CP soap too soft

[Kiwi_Brin]

very soft out the mould after about 3 days and still sqeezable after 2 weeks.
Recipe is:

canola oil 660g (72%)
coconut oil 200g (22%)
castor oil (6%)

Sf: 3%
lye conc. : 35%

distilled water 245g
KOH 10g
NAOH 115g (

sodium lactate at thin trace 20g (2.2%)

Rosemary EO 20g
used coffee grounds 20 g (this was too much in 1 lb of soap)

poured into log mould at thin trace

possible reasons for softness:
1. soap too young, dont use this one for a few months?
2. large amount of canola in recipe?
3. using canola over OO?
4. too much SL?
5. using KOH/too much KOH?

also i made my hydroxide and water solution in advance so it could cool to room temp but didnt get round to making the soap for 3 days. Is the solution ok to use after this long?

any thoughts appreciated!

 

[Arimara]

Check your numbers. Are they correct because they look quite off (ex- you made way more than a pound of soap)? Also, what is the purity of the KOH you used.

 

[Kiwi_Brin]

Sorry not 1 lb is 2 lb.

KOH is 95%

 

[KiwiMoose]

Hi Brin,

You have only 22% hard fat, so yes your soap will be soft. It is also not usual to use KOH for a general bath soap - just NaOH. KOH will make a soft soap. I would recommend increasing your hard fats to approx 40% of your recipe, although this is not always needed (as in the case of castile soap which is ALL soft oil). If you select soft oils that have a higher palmitic/stearic acid profile then this could also help: Olive Oil, Avocado Oil, Rice Bran Oil. I'm not sure that higher percentages of canola are recommended, but I will defer to more knowledgeable soapers on that one. I think it might tend to cause DOS (as does RBO, but I use that at no more than 20% successfully).

Have you thought of including either cocoa butter or Shea Butter in your recipe? This would make it harder.

Your current soap will probably be fine to use, but yes, it will need a long cure - probably over three months or more, and the canola may not age well, so i would recommend using it before it gets too old.

Sodium lactate I usually add to my lye water at about 1tsp per 500g.

Have you had a look at 'ideal' fatty acid profiles? https://www.modernsoapmaking.com/the-most-popular-fatty-acid-profiles-in-soapmaking/

 

[Arimara]

I ran this through SMF Calc and your superfat looks like it might be higher than what you input. Depending on the type of canola oil you used, I can't say how your soap might come out. Just give it some more time and if need be, put it in the oven @ whatever is equivalant to 140F over night to see if it might gel. Just remember, when you make a soap with more than 50% soft oils, the softness will stay around much longer and you will need to cure it longer too.

 

[DeeAnna]

A small amount of KOH is fine to use in bar (solid) soap. I use 5% KOH 95% NaOH all the time for my hard soaps. https://www.soapmakingforum.com/threads/dual-lye-castile.59747/

My personal soap recipe calc is showing a 5% KOH usage, but it's telling me the superfat is higher than the OP is claiming (more like 8%) and the lye concentration is lower (more like 33%). I didn't fiddle with the numbers very long, so those are rough numbers. More superfat and more water can contribute to softness in a higher linoleic soap like this, but that's not necessarily a given. The way the soap is made can contribute to the soap being overly soft.

I've never made a canola-coconut soap, so I can't speak with authority about this particular blend of fats, but having made a soap with HO sunflower and coconut oil recently, I can definitely say a high oleic fat like HO sunflower can make a firm bar soap with 5% KOH, 2-3% superfat, 33% lye concentration.

As to why the OPs soap has stayed so soft for so long ... I really can't say for sure. Higher superfat? The use of high linoleic canola rather than a HO version? Measuring error? Soap didn't gel?

 

[cmzaha]

Using SMF for the Calculator I find all the numbers come up close but the KOH requirement short by 9 grams. I always use dual lye but keep the KOH at 5% and always use HO Canola keeping it around 25% in my high palm recipe.

In the past, I have used regular canola in a high percentage, over 50%, with no issues so I really do not know why the soap is still soft unless there was a mismeasurement somewhere.

 

[Kiwi_Brin]

Thank you all for your helpful comments. I did put too much KOH into this batch the ratio should have been 4% KOH + 96% NAOH as the hydroxides. My 8% KOH might have been too much. It was a measuring error on my part.

I use Soapcalc but just entered my numbers into SMF calc and they provide slightly different water amounts (235g SC vs 240g SMF) and total lye (127g SC vs 129g SMF). Maybe because SC doesn't support mixed hydroxides.

Why does SMF increase the mass of the KOH above what you enter in the left hand side box? 4% KOH on the left provides a mass of KOH @ 95% purity equal to 5.8%. I think I will just use the 4% of total lye mass.

Im not sure what Oleic level the canola oil is but I will reduce its percentage in the recipe as recommended.

I recently made a batch with 1T Calcium Bentonite PPO - my hardest batch so far, so I will add that back to the next recipe.

Again, thank you all for your time!

 

[DeeAnna]

"...Why does SMF increase the mass of the KOH above what you enter in the left hand side box? 4% KOH on the left provides a mass of KOH @ 95% purity equal to 5.8%. I think I will just use the 4% of total lye mass...."

Whoa. Stop.

You're making a serious mistake. The calc is correct. If you really don't understand the chemistry, you should be trusting the calc's answers, not "fixing" the numbers because the "look wrong".

You CANNOT partition the alkali by weight (mass) alone. It has to be calculated based on molar amounts, not weight amounts. The short reason why -- 1 mole of KOH weighs more than 1 mole of NaOH, which is why the KOH weight is more than you think it "should" be.

Stick to using just one alkali or understand what you're doing. I suggest you read my article -- https://classicbells.com/soap/dualLye.asp If something is not clear in the article, ask me.