soap soft after 48 hours.. what did I do wrong?

[CosmoGirl]

hi there! I am a long time lurker, first time poster. I have been using the cold process method for several years and few [roblems. My latest batch of soap has been more troublesome however so I would love some advice. I made a 500g batch of soap using the following recipe

35% (175g) sunflower oil
30% (150g) coconut oil
30% (150g) oive oil
05% (25g) castor oil
water was 190 g and lye was 70g, superfatted to 3%.

Batch did not take an unusually long time to trace, it reached the consistency of cake batter quite quickly, and I had added 10g lemongrass oil at a light trace. I wrapped it nice and warm in towels, expecting to be able to unmold as usual the next day. It is still soft though after two days, much too soft to consider trying to remove it from the silicone mold. I am really puzzled about what went wrong. Is it too high a percentage of soft oils? I am limited to the oils that are economical in my area, so pretty much tied to coconut oil as solid fat. I find above 30% of coconut oil to be drying. Have I used too much water? I have never experimented with other lye concentrations and am nervous about doing so. Could some sodium chloride help with my next batch? It is frustrating as (I think!) I did everything right, and this is first batch I have had problem with. I would love some input and will be grateful for all advice!

 

[Hazel]

You didn't do anything wrong. It's just going to take a little longer to get hard because of the sunflower, olive and water. Sunflower oil doesn't really help with hardness so you're just going to have to be patient. I love sunflower oil in soap but I generally keep it below 15%. It looks like it's going to be a nice soap but you'll want to watch for DOS since you have such a high percentage of sunflower oil. Next time I'd recommend you use a water discount. You can either type 29 into "Water as percent of oil weight" box or just click on the lye concentration and use 33%. You could also use a 40% lye concentration if you feel confident about using a stronger lye concentration.

You could also reduce the sunflower percentage, increase the olive percentage and superfat. I'd still suggest a water discount with the recipe below.

50% olive oil
30% coconut oil
15% sunflower oil
5% castor oil

You can also use a higher superfat and increase the percentage of coconut oil. A higher SF makes coconut less drying. One of my favorite recipes is a salt bar with 80% coconut, 15% sunflower and 5% castor with 20% SF.

 

[CosmoGirl]

Thanks so much for getting back to me. I mainly increased my sunflower oil so drastically as it is the cheapest oil I have, and budget is my biggest concern. I'll try your recipe today though, thanks! I am not sure I am confident enough to experiment with the lye and water amounts, I will wait and see how the lowered amount of sunflower oil affects recipe first. Patience I have a lot of... my favourite soap is 100% olive oil with no water discount.. it takes a very long time!! I just figured that the coconut oil would work its usual hardening magic. Thank you!

 

[Seifenblasen]

I am not sure I am confident enough to experiment with the lye and water amounts, ...

Water doesn't really do much in soap making other than as a medium to dissolve the lye, as lye is not exactly soluble in oil. Most of the water eventually evaporates in the curing process. So within reasons, reducing the amount of water in the formula does not change much other than you end up with a harder soap in less time.

The amount of lye is a completely different thing. You do not want to experiment too much; stick to the range given by the lye calculator.

 

[CosmoGirl]

I should have said lye concentrations rather than lye amount, I would never deviate from the amount stated on soapcalc.

About water, I thought it was necessary for chemical reaction, beyond as a solvent for lye. The fat molecules are composed of glycerin and fatty acid tails. I am not the bestest in world at chemistry, but as far as I am aware, the water is necessary to "pull apart" the fat molecules by hydrolysis. This leaves free glycerin and the fatty acids then react with the lye to form soap molecule. Am I totally wrong about this? That is why I am hesitant to change water amounts, due to the fact I worry it will result in too much unreacted lye.

 

[Seifenblasen]

NaOH has a molecular weight of 39.997, and water has a molecular weight of 18.015. In your formula you are using 70g of lye, 190g water, so that comes up to roughly to 1.75 mol of NaOH and 11.16 mol of water. I believe you need 3 molecules of NaOH and water for each molecule of fat, and in this case you have way more water than NaOH - roughly 6 times more than needed for the chemical reaction.

While you do not necessarily need all that water in the chemical reaction, NaOH is soluble in water, at 20 degrees C, at a rate of 111g /100ml (or gram) of water. So to dissolve 70g of lye, you need roughly at least 78g of water. And of course, there are safety reasons to consider as you probably don't want to play with too strong a NaOH solution.

The water discount Hazel suggested is 29% of the oil weight, which will give you 145g of water, almost twice as much as the amount required to completely dissolve the NaOH at room temperature. So I say go for it! :wink:

 

[Hazel]

Wow! I'm impressed with your knowledge. I suggested the 29 because I thought it would give CosmoGirl about 33% lye concentration. I just double checked and realized this isn't a good way to change the lye concentration.

@ CosmoGirl -

I'm sorry I told you a bad way to do it. It would be more accurate just to use the lye concentration box to adjust the water amount.

 

[Seifenblasen]

Actually, instead of doing through all the calculations every time, I normally use Majestic Mountain Sage's lye calculator because it gives a range of water and you can play with and still stay very safe:

http://www.thesage.com/calcs/lyecalc2.php

 

[booboo]

Actually, instead of doing through all the calculations every time, I normally use Majestic Mountain Sage's lye calculator because it gives a range of water and you can play with and still stay very safe:

http://www.thesage.com/calcs/lyecalc2.php

Thats what I use. When I'm using a lot of soft oils I use the lowest % of water, when using harder oils I use a higher %,
it was recommended to me a long time ago but I cant remmember why
If I am unsure about a recipe, first attempt is made with the highest % of water.

 

[CosmoGirl]

Thanks guys for getting back to me! Made another batch of soap and it turned out a lot better. This time my recipe was:

50% olive
30% coconut
15% sunflower
05% castor
Tea tree and lemon EO's

I used a 33% lye concentration as recommended.. I can't believe I didn't try that sooner! Reached trace a lot quicker, and was ready to unmold in about 36 hours. I think it would have hardened up sooner, but in winter I find it takes a bit longer.

Cheers for tips, I'll definitely be using that recipe and lye concentration.. it seems to be a great balanced recipe, really pleased.

 

[Hazel]

Thats what I use. When I'm using a lot of soft oils I use the lowest % of water, when using harder oils I use a higher %,
it was recommended to me a long time ago but I cant remmember why
If I am unsure about a recipe, first attempt is made with the highest % of water.

Soft oils take longer to harden so you don't have to leave them in the mold as long when you use a lower water amount. The first time I attempted a bastile batch I didn't know to discount the water. Days and days in the mold.

 

[booboo]

Thats what I use. When I'm using a lot of soft oils I use the lowest % of water, when using harder oils I use a higher %,
it was recommended to me a long time ago but I cant remmember why
If I am unsure about a recipe, first attempt is made with the highest % of water.

Soft oils take longer to harden so you don't have to leave them in the mold as long when you use a lower water amount. The first time I attempted a bastile batch I didn't know to discount the water. Days and days in the mold.

Been there.. done that

 

[Lindy]

Something else that helps harden soap up faster is Sodium Lactate. When I make my Hemp Soap I add 2% SL and it does set up faster for cutting and being ready for sale. I've had Hemp Soaps take 6 - 8 weeks to cure on me :? I'm not quite that patient.... :|