Stearic Streaks or Soda Ash?

[dblbubble]

I'm not sure if what I have is stearic streaks/spots or deep soda ash. I KNOW it's not lye, as I did the "zap" test...just soap.

My recipe is on the Soap Calc pic, and I soaped at 103° for the oils and 113° for the lye water. I don't get this on my smaller, 3 lb. batches; this was for a 5 lb. batch.

This is driving me nuts!

Any thoughts?

 

[kchaystack]

If it is ash it will wipe off with a damp paper towel.

 

[jcandleattic]

Looks like ash to me. If it was stearic spots IME it would be throughout the soap and not just on the top/sides but where the cuts were made as well.

 

[Kittish]

Looks like ash. And I love that wood grain imprint on the soap.

 

[dblbubble]

It's pretty much throughout the soap, on top and into the soap itself. In the past, this didn't wash off, so that's why I thought it was stearic.

I'm stumped because I went with a 34% lye concentration (water discount) that works great for my smaller batches. Why would it do this for a larger batch? Temperature?

 

[jcandleattic]

Still looks like ash to me. Stearic spots are usually just that, spots, or dots really throughout the inside of the soap soap not just on the edges.

Ash is caused by several things, recipe, water %, temperature of the soap, whether it gelled or not, humidity, ambient temperature of the room, etc., etc.

 

[toxikon]

I was curious about this, so I did some digging... here are some interesting blog posts.

http://www.kimridgefarm.com/-soap/soap-making-guide/soda-ash-is-not-soda-ash.html

http://www.soap-making-essentials.c...f-soap-using-the-shea-butter-soap-recipe.html

https://www.soapqueen.com/bath-and-...nd-tricks/explaining-and-preventing-soda-ash/

 

[Kittish]

The recrystallized soap explanation makes sense, and would go a long way toward explaining why 'ash' can occur even inside soaps. If it was CO2 + lye, actual soda ash, then it should only happen on faces exposed to air (or mean you'd got lots of bubbles in your soap). Also would explain why spraying the top of freshly poured soap then covering can help prevent it. Alcohol would form a vapor barrier between the water present in the air and the surface of the soap.

 

[IrishLass]

My Scientific Soapmaking book by Dr. Dunn has a section on what we often term as soda ash. Sometimes it really can be soda ash (sodium carbonate), but at other times it can be one of a few of other different things, such as sodium hydroxide, or soap crystals that have precipitated out from the main body of soap, or some other water-soluble substance. Here is a link to his presentation called 'The Secret Life of Soap' where he examines the subject of soda ash, complete with pics of soap with white stuff on it that he tested to determine what the white stuff was actually made up of (some was soda ash, some wasn't): http://cavemanchemistry.com/HsmgJojoba2011.pdf


If it doesn't wash off with water it's not soda ash. Also- if it doesn't dissolve in ethanol, it most likely is not soda ash.


IrishLass

 

[dblbubble]

Now I'm beginning to wonder if it IS sodium hydroxide???!!!

I grabbed a piece and did a solid "zap" test on the white spots...I held my tongue there for a couple of seconds and definitely felt a tingling/stinging. When I held my tongue on the clear/solid areas, nothing.

I tried to wash it off in the sink - nope, won't wash off. And even did the vinegar test - no bubbling so not soda ash.

So my question is, if this IS sodium hydroxide, how did this happen? I followed the Soap Calc recipe to the "T" and made sure all the lye crystals were dissolved. I soaped at 34% lye concentration, which has worked fine for me before.

I'm so confused! I live in Virginia and I know Dr. Dunn is about 2 hrs. away from me...I wonder if soapers go to him for advice/consulting?

BTW, if this makes any difference, I only unmolded the soap and cut it yesterday. I made it on Tuesday and so I guess it's still saponifying.

 

[dblbubble]

Yep, I'm pretty sure this batch is lye heavy after seeing this link; it looks just like mine:

http://www.newenglandsoaps.com/lye-heavy-soaps/

Guess I could start looking into how to make this into laundry soap. What I really need is some pH strips to be sure.

 

[Kittish]

If the lighter spots are lye heavy, could it be that you didn't mix this batch enough before putting it in the mold? Also, how long has it been since you made the soap? If it's only been a day or two, I'd test it again in a few days and see if it's still stingy. Though I wouldn't do so by putting my tongue directly on a bar. Wet a suspect area with water, rub it a bit with a gloved finger, touch the finger to your tongue.

 

[jcandleattic]

What I really need is some pH strips to be sure.

pH strips are notoriously inaccurate for soap. I wouldn't trust them.

 

[earlene]

First, really really, please do not stick your tongue onto the outside of your soap like the kid in A Christmas Story!

[ame]https://www.youtube.com/watch?v=_RgCbcT8eEU[/ame]

Serious damage can occur. This is NOT the safe way to do a zap test. Please read the sticky post How To Properly/Safely Conduct The Zap/Tongue Test.