Monday, July 31, 2017

Question from Patreon: How to use alcohol in a lotion? (part one)

On my Patreon feed page, Albert asked: If I wanted to make an after shave balm which includes some alcohol in it, my questions are: 
1. In which of the 3 phases (water, oil, cool down) should I add it?
2. In terms or ratios, does the alcohol count as part of the water or the oil content?
3. How much maximum % of alcohol of the total balm can/should one add?

In the same thread, Charlette asked: If alcohol is in an ingredient list--is there no rule of thumb as to where to add it?  (Similar to, let's say for example-- almond oil-- which we KNOW gets added in an oil phase). It seems to me that common sense would have it added in cool down (because would it not evaporate if in a heated water phase?  Or  would it mesh with oil in a heated phase?).  I've seen a few ingredients listing alcohol--so my curiosity is also peaked.

The quick answer to the first question is this: Alcohol is water soluble and can sort of handle heat, so it goes into the heated water phase. If you are using small amounts, say 5%, you can add it in the cool down phase, if you prefer.

Related post: How do you know when to add an ingredient?

The second one is simple: Alcohol comes out of the water amount. When we add an ingredient, generally we remove part of the water amount. So let's say we have 80% distilled water in a recipe and we want to add 10% alcohol, we would remove 10% from the distilled water amount, making it 70%. We do this so we always have a recipe that totals 100%.

Related posts: Adding and removing from the water amount

The third one...well, that one has had me searching my textbooks and on-line for more time than I'd care to imagine. I can't find anything reliable about how to use our normal emulsifiers - including Polawax, Incroquat BTMS-50, Simulsol 165, and so on - with ethanol. I did find that Natragem EW, a natural version of Polawax, is stable at 2% alcohol, which gives you an idea that we can't just add it to the product willy nilly.

I've been experimenting with using 10% vodka in a lotion using stearic acid-TEA as the emulsifier, and not only is it lovely and stable, it feels nice on my skin. The only down side I see is that this has an alkaline pH of over 8, which isn't great for a leave on product as our skin has a pH of 4.7 to 5.5-ish. If you're interested in trying this at home, substitute 10% of the distilled water or any hydrosol with 10% alcohol in this duplication of Lush's Dream Cream.

Join me as we take a look tomorrow at using alcohols in gels and lotions!

4 comments:

Kirsten Thomas. said...

I am following this with morbid curiosity. I have to admit that I am still shaking my head like a dog with water in it's ear, trying to wrap my head around why they added vodka or other alcohol to these products. I have been working for the last few years making my skin care with no alcohol at all, and very little witch hazel (just the toner) because my skin is so dry. What do you see as the primary reasoning behind the vodka? I know Lush does lots of funny ingredients (mashing things up in water, etc.). So I am really quite captivated. Good reading, Swift!! thanks

Heather Barnes-Bursey said...

I'm also intrigued and curious as to why anyone would want alcohol in a lotion. For that classic aftershave sting? Will stay tuned...

KMY said...

Am also following this thread. I too want to make a lotion with alcohol -- I have a Px topical pain cream that is too heavy, so need to reformulate it. Since I can't source the medicine part I will use it as part of my own blend. In general this cream has alcohol, lidocaine, and heavy oils. I also dissolve some meds in alcohol for the same use, since I can't ingest anti-inflammatories. I hope this helps others to understand why we might NEED alcohol in a formula.

Susan Barclay-Nichols said...

Thank for sharing, KMY! (I have my reasons, too, as I've been working with active ingredients that don't dissolve well in water.)