Increasing Coconut Oil Dishsoap's suds?

[Liquidsoaper]

Is there anything I can add to Coconut Oil LS to increase its suds (and sud stability)––but not dilute its cleaning strength? Ideally I could add something that increases suds production and cleaning power at the same time...

Right now, the dishsoap's formula is just:

76 degree Coconut Oil - 395 grams​

KOH - 113 grams​

Water (distilled) - 1406 grams​

I'm a little confused on which fatty acid(s) are actually responsible for suds. I've been comparing different fatty oils with Soap Calc's guide (the spreadsheet is here). They measure attributes by the amount of:

Lauric + Myristic = Cleaning Ability​

Lauric + Myristic + Rincinoleic = Bubbly Lather​

I'm not sure how accurate their guide/spreadsheet is...

• From what I've read, Rincinoleic acid (like Castor Oil) doesn't create much suds. It provides sud stability – so I was planing to add it to the formula at 2%.
• Do Lauric and Myristic act differently from each other? The Soap Calc guide combines the two to measure a fatty oil's cleaning power and suds, but is one acid a stronger cleaner than the other? Does one produce more suds than the other?

For reference, 76 degree Coconut Oil is:

~48% Lauric Acid​

~19% Myristic Acid​

Do I need to increase the amount of Lauric acid to get more suds? Or Myristic? Or something completely else?

Thanks!

 

[DeeAnna]

You can't separate lauric acid from myristic acid if you're making soap with coconut oil, so the matter is moot, isn't it? Or are you thinking about making soap using the individual fatty acids instead?

Most handcrafted soap makers make soap from fats, not pure fatty acids, so separating the effects of the individual FAs is not especially useful, which is why you're not finding much info about the behavior of soap made from pure fatty acids.

This question comes up fairly regularly. I'm going to cut to the essentials and tell you that adjusting the relative proportions of myristic and lauric acid in your soap won't solve your goal of getting more lather and cleansing ability.

The bubbles created by any soap in a dilute solution of water and soap are unstable and don't last very long.

Soap high in shorter chain fatty acids, such as lauric and myristic acids, make lather with large bubbles -- it's called "flash foam" by soap chemists. This type of lather has an a shorter lifespan compared with lather from soap high in palmitic, stearic, and oleic acids.

Soap made from these longer chain fatty acids produce lather that has smaller bubbles. These bubbles are more stable than bigger bubbles so theoretically they should last longer.

Unfortunately, hard water minerals interact with soap to form soap scum. When you dissolve soap in a basin of tap water, there's enough hard water minerals even in the softest of water to quickly reduce soap's lathering ability and cleansing ability to near zero.

Modern dishwashing cleansers like Dawn are not based on true soap; they're formulated from synthetic detergents. Syndets don't react with hard water minerals to form soap scum, so they retain their cleansing ability. They also produce more lather than soap when highly diluted in water, and that lather is more stable.

You could try a blend of true soap and syndets and see how that would work. But you are asking for a miracle if you want true soap alone to lather and cleanse well when used as a dishwashing cleanser.

 

[Liquidsoaper]

Thanks @DeeAnna. Sorry about the redundancy. Interesting stuff about the bubble size/stability in relation to chains and metals' capacity to destroy suds production.

Agreed, natural formulas can't compete with Dawn's detergents. Still, I'd like to try my hand at creating a suitable dishsoap substitute using a 'true-soap' formula ( + a chelator) ( + a preservative, if needed). It sounds like I need to take a step back, work on a chelator, then reevaluate Coconut Oil's sudsing ability. My hard water is probably screwing with my soap's abilities.

I guess I'm also just trying to understand the science (and validity) behind this Soapcalc spreadsheet's method of adding up certain fatty acid contents to rank a fatty oil's attributes. I started with 100% Coconut Oil because it's the highest scoring fatty oil for the 'Cleansing' and 'Bubbly' attributes. Is the spreadsheet's ranking accurate?

Is a fatty oil's cleaning strength really a matter of Lauric acid + Myrstic acid content (chelation aside)? Do both acids have equal cleaning abilities and 'flash foaming' amounts? *I'm not trying to use isolated fatty acids––I want to use fatty oils. I just want to know what to expect from a fatty oil's composition so I can make the strongest/sudsiest true-soap formula.

For example – If Myrstic acid is a better cleaner/sudser than Lauric acid, I'd switch from Coconut oil to Nutmeg butter.​

 

[DeeAnna]

"...It sounds like I need to take a step back, work on a chelator..."

Uh, no, not really. Not sure why you've decided a chelator is the solution to your problem. I'll just say you cannot physically pack enough chelator into soap to make it work the way I think you want it to work.

A chelator can treat the hard water minerals in only a limited amount of water. If you're spot washing -- meaning put some soap on a wet sponge to directly wash an item -- a chelator can be helpful because the amount of water to be treated is minimal.

But you cannot add a chelator to soap and expect the chelator to treat a sink of water (or washing machine or bathtub). Don't have unrealistic expectations about this.

If you want to treat the hard water minerals in larger amounts of water, you need to add a separate water softener product such as washing soda or borax or use a whole house water softener or both. Or use rainwater or distilled water for washing.

More: Chelator limitations | Soapy Stuff

"...Is the spreadsheet's ranking accurate? ...

Yes and no. The "cleansing" number isn't truly a measure of whether a soap can clean or not. ALL soap can clean, even soap with a zero cleansing number. This number is merely the combined percentages of lauric and myristic acid.

Lauric and shorter-chain fatty acids (FAs with 12 carbon atoms or fewer in their backbone) are highly efficient at quickly emulsifying fats than FAs with more carbon atoms in their backbone. The lauric acid content is the main reason why coconut oil soap can be so drying and irritating to the skin, but it's also the reason why coconut oil soap is often used for houshold cleaning.

Soapcalc's numbers do not account for FAs with fewer than 12 carbon atoms. Most fats used for soap making generally don't have a lot of shorter-chain FAs, so it's a reasonable simplification, but it's still a simplification.

More: Soapcalc numbers | Soapy Stuff

 

[HowieRoll]

I've used 100% Coconut Oil LS for over 3 years to clean dishes (and the house). The fact it doesn't have as long-lasting/durable suds as a syndet (i.e. Dawn) is something I've accepted as a trade-off to using a homemade soap product. But it doesn't mean I don't still poke around to try finding something to add some "oomph"! So I read your post/questions with interest.

My first batches always included 5% (oil weight) of sugar, either granulated or powdered. And now that I think about it, I have no way of knowing if this actually helped the lather because I've never made a batch without it, so hmmmm.

The most recent batch I made included 3.5% (oil weight) of sorbitol, as I was curious to see if that might add a little something-something. And you know, if anything, it may have reduced the lather a little bit. Well, either that or, comparatively, using the regular sugar increased lather a little bit, not sure. But just the other day my husband even mentioned he didn't feel this soap batch lathered as well and he's less inclined to scrutinize such things (as opposed to me, who mentally steps into a testing lab every every time I'm using a homemade product).

Anyway, years ago I bookmarked this thread that, starting at post #16, mentions using potato water for liquid soap. Even though I've thought about doing this for a few years as an experiment I haven't, and really have no idea if scientifically, or anecdotally, or cosmically, or whatever-ally it really does boost lather, let alone cleaning ability. But thought I'd throw it out there.

https://www.soapmakingforum.com/threads/dish-washing-liquid-soap.60601/