soap overheated (w/pics)

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JLem

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Well, this is a first for me. A few minutes after I poured this newly made soap into the mold, it began to crack and then "erupt". Clearly, it overheated, but I can't figure out why exactly. My process is the same as it normally is...except I needed to reformulate the base oils since I was out of palm oil, which I usually use at ~20%. So, I increased the olive and coconut oils and added a little beeswax. I'll provide the recipe below.

I have two questions:
1) any idea what may have caused the overheating? Is the formulation ok?
2) will the soap still be usable?

1,000 g batch
Olive oil - 40%
Coconut oil - 35%
Sunflower oil - 10%
Walnut oil - 5%
Castor oil - 5%
Palm oil - 3%
Beeswax - 2%

Lye concentration = 30.5%
Water as % of oils = 33.28%
Super fat = 3%

Added - 1 tbsp clay (Fuller's Earth) to lye solution
Added - 3 tsp essential oils at trace (1 tsp each of cedarwood, pine, and orange EOs)

I didn't measure the oil or lye temperatures...but I never do, and this has never happened before. Adding beeswax is new for me...but at only 2% I wouldn't have thought it would make this happen...but could that be it?
 

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What temperature were the oils/lye when you combined them? I hope the high melting point of the beeswax didn't seduce you to raise temperatures too much?
 
When you change the recipe, did you run it through a lye calculator again? I had a soap go super nova on me once when I grabbed the wrong lye solution; it got so hot that I put it is a bag and then tossed it into the middle of the driveway and then grabbed a fire extinguisher.
 
What temperature were the oils/lye when you combined them? I hope the high melting point of the beeswax didn't seduce you to raise temperatures too much?
I didn't measure the temps...I never have...just wait a bit for the lye solution to cool down some...had worked up to this point

When you change the recipe, did you run it through a lye calculator again? I had a soap go super nova on me once when I grabbed the wrong lye solution; it got so hot that I put it is a bag and then tossed it into the middle of the driveway and then grabbed a fire extinguisher.

Yes...I ran it through SoapCalc online. I knew that changing the oils potentially/probably changed the lye.

35% CO and the beeswax and the high water amount is what caused the over-heating. Not sure about the EO's but possibly the orange may have contributed.
Yes, it should be usable; just make sure to do a zap test.
Thanks. I increased the water to account for the beeswax...I was afraid of it tracing too quickly. I usually run my recipes at 33% lye (~30% water as percent of oil). My normal "base recipe" is usually 30% olive oil, 30% coconut oil, and 20% palm oil, with the other 20% being spread between various other oils. I guess I just didn't wait long enough for the lye temp to cool down enough. Glad to know that this should be usable.
 
It sounds to me like you have figured out the cause of overheating, so I'll chime in on a few other things.

Rather than using water as percent of oils, if you stick with lye concentration, that will keep your batches more consistent as you scale up and down, and as you wish to increase or decrease the amount of water.

Hopefully you used EOCalc.com to determine safe usage rates for each separate EO? I'd also encourage you to measure them in grams, not by teaspoons (or any other volume measurement). This will also give you much greater consistency as it is possible to over-fill or under-fill a teaspoon by significant amounts, which can be dangerous if your specific EO has a low safe-usage rate.
 
It sounds to me like you have figured out the cause of overheating, so I'll chime in on a few other things.

Rather than using water as percent of oils, if you stick with lye concentration, that will keep your batches more consistent as you scale up and down, and as you wish to increase or decrease the amount of water.

Hopefully you used EOCalc.com to determine safe usage rates for each separate EO? I'd also encourage you to measure them in grams, not by teaspoons (or any other volume measurement). This will also give you much greater consistency as it is possible to over-fill or under-fill a teaspoon by significant amounts, which can be dangerous if your specific EO has a low safe-usage rate.

Yes, I use lye concentration for my recipe formulations. Usually I stick to 33%, but this time I reduced it to 30.5% because of the potential the beeswax had for speeding things up. I use SoapCalc for all my recipes, so just included the value for water as % of oils since SoapCalc gives it and I figured some folks may be more familiar with this value.

Thanks for the EOCalc.com...I was unaware of it and will take a look. I measure all my oils, water, and lye using a gram scale, but with EOs I find it simpler to just use a teaspoon. One teaspoon is approximately 5ml, which for an EO comes out to between 4-5g. My scale doesn't have the precision to weigh out tenths of grams, so the teaspoon does the trick...even if I slightly over or underfill it, I will be off by less than a gram one way or the other. I think 4-5 grams in a 1,000g recipe is probably within the safe usage rates of all the EOs I use...probably on the low end actually.
 
Just chiming in, I have never found that adding water helps in any way. In my opinion it always makes things worse. Extra water means the soap gets hot quicker and stays hot longer. I usually use a 35% - 40% lye concentration, way less problems with a stronger lye solution. No overheating, glycerin rivers or soda ash.
 
Just chiming in, I have never found that adding water helps in any way. In my opinion it always makes things worse. Extra water means the soap gets hot quicker and stays hot longer. I usually use a 35% - 40% lye concentration, way less problems with a stronger lye solution. No overheating, glycerin rivers or soda ash.
Good to know. Thanks. Luckily, things seem to have worked out ok. I cut the soap this evening and it all looks good.
 
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