Is stearic acid the same as stearine?

[SunRiseArts]

Saw stearine in the craft store at the candle section. Almost got it, but figure I ask first?:mrgreen:

 

[Kittish]

Short answer, no, it's not the same. Stearin is derived from stearic acid, though.

Huh. From Wikipedia:

It is used as a hardening agent[8] in the manufacture of candles and soap. In the manufacture of soap, stearin is mixed with a sodium hydroxide solution in water. The following reaction gives glycerin and sodium stearate, the main ingredient in most soap:

C3H5(C18H35O2)3 + 3 NaOH → C3H5(OH)3 + 3 C18H35COONa
Stearin is also used in conjunction with aluminium flakes to help in the grinding process in making dark aluminium powder.

https://en.wikipedia.org/wiki/Stearin

So it looks like you could use it in making soap, so long as the stuff for sale doesn't have any other ingredients that aren't soap friendly.

 

[DeeAnna]

It's vice versa -- stearic acid, a fatty acid, can be made from stearin, a fat.

***

But the OP asked about "stearine" with an "E" on the end. The word "stearine" with an "E" may indeed be a synonym for stearic acid, not stearin, but the similarity to "stearin" without the "E" is confusing. I'd be real careful to confirm which chemical that you've got before assuming you have one or the other.

***

Tallow, lard, palm and other fats can be separated fairly easily into "stearin" and "olein" by cooling the melted fat slowly until some it solidifies. The solid part of the fat -- the stearin -- is filtered out of the liquid part of the fat -- the olein. Like any other triglyceride fat, stearin (or olein) creates glycerin when it is saponified.

Stearic acid is made by further processing the stearin to break the fat molecules apart into glycerin and fatty acid molecules. The glycerin is removed and the fatty acids that remain are either sold as commercial grade stearic acid, which is a mix of mostly stearic and palmitic acids, or further purified. Stearic acid adds no glycerin when it saponifies.

Stearin will saponify slowly just like any normal soaping fat, while stearic acid saponifies very quickly, just like any a fatty acid.

 

[SunRiseArts]

Thanks. I just saw it on the candle section. Does not list ingredients, just says stearine.
I think Irish lass mentioned it, so I checked it out when I went to hobby lobby.

Since I was not sure, I did not get it.

 

[DeeAnna]

If it's being sold for candle making, my guess is the "stearine" you found is stearic acid. Stearin (without the E) is not a modern-day ingredient for candles.