Wood ash lye soap

Soapmaking Forum - Soap & Candle Forums

Help Support Soapmaking Forum - Soap & Candle Forums:

Hertzyscowicz

Member
Joined
Aug 16, 2008
Messages
14
Reaction score
0
Location
Tampere, Finland
For the past couple of days I've tried as many batches of wood ash lye soap. I mentioned this in my introduction post, and MikeInPdx at least wanted to be kept posted on that. So, here's my experiences so far, with batches made in a half-gallon pot:

The method I've used for making wood ash lye so far has been to mix water and wood ash at about 1:1 ratio with the ash uncompressed and to boil it for about fifteen minutes. This yielded lye that at least turned my liquid pH indicator dark purple. I've had success using simple household paper towels to filter the ashes out. Poorly filtered wood ash lye may result in ash residue in the soap, which kind of defeats the purpose.

The two tries I had with liquid oils, rapeseed and olive, have been somewhat unsuccesful. I'm pretty sure neither of the oils even saponified. In the case of Olive oil it may be because I added baking soda during the boiling, to mimic the Sodium carbonate that's found in the Marseille soap's mix. Unfortunately, baking soda is sodium bicarbonate which neutralizes NaOH. I was hoping it would degrade in the heat to form sodium carbonate. It might have turned out different if I had boiled it in a separate kettle.

I have had more success with solid oils, namely beef tallow and coconut butter. The batch I made with beef tallow stank to high heaven and the excessive dose of peppermint oil only made matters worse.

I just poured the coconut batch to cool down and precipitate, so I can't tell how successful it was. What I can tell, though, is that mint leaves double as a nice dye when added during the boildown phase of HP. Also, dithering with household vinegar revealed that the .8-litre batch of wood ash lye only had about 5 grams of NaOH.

Sorry about not posting pictures, I'll see if I can find a camera later.
 

mandolyn

Well-Known Member
Joined
Feb 4, 2008
Messages
1,198
Reaction score
7
Location
Nebraska
My first question is, are you using a soap recipe that you know works with regular lye? From what I'm reading, your making single-oil soaps which isn't always successful even with regular lye. You can make soap, but some single-oil soaps never get hard.

I'd say find a recipe of mixed oils, run it through a lye calculator so you know how much lye you need, then proceed with your experimenting. I think you'll get better results.

Have you made CP soap with regular lye before? If not, that's where I'd start before trying to produce lye. If you have, just ignore this part. :D
 

Hertzyscowicz

Member
Joined
Aug 16, 2008
Messages
14
Reaction score
0
Location
Tampere, Finland
I haven't made any CP soap, unless you count high school chemistry (in which case rapeseed oil was used). I might have a shot at CP if I find the time. If I recall correctly, lye was prohibitively expensive in the apotheracy, though.
 

mandolyn

Well-Known Member
Joined
Feb 4, 2008
Messages
1,198
Reaction score
7
Location
Nebraska
Hertzyscowicz said:
I haven't made any CP soap, unless you count high school chemistry (in which case rapeseed oil was used). I might have a shot at CP if I find the time. If I recall correctly, lye was prohibitively expensive in the apotheracy, though.
Ok, you can pursue making your own soap this way, but I really think you're going to have a tough time of it.

Sodium hydroxide is not expensive. You can buy it on-line from a soapmaker supplier for just a few dollars. One container makes several 2 lb batches of soap. If you're in the US, you can buy Roebic drain cleaner from Lowes which is 100% lye for just a few dollars. Beware! Not all drain cleaners are 100% lye, some contain metal shavings & junk that's harmful to you.

I think if you understand the importance of having the precise measurement of lye, you'll be more successful at this attempt. Lye is extremely caustic, so you don't want to burn your skin off with lye-heavy soap!

Here's a site that will be helpful:
http://www.tlcsoaps.com/soapinst.htm

It takes about an hour to produce a good batch of soap. Time well spent towards continuing your potash experiment.

You need to know the SAP values of the oils you're using to know how much lye to use. We all use lye calculators for that. You can find good into & a lye calculator here:
soapcalc.com

SAP values will also help you get a hard bar of soap instead of a mooooshy, soft bar.

Well, if you have more questions, we're here for you. I probably gave you waaaaaaaaaay more info than you wanted!


