Minimum Longevity Number

[MellonFriend]

I've had some trouble with what I am assuming is the longevity numbers of my soap recipes. At the sink in our house where there is the most traffic, all of my bars end up getting soggy and squishy. I recently made a bar with lard and it was a lot better, but still not what I would like. My longevity number of my recipes were within the recommended range, but it's just not ideal. What number do you generally shoot to be above in for longevity in the lye calculators?

 

[DeeAnna]

This number is the combined percentage of palmitic and stearic acids in your recipe. I normally shoot for 30% to 35%. I recall others saying they go for 35% to 40%.

If your soap stays soggy because it can't drain and dry well, even a soap with a high longevity number can't overcome that problem, although it's going to perform better than a soap with a low value.

There's such a thing as too much of a good thing -- if this number gets too high, the soap won't lather well.

 

[Ladka]

... There's such a thing as too much of a good thing -- if this number gets too high, the soap won't lather well.

Will it lather better with the addition of sugar in spite of a high combined percentage of palmitic˛&stearic acids?

 

[Mobjack Bay]

I like 29-30, maybe 31. I’ve made batches of 33 longevity for testing, but never gravitated towards them when I had them in the shower. I think it was mostly because of the way they felt in my hand - too edgy! Maybe that explains why commercial soaps, which tend to be very hard, are often shaped to have smooth contours. My 33 soaps made a lather I would call creamy, rather than foamy or bubbly, even when I added sugar and/or aloe. I was probably using around 20% for the CO. I would need to check my notes to be sure.

 

[DeeAnna]

Will it lather better with the addition of sugar in spite of a high combined percentage of palmitic˛&stearic acids?

I suppose so, but I really have no idea. I've never tried it.

 

[KiwiMoose]

I aim for high 30s - and there's not really any way to make mine harder/less mushy unless I start using animal fats. Perhaps try lowering your superfat to 3%, and dissolve a teaspoon of salt into your water before mixing the lye?

 

[MellonFriend]

Thanks everyone for the suggestions.

I have been thinking about reducing my superfat to 3%. I'll give that a shot. Honestly, I've had trouble formulating recipes that crack 30 in the longevity category. I'm not really sure why. I have olive, sweet almond, shea butter, cocoa butter, castor, coconut, and lard at my disposal. I've been staying away from Palm oil, so maybe that has something to do with it. What I don't understand is how recipes high in olive oil are any good then. Does curing a bar longer help increase the longevity or just the hardness?

 

[KiwiMoose]

Why not try 30% lard, 10% Cocoa Butter, 15% Shea, 20% CO, 20% OO and 5% castor. Out that into a calculator and see what comes up for longevity.

 

[ResolvableOwl]

What I don't understand is how recipes high in olive oil are any good then.

That's because soap profile numbers are just that … numbers. They're quite simplistic sums of some fatty acids, with the best intentions, but they just cannot reflect all details of the very intricate properties of oil blends, let alone in a quantitative manner.

High-olive recipes (castile & friends) do get hard (note how the hardness number of calulators underestimates the actual hardness), but they're not famous for being very long-lasting – in this respect, the calculator numbers are even helpful to not rely too much on the apparent hardness that well-cured olive soap brings.
Still, the longevity/hardness numbers don't distinguish between, say, olive and soybean oil – which is about as weird as it sounds. They are of some use, but they won't tell you by themselves about their limitations.

On top of that, they're not complete. For one, the superfat thingie. Then, oils like cupuaçu or sal butter bring “minor” FAs that contribute to hardness, but aren't recognised by most soap calculators. The worst is soy wax (vegetable oils hydrogenated to a degree that the manufacturers usually aren't eager to disclose) – you have to guess/tinker around until you've got an understanding of its behaviour.
Then there are general process-dependent issues. CP/HP? Gelling/not gelling? Water content? EOs/FOs? Dual lye? Sugar/sorbitol/goat milk/coconut milk/rice? I've found that soaps with palm as the only hard oil will usually harden up nicely, but sometimes not; but even if they don't, they may or may not have a more satisfactory longevity than expected from the softish touch.

I personally (with my usual notorious choice of hard oils) try to aim at a longevity number below 35, since above that, I've witnessed false trace once too often . “Level-up” from the calc numbers is a deeper understanding of the actual FA profile. My (current) ideal soap is about 7–11% stearic, and about twice the palmitic.
In your case 60% lard, 25% olive, 10% almond, 5% castor. (Yes, it's not a mistake I've left out coconut. Soapcalc numbers really do what they can to trick people into above-than-average levels of coconut, but not me .)

 

[soapman5]

I've noticed that soaps with more stearic acid than palmitic acid takes longer time to lather up. Which is logical due to the fatty acid structure. Also, the lather is more creamy with stearic acid.

