Homemade Foaming Handsoap - Part II

In a previous post, I revealed how astonishingly easy it is for me to be amused. By handsoap. No, I'm not Patrick, SpongeBob's brainless, starfish friend, but I have pursued my attempt at homemade foaming handsoap one step further.

My first recipe is as follows:
palm oil, 150 g
coconut oil, 50 g (both oils melted in a ca. 600 mL glass bottle)
water, icy cold, 240 g
potassium hydroxide, 90% w/w, 42 grams

I mixed the KOH with icy water (very exothermic and the icy water makes this part pretty non-smelly, resulting solution about 100-deg-F). Then I added it to a mixture of palm and coconut oils (melted and cooled to ca. 100-deg-F) and added some more water (ca. 100 mL) and shook the crap out of it. It was initially pretty lumpy and two phases. (I think I'd use an immersion blender next time.) For the next day, I shook this high tech glass mixing jar (old mayo jar, Hellman's) and let it set with the lid loosened (just in case the mixture got exothermic or something) and placed the entire jar inside a deep plastic bowl (just to contain anything unexpected). Within several days of leaving it alone, the resulting solution became homogeneous with a bunch of foam sitting on top.

So far, there's roughly 200 grams of solid soap in this mixture (roughly the amount of fat used). After some reading, foaming hand soap is mostly a result of the dispenser, but, equally important, it needs to be pretty dilute; somewhere between 4-10% solids by weight. If I shoot for a first guess of 5% solids (w/w), this would dictate taking this mixture and diluting it (ideally in deionized water) to a total weight of 4000 grams (roughly a gallon). I'm going to let it sit a while longer. After Easter, I'll dilute it and put it in bottles (I scored 5 of those pump bottles on ebay this morning for about a buck each, including shipping) and will let you know the results.

I'll probably also scent the mixture with lemon verbena essential oil if the soap foams nicely (not going to waste it until I know it works).

Parents of small children, you may be reading about the development of your xmas present.

Where to buy stuff:
1. Oils can be purchased here.
2. KOH can be purchased at the Science Co.
3. Hellman's Mayo can be purchased at Giant Eagle, but you have to eat 600 mL of it or dump it in the drain and use the bottle.

Part I
Part II
Part III

Homemade Foaming Handsoap - Part I (in an occasional series)

I don't think there's a more simple pleasure than foaming handsoap. Sounds silly, but compared to the drizzly liquid non-foaming soap, it's a party. And, when you have a young child, you realize washing your hands obsessively can be the difference between having a normal life and being sick for large chunks of a year at a time.

So, I've been cruising the net looking for why soaps foam and how to make my own and believe it or not, the only reasonable links I've found to attempt to make my own is from Cockeyed in this and this post! These links imply it's all in the dispenser, but I'm still hunting down the reason. If these Cockeyed expts. are valid, it's going to be amazingly inexpensive to refill a typical foaming handwash dispenser.

I'm still searching for why these work (if this is the case) and will keep you posted.

Also ...
Fun expt link for a foaming soap.

Ha!
Found what I needed:
Foaming Soap Patent, a calculator for concocting a liquid soap formulation, in the patent is a dilution factor and finally, all I need is a pump (or a recycled one that we already purchased) to make it foamy. It's actually the pump that makes the liquid soap foamy!

... to the lab.

Update
The potassium hydroxide's been ordered and the recipe formulated. Stay tuned for the recipe.

First attempt recipe: not done yet (3/28/07)
palm oil, 150 g
coconut oil, 50 g (both oils melted in a 2L plastic bottle)
water, icy cold, 240 g (and eventual dilution to 2.0 L)
potassium hydroxide, 90% w/w, 42 grams
lemon verbena scent, 10 mL (added after saponification)

Intended procedure:
-add KOH to icy water (very exothermic process, icy water keeps fumes minimal), let cool to ca. <100-deg-F
-melt oils in hot water bath in 2L soda bottle
-charge KOH/water solution to fats and wait until the resulting solution is homogeneous (saponification finished)
-add essential oil, dilute to 2L with distilled water, mix gently, done.
-refill dispensers with el cheapo liquid soap

Don't miss the breathtaking Part II in this series ...

Part I
Part II
Part III

Bubbles

Frankie and I explore various bubble formulations found on bubbles.org. In this one we investigate the bubbliness of using karo light syrup (less expensive) than glycerin. Formula = 150 g tap water + 15 grams ultra Dawn + 5 grams Karo. Then we blew through a 3/8" id tube to see how much it bubbled. Looked about the same as the forumla with glycerin instead of Karo.

Still need to try distilled water instead of tap (although most city water supplies are pretty soft). And here are some of the bubbles I scooped off the top and blew around the kitchen. A littel messy, but fun.