[Gunther]

@Belassi
I’d start with Sodium Salicylate, either by reacting bare salicylic acid with dilute NaOH, or by buying premade SS.

SS is way more soluble than Salicylic Acid.

You’d need to lower shampoo pH to match SA pka 2.97, to get 50% SA / 50% SS
So you’d get more than 50% soluble SS at normal shampoo pH levels
Compare that to 0% SS if starting with SA from the beginning.

Many commercial shampoos have SS
https://int.eucerin.com/our-research/ingredients/s/sodium%20salicylate

[Gunther]

@mikethair you’d want to:

1 keep detailed microbial testing records. Independent testing, if possible
2 A disclaimer about end customers having to provide clean bottles
3 use the maximum safe amount of preservatives, even redundant preservatives
4 a disclaimer about customers having to use the whole bottle by 1/2/3 months or so

all the above in case the bottle provided by the customer is contaminated.

Out of curiosity, where are you located @mikethair ?

[Gunther]

While Potassium myristate (from reacting Myristic acid + KOH) seems to be a bit soluble, Potassium stearate is likely insoluble.

Please read the study
The solubility of sodium and potassium soaps and the phase diagrams of aqueous potassium soaps

The only soaps that are even moderately soluble at room temperature are potassium laurate, myristate, and oleate, the potassium salt of acids from coconut oil, and the sodium oleate. The other sodium and potassium soaps of the saturated fatty acids require elevated temperatures for solution.
https://link.springer.com/article/10.1007/BF02645899

So you’re limited to Potassium hydroxide (to make Potassium salts), coconut oil, lauric, myristic and oleic acid.

With other oils, you may wait for the insoluble soaps to precipitate down, then draw the upper layer with just the soluble ones
but I don’t know if you’ll need a centrifuge for that.

[Gunther]

Please do all the above, as @Doreen has just stated

I believe that for ‘Soap’ you mean real soap made from vegetable or animal fats or oils saponified with Sodium or Potassium hydroxide, don’t you?

Please Google on how synthethic “soaps” can’t be legally called soaps anymore.

As for soaps separating
please read the study 
The solubility of sodium and potassium soaps and the phase diagrams of aqueous potassium soaps

The only soaps that are even moderately soluble at room temperature are potassium laurate, myristate, and oleate, the potassium salt of acids from coconut oil, and the sodium oleate. The other sodium and potassium soaps of the saturated fatty acids require elevated temperatures for solution.

https://link.springer.com/article/10.1007/BF02645899

https://www.researchgate.net/publication/225452149_The_solubility_of_sodium_and_potassium_soaps_and_the_phase_diagrams_of_aqueous_potassium_soaps

So it looks like you’re limited to saponifying Coconut oil just with Potassium hydroxide so it remains soluble.

You might saponify other oils (always with Potassium hydroxide), wait for the insoluble soaps to precipitate (although I don’t know if you’ll need a centrifuge for that) and draw the top water layer with soluble soaps.
I’ll surely add to costs so you’d want oils rich in Lauric, Myristic and Oleic acid, the ones soluble, as the study says.

[Gunther]

if it’s grainy it might be from particles coming out of solution as it dries.
Most likely water evaporates first, leaving water-soluble, but oil-insoluble compounds precipitating as fine powder.

While I’m biased against anything oily or greasy
you can try with fewer oils to see if it works, as you stated that single, thin layers work fine.

You can also try knocking out (removing) all water soluble ingredients except emulsifiers and solubilizers.
If it improves then the problem it’s in the water phase
if it doesn’t then the problem it’s in the oil phase.

[Gunther]

Check who the manufacturer is
reputable manufacturers keep tighter batch to batch quality standards, than generic ones.

It’s perfectly possible to switch suppliers (distributors) but both of them sell product from the same manufacturer.

[Gunther]

Perhaps only suited for really poor city areas or countries.

End customers will fear the retailer waters down the barrels, since they ain’t individually packaged and sealed.

I foresee no-plastic (steel?) sturdy reusable soap pumps and you buy the refills in glass bottles (no plastic as well). Interesting niche market with great upside potential.

[Gunther]

Wow that’s a really long list of ingredients
What’s the water % typically used?
Why not sharply lower all oil-solubles to make it lighter?

[Gunther]

@Belassi one last question
Did you ever get ALS/ALES to decompose with sunny Mexico temps?
I couldn’t find any scientific info on that.
Thanks

[Gunther]

too see if we can help
What was the name ofthe polish or its List Of Ingredients?

[Gunther]

You need to read the specs for that cups manufacturer.

[Gunther]

Is the coconut fragrance synthetic or natural-extract?

Maybe it worked so well because coconuts contain emollient esters and lactones:

http://beauty-review.nl/wp-content/uploads/2015/04/Final-report-on-the-safety-assessment-of-Cocos-nucifera-coconut-oil-and-related-ingredients.pdf

http://www.chemikinternational.com/wp-content/uploads/2015/06/chemik_2015_06-3.pdf

Did you get any complaint from customers triggering ammonia smell by shampooing their hair after using hair relaxers, dyes or alkaline neutralizers?