I've tried with sugar and polyols and it's a bit better.

So, for easier lather, try to increase the palmitic acid

 

[MellonFriend]

Why not try 30% lard, 10% Cocoa Butter, 15% Shea, 20% CO, 20% OO and 5% castor. Out that into a calculator and see what comes up for longevity.

That sounds good. I am actually trying to get away from cocoa butter, I'd just like to not have to buy so many oils. But I still have some left so I may try it out.

 

[MellonFriend]

I'm thinking about trying this at 3% superfat:

It doesn't fall into Owl's steric/palmitic ratios. . . I also know that some people don't like 10% castor for stickiness, but I feel like I want to give it a shot. I was also looking to lower my cleansing properties since it is very dry here in the winter.

 

[ResolvableOwl]

Who has told you to believe what I'm saying?

It's a fine recipe. You can only better understand what you like or not with a recipe, by trying out by yourself. Go for it!

ETA: I'm very curious how you'd experience the increased castor level. The few times I've strayed from the true and tested 5% rule, there were always other odd things in the soap, that blurred the judgment of moderately elevated castor levels.

 

[Tara_H]

I'm thinking about trying this at 3% superfat: View attachment 62011

It doesn't fall into Owl's steric/palmitic ratios. . . I also know that some people don't like 10% castor for stickiness, but I feel like I want to give it a shot. I was also looking to lower my cleansing properties since it is very dry here in the winter.

I was playing around with the calc today trying to get a recipe with a good percentage of lard and ended up with a graph rather similar to yours with 70% lard and then 10% each of coconut, castor, and tallow.
Not necessarily recommending that recipe (yet) since I haven't actually tried it, but I was also aiming for a low cleansing number so may be a useful comparison.
Hopefully tomorrow I'll get to make soap with it

 

[AliOop]

I was playing around with the calc today trying to get a recipe with a good percentage of lard and ended up with a graph rather similar to yours with 70% lard and then 10% each of coconut, castor, and tallow.
Not necessarily recommending that recipe (yet) since I haven't actually tried it, but I was also aiming for a low cleansing number so may be a useful comparison.
Hopefully tomorrow I'll get to make soap with it

I regularly make something very similar, only I keep the castor down to 5%, and up the CO to 15%. Makes a very nice bar, IMO, especially if you add some form of sugar or starch for more bubbles, and give it a good long cure. Eight weeks and they are divine!

 

[gww]

aliOop

Eight weeks and they are divine!

Good to know as I have 24 lard bars about a week in with the co at 20 percent and castor at 5 percent but no sugar.
Do you have a suggestion of approximate sugar per pound of oil for my next rounds?
The only sugar I ever added was dissolved with water reduced from the lye and added to the oils before the lye mixture was poured in. Suggestions?
Thank you
gww

 

[Zing]

Good luck to you. I am on a years-long quest for formulating a harder bar so welcome to the club. The experts and scientists have weighed in so I'll just 2 non-fatty acidy things. In my house, these have been a game changer and I frequently add them to gift baskets:
https://www.amazon.com/Snowkingdom-...t=&hvlocphy=9019664&hvtargid=pla-872238703885 Also, the high traffic area in my house is the shower where I have 3 soaps on rotation.

 

[MellonFriend]

Maybe I'm not curing my bars long enough either. I've been testing them at four and six weeks and I just two days ago tried a bar that just turned three months old and I think it was a lot better than it was at four and six weeks.

 

[AliOop]

@gww Since you used 20% CO, plus the castor oil, you should have nice bubbles after a good cure. If you want to increase them by adding sugar next time, the typical sugar addition is anywhere from 1-3 tablespoons per pound of oil, or 2-3% of your total oil weight.

I personally have switched to sorbitol and use that at 1% of total oil weight. It makes fantastic bubbles, and since I use less of it than the sugar, it is very cost-effective, as well. But I understand the desire not to have extra ingredients around, too, and simple household sugar works just fine if you want to try that.

@MellonFriend IMO, high-lard bars are really best after a longer cure: eight weeks is really a turning point for mine. They are even lovelier after 12 weeks!

 

[gww]

AliOop
Thank you for the response. I have a two week old pure lard in my basement bath and it is not loads of suds but seems to clean well enough and I hear they get better with time as well. I am not mad at how that works for myself.

I was just thinking of pleasing pickier people around me and also not be embarrassed when I give my family some bars. I am cheap and trying to keep it simple since my wife is not yet that enthused and she will not appreciate me spending too much just to rot or give away.

I got bees and could use honey instead of sugar but read that it is a little trickier and sugar sure seems easy the one time I did it on liquid soap.

I thank you for your answer as well as giving me an alternate route and your reasonings for it.
Cheers
gww