Glycerine Rivers

[EllieMae]

I just unmolded my second batch in a row that is full of glycerine rivers. I’m hoping (as a total newbie) that I can get some advice on how to best avoid in the future, when I want a full gel.

Both batches were soaped around 120 (admittedly the first one was closer to 130). Should I be consistently soaping at 110 or less (my earlier readings suggested this would prevent full gel)?

I set up both on a heating pad on medium for 30 and left under insulated boxes for 24+ hours. Is this step always needed for full gel or only when soaping at lower temps?

Essential oils I used were jasmine and cinnamon for one (I’ve since read cinnamon can cause lumpy batter, but I wonder if it also affects rivers?) and tea tree for the second. i haven’t been able to find a listing or suggestion of what oils can encourage rivers more than others. Both batches were also pigmented which definitely made the rivers more pronounced.

Any ideas of what I can try for the next batch would be great! I’m using more or less the same recipe for these batches to try to keep something consistent while I figure this out!

 

[ShenandoahEarth&Botanical]

What lye concentration or lye:water ratio are you using? Using full water (in addition to the heat you mentioned) can lead to glycerin rivers, so you may want to try a water discount.

 

[EllieMae]

What lye concentration or lye:water ratio are you using? Using full water (in addition to the heat you mentioned) can lead to glycerin rivers, so you may want to try a water discount.

That’s a good question. I haven’t fiddled with lye ratio or water discount from the base on SoapCalc (which I think goes by water as percent of oil at 38%?).

To be honest...I wasn’t sure when or how to work with that to create a water discount. I keep reading that water discount of 10% may help but have yet to figure out how to work that into the calculator. I’m off to read more! Thanks!!

 

[DeeAnna]

I suspect you're using "38% water as % of oils" probably. I wish the soap recipe calcs didn't use that as a default -- it creates more problems than it solves.

Switch to using lye concentration or water:lye ratio and reduce the water content, as Shenandoah suggests. I normally suggest setting the lye concentration to 33% (water:lye ratio of 2:1) to reduce the chance of "rivers". See what you think. More: https://classicbells.com/soap/waterRatioConc.asp and https://classicbells.com/soap/waterInSoap.asp

"...I set up both on a heating pad on medium for 30 and left under insulated boxes for 24+ hours. Is this step always needed for full gel or only when soaping at lower temps?..."

What a person needs to do to encourage soap to gel will depend on a lot of factors. I never heat the soap in the mold and seldom insulate it. My starting batter temperature is often around 95-105F. My soap often (not always) gels. But there are so many other factors involved that it's hard to give definite rules about what to do or not to do. Room air temp, soaping style, size of mold, type of mold (loaf versus slab), water content, etc.

 

[user 29721]

What pigment(s) did you use? Titanium Dioxide is prone to cause glycerin rivers and it surely does in every single batch I make!

 

[EllieMae]

Switch to using lye concentration or water:lye ratio and reduce the water content, as Shenandoah suggests. I normally suggest setting the lye concentration to 33% (water:lye ratio of 2:1) to reduce the chance of "rivers". See what you think. More: https://classicbells.com/soap/waterRatioConc.asp and https://classicbells.com/soap/waterInSoap.asp

Thank you, thank you, thank you! I’ve been so hesitant to switch from the 38% of oil setting because I had no idea what to use as a general starting point. I will also try a batch without heating or insulating. See how that works out!

What pigment(s) did you use? Titanium Dioxide is prone to cause glycerin rivers and it surely does in every single batch I make!

One batch had some titanium dioxide (and then yellow mica and light lavender mica) and the other was black. Black didn’t show as badly but still had just as many rivers.

 

[KiwiMoose]

Glycerin rivers are beautiful
If you've got it - flaunt it!

 

[SideDoorSoaps]

I love the look of rivers as well. I seem to get them most often when I use micas. My regular soap recipe has a water discount of 40% and my soaps usually gel. It’s interesting to see the separation and I never seem to get the rivers when I’m trying for them! I agree with Kiwi! Flaunt them!

