Friday, February 25, 2011

An aside: Let's talk about drier feeling oils...

A few people have asked me about astringent oils lately, and the main question is "are they drying?"

Allow me to recap a post from last year with a bit more detail...

An astringent is actually defined as "chemical that tends to shrink or constrict body tissues, usually locally after topical medicinal application." By definition an astringent isn't necessarily a drying thing, but we do perceive moisturizing ingredients with astringent qualities as drying. These more astringent oils and butters still moisturize well, but they will give you the perception of being drier than regular oils.

Let's take something like mango butter, considered a dry or astringent butter. The tannins in the butter may make it feel astringent, and it may "shrink or constrict" your skin, but the fatty acids and phytosterols are still offering amazing moisturizing qualities, so you are still getting a nicely moisturizing creation!

If you take a look at non-oil based astringents, like alcohol or witch hazel, these can be drying because they don't contain all the lovely emollients we find in our esters, oils, and butters. (This is one of the reasons that cetyl alcohol isn't drying - it might be an alcohol by chemical definition, but it's a fatty alcohol, so it has that fatty or emollient part on it, which overcomes the drying possibilities of the alcohol part!) Witch hazel is less astringent and drying than alcohol, and can actually offer some moisturizing features for oily skin (click on the post to learn more).

Let's say you want to use an astringent butter or oil on dry hair or skin, will it still moisturize? Of course it will, because it contains all those lovely fatty acids. If you use an ester on dry hair or skin, will it still moisturize? Yep, because it's still an emollient. The chemistry of our drier feeling or astringent oils and butters means it feels drier but it will still behave as an emollient moisturizer that will do all the great things the non-astringent feeling butters, oils, and esters!


Will said...

Weird idea for a topic. Your post on "minimally processed" made us think of this.

Things that color (with benefit).

I recently found that a (very) small amount of sea buckthorn seed oil colors a lotion an attractive light yellow like Clinique's product. Feels great, too! I just wish it wasn't $10 for 1/3 oz.

What other oils or extracts will attractively color a lotion?

Is there anything that would result in a light purple? At first I was thinking something based upon grapes, but those seem to be brown.

Sadly, most flower infusions seem to favor brown, too.

Anything that might result in pale pink, light blue, orange, or pale green?

I know there are color additives, but I was thinking something that might have inherent skin benefits, too. Non-staining is probably important too (said while remembering experiment with carrot oil).

Christina said...

Thank you for this post! I was just wondering about what the heck can be meant by a "dry" oil, if even the dry oils have all those lovely fatty acids & other moisturizing things. Your post explains it very well.

I discovered your blog several weeks ago and have been slowly reading through all your past posts. I really enjoy reading all about the different things you make, and I love you positive attitude towards chemistry. I also think chemistry is very fun! I miss my college classes.

I am planning to make my own body products, starting with shampoo and conditioner and then later body wash, shave lotion, face soap, makeup remover, body lotion, and, uh, a lot more! Anyways, I'm finding your blog very useful as I research ingredients and find out which ones I should spend money on (BMTS, yes! Seabuckthorn oil, maybe not! Preservative, yes!).

Since I like "natural" and "unprocessed" things, I probably would have been one of those people who didn't use a preservative if I hadn't read your blog. So, thank you for that alone! Now I get so mad when I see recipes elsewhere on the internet that use GSE or Vitamin E as a "preservative." There is so much misinformation in the world, so thank you for fighting against it as well as you can!

You'll probably see me continue to bumble around here as I get my recipes refined. Thanks!

Meaue said...

Wow - this shows how much I have learned over the past year - that was me asking.... Sometimes us newer formulators need to leave the normal vocabulary mindset. Alcohols (cetyl) aren't "bad" (in fact I love them!) in formulations like [still learning] people may think - and I'm sure you can add to the list, eh, Susan? I totally trust you and if you had something horribly scary sounding in your recipe, I'd still try it, because I know you'd never put in something that did not "bring something to the table". Thanks for the blast from the past!

p said...

Great post! I've had a question about just this topic for a while now....

It's so bizarre and counter-intuitive to me that it's not the fatty acids that make an oil feel dry or greasy, but rather the "extras" like tannins (I didn't know that until I started reading your blog!). Which has me wondering: if I use only greasy-feeling oils in a lotion and add a tannin-rich ingredient like green tea extract, will my lotion feel dry despite the greasy-feeling oils? It seems like it should, but I haven't noticed you describing this effect (maybe I've just missed it, though!). Would adding tannin-rich water soluble ingredients be a reasonable way to decrease the greasiness of a product, similar to how you use IPM?

Susan Barclay-Nichols said...

Hi Will. I've never tried colouring lotions as I like the white or creamy colours of mine. I do like sea buckthorn for the buttery yellow colour, and I have found that grapeseed extract is that browny colour (which is really unpleasant, although it went the colour of blood in my cleanser when I mixed it with rosemary extract! Creepy!) Sorry I can't be more helpful here.

Hi p. Great question! Yes, you can add tannin rich extracts to products to make them feel less greasy, but I've found that the 0.5% suggested usage amount won't make that much of a difference. I have tried using green tea butter - I think it was coconut oil with green tea extract, and a lot of it! - and it definitely made my product feel drier. But we shouldn't really go over 0.5% of these extracts, and they don't seem to make a big difference there.

Welcome, Christina! Chemistry is great fun, and not the boring topic they made it seem in school!

Hi Meaue! Isn't it cool when you have some kind of marker to show you've what you learned? When I look back at the first posts of this blog, I'm so tempted to alter them like silly to represent what I know now, but I won't do that - I have to keep them intact! It's so cool!

p said...

Good to know, Susan! I wonder if this is because the quantity of tannins in 0.5% green tea extract isn't that much compared to the amount of tannins (or other astringents) that make 10% mango butter feel so different from 10% shea butter.

Will - thought I'd add my two cents about colorants. I've used alkanet root to color oils a super rich red-purple. Annatto seed colors oils orange, yellow upon dilution. You could use these oils to make a pink, orange, or yellow lotion. In my experience, neither alkanet oil nor annatto oil stains the skin (like, say, beets do), though if you use a ton of colorant and the oil remains on the surface of the skin, you would see some color. Also, I would guess that you could infuse oils with chlorophyll-rich ingredients to get green as well.