my first batch. what did i do wrong?

[pgringo]

i made my first batch of bar soap last night from biodiesel glycerin. today i checked it and it has the consistency of silly putty. any ideas of what i might have done wrong?

the recipe i used:

10 fl oz glycerin
6.25 fl oz water
6.25 g lye

 

[carebear]

because we haven't a clue what your "glycerin" is comprised of we cannot begin to tell you. we work with oils of a known SAP and thus know how much lye to use. with your materials it's anyone's guess...

btw: when we (as in B&B makers as opposed to biodiesel folk) talk about glycerin we are referring to purified glycerin. biodiesel "glycerin" is a mix of free fatty acids, and glycerine plus whatever stuff is left in the mix from the waste material and any solvents that were not completely removed.

 

[mandolyn]

Have you tried posting to one of the biodiesel soapmaking forums? I'm not trying to chace you away, but I don't know if anyone here can help you. Try googling biodiesel soapmaking. Here's a search result:
http://www.biodieselnow.com/forums/p/18723/137339.aspx

 

[pgringo]

so if a bar soap is gooey, does that mean it "needs" more lye in the process in order to make bars that are more firm?

i'm trying to learn here and i really really appreciate y'all's feedback.

 

[mandolyn]

so if a bar soap is gooey, does that mean it "needs" more lye in the process in order to make bars that are more firm?

i'm trying to learn here and i really really appreciate y'all's feedback.

Not necessarily It could mean there was too much water, or that there weren't enough of the right type of oils to firm up the bar. Here again, we go back to oil qualities & SAP values & the difference in cold process soapmaking & making soap from biodiesel byproduct. There's a world of difference & I'm pretty sure very few similarities other than lye & water.

First of all, you need to know which form of lye to use - sodium hydroxide or potassium hydroxide. You determine that by which one was used in the biodiesel process. Whichever was used to produce the biodiesel is the one you have to use. Some biodiesel byproduct will only yield liquid soap, because it's a result of biodiesel produced with potassium hydroxide.

Again, I don't make soap from biodiesel, & only know this info from the little research I've done.

I strongly encourage you to do your own research. I don't claim to have any answers to your problem.

 

[pgringo]

the biodiesel was made with sodium hydroxide, and the soap was also made with sodium hydroxide. i've been reading all night tonight and finding out a few things. please correct me if i'm wrong...

thin room temp oils make gooey bar soap.
thick room temp oils make hard bar soap.


the waste vegetable oil the biodiesel was made from was nice and thin oil with no hydrogenation so it makes gooey bar soap? yes?

so if i want to make firm bar soap i need to add vegetable shortening or coconut oil to the recipe?

t.i.a.
-philip

 

[carebear]

the biodiesel was made with sodium hydroxide, and the soap was also made with sodium hydroxide. i've been reading all night tonight and finding out a few things. please correct me if i'm wrong...

thin room temp oils make gooey bar soap.
thick room temp oils make hard bar soap.


the waste vegetable oil the biodiesel was made from was nice and thin oil with no hydrogenation so it makes gooey bar soap? yes?

so if i want to make firm bar soap i need to add vegetable shortening or coconut oil to the recipe?

t.i.a.
-philip

That's not necessarily the case - for example olive oil results in a very hard bar.

I suggest you read through some soapmaking resources - two that come to mind are soapcalc.com (read especially the parts about the fatty acid profiles and what they contribute to soap) and millersoap.com.

The problem is that because your biodiesel glycerin is a by-product we don't actually know what fatty acids are present.

All in all, I"d say soaping with biodiesel is a crap shoot. Through trial and error you will probably find a reasonable amount of lye to use for that batch of "glycerin", but when you get a new batch of waste material it'll be different and you will need to figure it out again.

Good luck.

 

[Soapmaker Man]

There is at least 2 web sites I know of where the owners make and sell soap from glycerin left over from the biodiesel process. :? I agree with CareBear. I personally find this to be a guessing game. I can refer you to their sites though....

 

[carebear]

is there a cost-effective means of analyzing each batch of "glycerin" for it's fatty acid profile?

 

[mandolyn]

What about this?

http://www.biodiesel-kits-online.com/bi ... -soap.html
http://www.utahbiodieselsupply.com/books.php

I'm sure it would be of more help than I can be.

Good luck with this by the way.