Wednesday, December 29, 2010

Experiments the workshop: Using disodium cocoamphodiacetate & decyl glucoside

Sorry, I didn't get around to formulating with the emu oil as I've been running around testing everything with my pH meter, and got into the surfactants bin in the workshop! I'll have some posts on emu oil shortly!  My husband has started calling me "magpie" because I'm easily distracted by shiny things! 

Now that I have my fancy new pH meter, I can finally do some formulating with disodium cocoamphodiacetate (pH 9 according to the data sheet, but mine tested at 7.7) and decyl glucoside (pH between 7 and 9, I forgot to test it). I thought I'd throw a little polyglucose/lactylate blend into the mix because it does feel really nice and moisturizing on my skin!

I decided to make my usual body wash but switch the disodium cocoamphodiacetate for the cocamidopropyl betaine, and the decyl glucoside and polyglucose/lactylate blend for the other surfactants. I've kept every other ingredient the same - including my usual fragrance, lemon curd - so I could see what each ingredient brings to the mix. I accidentally added 1% more than I wanted of the decyl glucoside and I only had 30 grams of polyglucose/lactylate blend left, hence the amounts I used in this recipe. Next time I'll make the body wash with esters - which is my new favourite recipes - with just the disodium cocoamphodiacetate in place of the cocoamidopropyl betaine.

EXPERIMENTAL BODY WASH RECIPE
10% disodium cocoamphodiacetate
21% decyl glucoside
10% polyglucose/lactylate blend
10% aloe vera
10% chamomile hydrosol
28.5% water
4% glycerin
3% polyquat 7
2% hydrolyzed oat protein
2% panthenol
0.5% liquid Germall Plus
1% fragrance oil

I mixed it all together, then tested the pH - 8.6! That's way too high! So I mixed up 0.2% citric acid with a titch of warm water to dissolve and added it to the mixture. New measurement - 7.74. Still too high. We want 6.5 or lower. So another 0.2% citric acid with a titch of water and added to the body wash. Success - we have 6.51!

As a note, it seems like 0.2% citric acid will take the mixture down about 1 pH level (give or take), so if you make this recipe and don't have a meter, 0.4% will bring the levels down to a reasonable level. The main ingredients that mess with the pH are the decyl glucoside and disodium cocoamphodiacetate as the polyglucose/lactylate blend has a pH of 5 to 7. So if you use the first two surfactants and use any surfactant with a pH between 5 and 7 as your third surfactant, then the 0.4% should bring the pH down enough. 

What's the viscosity like? It's thin. Very very thin. I could put this in a foamer bottle and not have to thin it out at all! Normally the Lemon Curd fragrance oil thickens it quite well, so I need to add a little Crothix. I added 1%. Not enough, so I added another 0.5%. Still not enough, so I added another 0.5% for a total of 2%. It's still on the thinnish side and could use a little bit more, but I don't like to go over 2% because it's so easy to turn it into Jell-O, so let's leave it there.

How does it feel? It feels really nice. I think thanks in part to the polyglucose/lactylate blend, but I did find it to feel very moisturizing. It foamed and lathered very nicely, and I think this would be a great product for someone with normal to oily skin. If I were to make it for my dry skinned friends, I'd increase the polyglucose/lactylate blend to 20% and reduce the water amount by 10%.

FINAL RECIPE FOR EXPERIMENTAL BODY WASH
10% disodium cocoamphodiacetate
21% decyl glucoside
10% polyglucose/lactylate blend
10% aloe vera
10% chamomile hydrosol
28.1% water**
4% glycerin
3% polyquat 7
2% hydrolyzed oat protein
2% panthenol
0.5% liquid Germall Plus
1% fragrance oil
0.4% citric acid

**Save about 5% of your water to dissolve the citric acid.
Add Crothix or salt as necessary to increase viscosity. I used 2% and it wasn't really thick enough!

As a note, I think this would make a fine 2-in-1 body wash and shampoo for those inclined as it has all the goodies you'd put in a shampoo!

As a note, I coloured it pink despite its lemony deliciousness so I would know that it wasn't my usual body wash because the labels tend to fall off in the shower and I don't make anything else that's pink!

8 comments:

Tara said...

I am excited to do this recipe since I actually have all of the ingredients! I also have a pH meter, but unlike you I have barely used it. I better get to it.
Thanks Susan!

Jenny said...

Thanks so much for this post! I've been holding off using my Decyl Glucoside because no recipes include citric acid amounts and because my test strips don't seem to work with it (they don't change) but your post has inspired me to try it out. Do you think that a body wash or shampoo would be mild enough with Decyl Glucoside as the only surfactant as long as the PH ends up in the 5-6.5 range? Also, some of your recipes clearly call for the heat and hold method (like your 3-in 1 body wash on 11/26) but this one sounds like it's just a mix and you're done recipe. Am I correct that this one doesn't need heat and if so, why the difference? Finally, have you ever made a kitchen cleaner using Decyl Glucoside as the primary ingredient (I've seen many of these in natural food stores)? Thanks again!

Susan Barclay-Nichols said...

I would normally heat and hold but I was eager to make my product yesterday morning so I could post about it today, so I admit...I didn't heat the ingredients. I did use distilled water, but I used proteins, and it's not a good idea to use proteins without heating and holding. Bad, Swift, bad! When I make this again, I will heat my surfactants and water phase to 70˚C then take it out of the double boiler and wait for it to cool before adding the cool down ingredients. I was just in a rush yesterday!

I wouldn't use just decyl glucoside as the only surfactant - it would be very mild, and it would take a lot to bring down the pH. Adding a second surfactant like cocamidopropyl betaine will increase the mildness and viscosity dramatically, and you'd get some better sudsing and lather out of it. It'd also bring down the pH a bit!

As for making household cleansers, sure, why not? I wouldn't use decyl glucoside because it's not an inexpensive surfactant - I think it's the most expensive one I own - and I like using castille soap for that purpose.

Aesthete said...

Great post, would this recipe be suitable as a face cleanser too?

Susan Barclay-Nichols said...

Hi Aesthete! I think it would work as a facial cleanser for certain skin types - my very oily skin might find it too moisturizing!

Michelle said...

Hey Susan,

Despite you not heating and holding as usual, the next time you made this awesome concoction, did you add the 0.4 % Citric acid dissolved in 5% Distilled water in the Cool Down or earlier?

Ryan Pusztai said...

Do you have to heat & hold when using surfactants Cocomidopropyl Betaine & Decyl Polyglucose like in this recipe?

My recipe did not thicken up correctly as well & has a slimy snot feeling to it haha. I didn't have all ingredients so used the following:

20% Cocomidopropyl Betaine
21% Decyl Polyglucose
20% Aloe Vera
28.1% water
4% glycerin
2% Panthenol
0.5% liquid Germall Plus
1% EOs
0.4% Citric Acid

Any help on this would be greatly appreciated!

Susan Barclay-Nichols said...

Hi Ryan! I'm glad you are enthusiastic, but you really don't need to flood me with your requests for help. One message, one comment - that is generally more than enough.