The science of ash

[Bubbles Galore]

Re: The dreaded ash problem

U made and interesting point Bubbles, about the higher superfating and using 20% water discount made with goats milk. I may have to try this if I don’t want the ashy look on some of my bars, it sort of looks earthy though. I got a kick out of honor435 saying “embrace the ash! I think it looks cool,”
When you discount the water 20%, do you make that up with the goats milk, or do u substitute the water altogether with the goats milk? Can I buy goats milk in the market? (I have not goats) ..never used it..but would regular milk work?
Jerry S

I only meant that it's not the palm oil on it's own causing ash. :wink: Now other goat milk soaps I made in the past had heaps of ash. If I have to pin point anything that might help, it's the gelling in the oven but I don't know if that will always be the case for every recipe. Certainly, spritzing with alcohol helps.

Water discount: I make the soap with full goat's milk and just discount the 20% off. You can use full cream cow's milk for a lovely bar too. :wink:

 

[soapopera]

Re: The dreaded ash problem

I only meant that it's not the palm oil on it's own causing ash.

Thanks for contributing your input. I'm still new at this and still experimenting. It just happened that the only batches I'd made with ash had Palm oil in it :? . Anyway, I tried again last night, another Palm recipe but using a higher percentage of superfat and higher lye concentration. It's a smaller batch though. We'll see how it behaves. I'm also wondering if the figures of fatty acids in it matters. Like maybe those fatty acids that have not been saponified (superfatted) reacted or not reacted with air. Soapbuddy mentioned beeswax will help. When I click on Beeswax in SoapCalc, I'd noticed it does not have any fatty acid. Could this also means like maybe the beeswax kinda 'protected' those fatty acids that would react to air? me and my imagination

 

[dubnica]

In my experience, alcohol sometimes does not work. I had a batch of small animal soaps that I sprayed a lot and I still got thick layer of ash. This particular batch had Crisco in it and I think the most ash I get is on soaps where I use high % of shortening. I hate ash.

 

[soapopera]

Update: Yeap the pesky lil ashy surface again on my 3rd batch with palm. I made another batch with no palm in same type of mold, also left uncovered. The other one is spotless, except for a few cat hair landed on it

I was thinking, could be the fatty acid Palmitic? My batches that doesn't have ash has a very low Palmitic value. I went through SoapCalc briefly and look at some Palmitic values I saw:

Palm: 44
Crisco (with palm): 20
Rice Bran: 22
Avocado butter: 21

 

[bombus]

I used to cut the ash off of the top of the bars when it did occur, but then I
lost texture, and sometimes cut the top off of an air bubble that I didn't know
was there.

Lately, I have been using 91% isopropyl alcohol from Walgreens. I spray it on the
soap after it is in the mold, cover the whole thing tightly (tape down the edges)
with clear wrap & then put it in the 100 degree oven. After gel, I leave it covered
for up to 2 days (I think this is superstition). My log mold is made so I can open
a side and slide out the lining and soap and re-use the mold while the soap is "resting".

My ash problems have pretty much disappeared, and the surface of the soap
is usually shiny. I have noticed when I bevel the edges, that the top surface
is a little darker in color than the soap right underneath. That must be caused
by the alcohol. I have noticed that it seems to speed up saponification on
the surface and cause a skin to form. (don't bother "touching up" a swirl once
you have sprayed) that may be the cause of the color change.

When I do get ash now, it is usually late in the cure. I take the bars to the sink
with an old toothbrush and a spray bottle of vinegar. I hold the bar in a vertical
position and spray the top with the vinegar. Then I gently brush the ashed parts,
rinse with more vinegar, and let the bar air-dry standing on a rack. This often removes
the ash, and leaves the bar with a shiny top. Any ash on the sides or bottom
I trim away.