 

[DeeAnna]

I like 'em too!

 

[KiwiMoose]

I pretty much get rivers in all my soap, unless I don’t gel it. It’s more noticeable when I use TD.

 

[DeeAnna]

I think soap often creates "rivers" but the patterns are usually small and not noticeable. Titanium dioxide (TD) really does seem to make them more obvious.

 

[SideDoorSoaps]

I think soap often creates "rivers" but the patterns are usually small and not noticeable. Titanium dioxide (TD) really does seem to make them more obvious.

Do you think maybe there could be a displacement of the colorant if it’s not really mixed in well? Most of my mica colorants have TD in it. I rarely use it by itself and when I do, I mix it into my lye water but not the colors.

 

[user 29721]

I don't think mixing has to do much with it, it is most likely the presence of TD in the batter that catalyses the glycerin rivers. You can find micas without TD - oxides are one of them. Embrace the rivers, gel with the micas without TD, skip gel or do a steep water discount are the ways to get around it. I like the look of rivers myself! We should do the challenge around it!!!

 

[DeeAnna]

It's not really about inadequate mixing, although it is about displacement of the colorant. "Rivers" are created because different types of soap molecules crystallize (freeze) at different temperatures and this differential crystallization is creating those odd swirly patterns.

Have you ever put a can of soda pop with sugar in the freezer and left it too long and it froze? If you have, you'll know the sugar syrup in the soda stays liquid at freezer temperatures, but some of the water in the soda will freeze and make lacy ice crystals mixed with the non-frozen syrup.

Now would you agree with me that the soda started out very well mixed? But now, after freezing, the soda has separated into a solid phase (the ice) and a liquid phase (the syrup). Both of these phases are quite different in composition.

If you look at the ice closely, you'll see it is water clear. If you could taste just the ice, it will also taste pretty much like water. Nearly all of the sugar, color, and flavor is concentrated in the remaining liquid.

This is differential crystallization at work.

The titanium dioxide in soap is like the colorant and sugar in the soda pop. Some soap will crystallize at a higher temp -- that soap is like the water ice. As this soap crystallizes (freezes), the TD particles migrate into the soap that's still liquid. When that lower-melt-temp soap finally crystallizes, the TD remains trapped in those portions of soap.

 

[dibbles]

I don't think mixing has to do much with it, it is most likely the presence of TD in the batter that catalyses the glycerin rivers. You can find micas without TD - oxides are one of them. Embrace the rivers, gel with the micas without TD, skip gel or do a steep water discount are the ways to get around it. I like the look of rivers myself! We should do the challenge around it!!!

Amy Warden did a challenge featuring glycerin rivers a few months ago. Scroll down to see all of the entries.
https://soapchallengeclub.com/glycerin-river-designs-winners-announcement/

 

[SideDoorSoaps]

Excellent explanation, @DeeAnna! Thank you so much! I just recently started using micas and TD so the appearance of rivers for me is a new phenomena.

@EllieMae did you take pics? I’d love to see!

 

[lenarenee]

Glycerin rivers are beautiful
If you've got it - flaunt it!

Love them too! Rarely get them. Guess I'll have to do a ghost swirl soap!

 

[Martha]

Amy Warden did a challenge featuring glycerin rivers a few months ago. Scroll down to see all of the entries.
https://soapchallengeclub.com/glycerin-river-designs-winners-announcement/

You just sent me down an amazing rabbit hole looking at all the soap challenges. So inspiring.

 

[dibbles]

You just sent me down an amazing rabbit hole looking at all the soap challenges. So inspiring.

There is some amazing creativity out there. It's fun to see!

 

[Zing]

What @DeeAnna said. The only time I got rivers was using TD. Now when I use TD (and I look carefully at colorants that include it), I soap at lower temps and use a lye concentration to 33% and have successfully avoided rivers. We're usually harder on ourselves than others, though -- people wanted to know how I got that ''look" in my soap. Soaping is a lesson in surprises and letting go of perfection, for me, anyway. Now when soap turns out differently than expected, I call it 'rustic.'