[Gunther]

Refractive index
and surface reflectance/absorbance would be a start.

[Gunther]

IMO it’s a bit hard to get cosmetic-grade sorbitol, but food-grades made by top companies are really good.

I personally liked Erythritol better than Glycerin or Sorbitol
better an emollient, yet not as sticky.

[Gunther]

@Belassi do you happen to have a specs sheet for a ALS/ALES preblend
where they list the % of ingredients?

 Plantaren APB and Texapon KD S03 don’t seem to list the percentages at all.

[Gunther]

Just check the paint cups specs
Paint, especially those meant to be sprayed are way thinner than shampoo
https://www.hallmach.co.nz/public/db_files/1504567179.pdf

[Gunther]

Yes, but you’d need something to compare flow-times to

either

 A. Reference fluid with the desired viscosity. Either lab-grade reference standards like these
https://www.sigmaaldrich.com/analytical-chromatography/analytical-products.html?TablePage=113813044
or a bottle of your favorite commercial shampoo (not very accurate, but allows a better comparison to commercial products).

 B. A professional viscometer with viscosity tables
like these
https://www.thomassci.com/Equipment/Viscometers/_/FORD-VISCOSITY-CUPS

You can always start smaller, say 6mm hole
and then drill it bigger, if flow is too slow.

[Gunther]

Benzyl alcohol is both
less irritating than the same amount of Ethanol
for preservation you’ll need less BA than EtOH, further reducing irritation.

Extrapolating from pharmaceuticals (may not fully apply to cosmetics as they’re often left open in the air, until it runs out):
If I’m not mistaken you’ll need at least 5% EtOH for proper preservation
while you can do fine with less than 1% BA.

[Gunther]

You can use any acid to rise pH as long as it is soluble and doesn’t interferfere with the other ingredients.
Even dilute Hydrochloric acid is sometimes used to rise pH in commercial stuff you drink, or inject (injectable pharmaceuticals).

So yes, you can use Lactic Acid if you want
just make sure it takes very little LA to rise pH, preferably less than 0.5%, best if less than 0.1%

Please be aware that some regulations limit the amount of LA allowed
‘lactic acid up to a maximum level of 2.5 % and a pH ≥ 5.0. ‘
http://ec.europa.eu/health/ph_risk/committees/sccp/documents/out284_en.pdf

Also read:

https://www.fda.gov/Cosmetics/GuidanceRegulation/GuidanceDocuments/ucm090816.htm#cos

https://www.cir-safety.org/sites/default/files/ahas.pdf

https://pdfs.semanticscholar.org/f1f0/ab5bbe2a0c516a98f51d135cbb4aadd7247d.pdf

[Gunther]

Ethanol can work fine as preservative
only advised if your formula already contains ethanol, I wouldn’t add EtOH just for preservation sake.

Extrapolating my experience with pharmaceuticals to cosmetics
You can use less Benzyl alcohol than ethanol (for the same preservation capacity), thus reducing irritation.

[Gunther]

Were you able to figure out what they meant by
DMAE + Amino acid compound?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4123624/

[Gunther]

Citric acid ain’t that acidic compared to lactic acid:

Citric acid pKa (1)  3.13
https://www.sigmaaldrich.com/catalog/product/sial/251275?lang=en&region=US

Lactic acid pKa  3.73
https://www.sigmaaldrich.com/content/dam/sigma-aldrich/docs/Sigma/Product_Information_Sheet/2/l1250pis.pdf

So, while theoretically citric acid could displace Sodium benzoate
to yield Sodium citrate + Benzoic acid
this reaction is very slow
and benzoic acid still holds preservative activity.

You can use lactic acid to increase pH if you want
just keep track of how much you use
as too much of it can increase sun sensitivity and cause unwanted exfoliation.

[Gunther]

@RenKB price depends if you want a “mechanical” or a digital one
You can start here:
https://www.labx.com/v2/adsearch/search.cfm?sw=viscometer&sort=p&sortDir=a

Hint: choose one that’s easy to clean up. Most aren’t, especially those made of curved glass.

[Gunther]

@RenKB yes the quantities in ( ) are net ASM

@Belassi the remaining water is topped off in ‘water qs to 100%’

[Gunther]

You can build one yourself:

1 Buy plastic graduated cylinders (IMO 50-100 ml work fine)

2 Drill a hole in the bottom. The hole diameter depends on the viscosity range you’re willing to test.
Even wikipedia ‘Flow cups’ article gives great info
https://en.wikipedia.org/wiki/Flow_cups

3 Get a stopwatch (even a smartphone app can work fine)

4 Fill it up with the bottom hole plugged.
Unplug and measure the time it takes to partially empty by gravity
   i.e. from 50 to 5 ml. You may want to paint the cylinder marks to make them easily readable.
don’t allow to fully empty as it ain’t accurate there.

You may wish to buy a bottle of your favorite commercial product with the proper viscosity you’re looking for, or get some liquid with a known viscosity as a “calibration standard”.