:lol:
 

booner

Member
Joined
Mar 5, 2008
Messages
17
Reaction score
0
I've done a bit of research on the topic but I don't have the resources to try making soap this way yet so I'll pass along a couple things I was going to try.

The first and most important being using a hydrometer to measure the specific gravity for the lye water. You can get these at brewing supply stores. Be aware, different hydrometers are calibrated for different solutions so a brewing hydrometer might very well sink straight to the bottom of a lye solution.

Also salting your soap during the boil will create a hard bar... But it will also remove the glycerin.
 

mandolyn

Well-Known Member
Joined
Feb 4, 2008
Messages
1,198
Reaction score
7
Location
Nebraska
booner said:
I've done a bit of research on the topic but I don't have the resources to try making soap this way yet so I'll pass along a couple things I was going to try.

The first and most important being using a hydrometer to measure the specific gravity for the lye water. You can get these at brewing supply stores. Be aware, different hydrometers are calibrated for different solutions so a brewing hydrometer might very well sink straight to the bottom of a lye solution.

Also salting your soap during the boil will create a hard bar... But it will also remove the glycerin.
OK. I'm absolutely clueless about why you want to use a hydrometer. A digital scale that measures to the tenth or hundredths works just fine, & is what we soapmakers use. Salting isn't necessary to get a hard bar of soap. That's where knowing SAP values & using lye caclulators like at soapcalc.com are for.

The right combinations of oils will yield a rock-hard bar of soap without the use of salt.
 

Deda

Well-Known Member
Joined
Apr 21, 2008
Messages
3,269
Reaction score
44
The hydrometer would measure the specific gravity of the lye/water solution. From that you can calculate the percentage of lye. Right?

So what I think you are saying is that if you pour water over ashes to make lye water you would have no idea how much lye is in the water? If you calculate the density, or specific gravity, difference between plain water and the lye/water mix you would be able to tell what your water/lye ratio is? More precisely than the floating egg?

I know my scenario is wildly simplified, but am I following you?

Using sodium hydroxide is super easy, but part of the reason I make soap is, well, because - I can make it myself. Like knitting a sweater instead of buying one. I am intrigued with the idea of making lye, or at least being able to make lye.
 

mandolyn

Well-Known Member
Joined
Feb 4, 2008
Messages
1,198
Reaction score
7
Location
Nebraska
Deda said:
The hydrometer would measure the specific gravity of the lye/water solution. From that you can calculate the percentage of lye. Right?

So what I think you are saying is that if you pour water over ashes to make lye water you would have no idea how much lye is in the water? If you calculate the density, or specific gravity, difference between plain water and the lye/water mix you would be able to tell what your water/lye ratio is? More precisely than the floating egg?

I know my scenario is wildly simplified, but am I following you?

Using sodium hydroxide is super easy, but part of the reason I make soap is, well, because - I can make it myself. Like knitting a sweater instead of buying one. I am intrigued with the idea of making lye, or at least being able to make lye.
Thanks for the explanation. Makes sense now.
 

booner

Member
Joined
Mar 5, 2008
Messages
17
Reaction score
0
Deda said:
The hydrometer would measure the specific gravity of the lye/water solution. From that you can calculate the percentage of lye. Right?

So what I think you are saying is that if you pour water over ashes to make lye water you would have no idea how much lye is in the water? If you calculate the density, or specific gravity, difference between plain water and the lye/water mix you would be able to tell what your water/lye ratio is? More precisely than the floating egg?

I know my scenario is wildly simplified, but am I following you?

Using sodium hydroxide is super easy, but part of the reason I make soap is, well, because - I can make it myself. Like knitting a sweater instead of buying one. I am intrigued with the idea of making lye, or at least being able to make lye.
Right on the money. Once you determine a desirable specific gravity for your lye solution you'll be on your way to having a dependable recipe. Of course, once you introduce new oils into the mix, you'll have to experiment all over again.

And as far as salting for a hard bar. Keep in mind we're talking about Potasium Hydroxide (or depending on who you talk to, Potasium Carbonate). Either way, it's not Sodium Hydroxide so the final product tends to be softer, and depending on the oils used, may not saponify at all.
 

carebear

Well-Known Member
Joined
Oct 18, 2007
Messages
7,714
Reaction score
71
that is, of course, assuming there is nothing else of substance in the solution. I'm leery, but wth - the pioneers managed (tho they seem to have scooped their soap out of containers rather than get solid bars from a lot of what I've read)
 
Top