Is this what glycerin rivers look like? (and expecting DOS)

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Elise

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I almost forgot that I actually registered here to ask this question.
I made small batches of soap to test if I could feel anything different with different additives. As these were about testing additives I wanted a cheap recipe. I ended up using 75% canola oil 😅, I don't know why, I did read about canola oil and DOS quite a lot but only remembered after I made them. So I guess I can expect DOS growing on these soaps. I guess that will be an opportunity to witness it. But it has been almost 3 months and still nothing. I'm almost looking forward to see it 😂

But that is not what I want to ask your help with. On my oat soaps there are two spots with a very different color. It looks a bit translucent and was softer than the rest of the soap. What do you think it is ? All soaps have the same base recipe (75% canola oil and 25% coconut oil) and only this one has those spots. Could the oat flour be responsible for that ? The other additives I was testing were liquid : goat milk, coconut milk, soy milk.
I made oat flour soaps again since (but better choice of oils ;) ) and haven't seen anything like that in them.

IMG_20230911_104002.jpg IMG_20230911_104807.jpg
 
It’s pretty quiet here and I wish I had a brilliant answer for you, but I haven’t seen anything quite like those spots before. They seem to be aligned vertically along the centerline of the soap, which to me suggests that they are not due to the oats or the way the batter was mixed. The only thing I can come up with is a “glycerine river” type effect due to heating in the mold. What lye concentration did you use?
 
It’s pretty quiet here and I wish I had a brilliant answer for you, but I haven’t seen anything quite like those spots before. They seem to be aligned vertically along the centerline of the soap, which to me suggests that they are not due to the oats or the way the batter was mixed. The only thing I can come up with is a “glycerine river” type effect due to heating in the mold. What lye concentration did you use?
My water to lye concentration was 26,643% (water as % of oil = 38% ; water/lye ratio 2.7534:1)
Yes - I agree. It does look like a glycerin river in texture, but it's weird how it's just in blobs like that. A glycerine river would usually be in a 'river' or a crackle.
I know... I mean, I've not seen glycerin rivers yet but this doesn't look like the pictures I've seen online. However I couldn't figure something else when researching an other explanation.
 
I agree that those are probably glycerin rivers. That is a LOT of water to use for a CP soap; you might consider changing from 38% water-as-percent-of-oils to a 33% lye concentration. Less water will help with preventing future glycerin rivers, and the bonus is that you can unmold sooner, too :)
 
You may not see DOS with canola oil. I have made shampoo bars with a high percentage of canola oil for years and never see it. To be honest I don’t know why!
 
@AliOop @AliensrReal Yes, I didn't modify this setting in soap calc for my first batches. Now I definitely reduce the amount of water. Especially since I usually use a lot of liquid oils. I did 36% and then 34% water. I'll try 33% for my next batch. It is indeed enjoyable to get bars of soap you can handle without denting the next day.

You may not see DOS with canola oil. I have made shampoo bars with a high percentage of canola oil for years and never see it. To be honest I don’t know why!
I will see... Part of the reason why I'm okay with having these soaps hanging around is that I've read many conflicting things regarding canola oil and DOS. Also I don't know if canola oil we have in grocery stores in France is the same as in the US (I never quite understood the difference between canola and rapeseed... they all translate the same in french). So, first hand experience is probably best to get a better understanding of this oil.
 
What do you find is the benefit of going by lye concentration over water as % of oil ? I never thought about that.
 
@Elise When you switch from "water as percent of oils" to "lye concentration" (or water:lye ratio, which is the same thing, expressed a different way), the amount of lye doesn't change for that recipe, but the amount of water usually does.

Using lye concentration will give you a more consistent amount of water for each batch, especially if you scale up or down, raise or lower the super fat, etc. With lye concentration, you no longer have to mess around with "water discounts" - simply change the lye concentration. Higher lye concentration = less water, and vice versa.

The default setting in most calculators is water at 38% of oils, which is typically a decent amount of water for hot process soap, where a lot of water evaporates during the cook. But it is way too much for most CP recipes; 33% lye concentration is almost always a more reasonable amount of water for a CP soap batch. (That being said, I use 40% lye concentration myself, because I'm not usually making complicated designs, and I want to reduce ash and unmold sooner).

Of course, some folks love that default setting and are happy working with it. My theory is that's only because that's what they've always used, and change is difficult. The analogy is how those in the US and UK prefer the wonky imperial system of measurement, rather than the infinitely more sensible metric system. We are all used to it, and the initial change would be very hard (and expensive).

I remember when there was a big push for changing to metric when I was in grade school. I sure wish they'd done it then so we were past all that and happily using it now!
 
What do you find is the benefit of going by lye concentration over water as % of oil ? I never thought about that.

Turns out it's more useful to the chemistry of saponification if you base the amount of water on the amount of alkali (lye) in the recipe. If you control the water based on alkali, you'll get more consistent results with various types of recipes. You can directly relate changes in how the soap batter behaves to the amount of water in the recipe IF the water is based on the alkali.

"Water as % of oils" is based on the amount of fat in the recipe. The math involved with "water as % of oils" changes the amount of water in proportion to the alkali in unexpected ways. "Water as % of oils" will call for you to use MORE water in proportion to alkali for recipes that would do better with LESS water. And vice versa. The end result is you have to tweak the "water as % of oils" setting for ~every~ recipe to get the results you want and the way you have to tweak this setting for each recipe is arbitrary -- it doesn't necessarily make a lot of sense.

Water:lye ratio or lye concentration are the two settings that base the water on the alkali (lye). Both measurements are mathematically exactly the same, so pick whichever one makes more sense to you and stick with it.

My advice is to use about 33% lye concentration (2:1 water:lye ratio) for most recipes. That works pretty well for most recipes a lot of the time. If you want to do something other than 33% lye concentration (2:1 water:lye ratio), then you can tweak the setting in a controlled and understandable way.

More in my article: Lye conc vs water:lye ratio | Soapy Stuff
 
Thanks a lot @AliOop. I will have to read that a couple more times to really get my head around this 🤭 But I find it really helpfull.

Edit : and thank you @DeeAnna, just saw that you answered as well. I'll read your article.
 
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