How to prevent Glycerin Rivers
In short, here’s what I gathered from multiple sites:
(Please note, these are just notes that I’ve gathered to help myself and hopefully others. I like keeping my notes all in one spot! ;))
1. Use less water (AuntieClaras uses 1.4 water:1 lye ratio, as opposed to a “full” water amount)
2. Soap at low temperatures (SoapQueen suggests working at 10 degrees less, others suggests working at room temperature)
3. Mix colorants, powder, and clays well (use a mini mixer to fully blend into oils. For example, WholeSaleSuppliersPlus explains that some soapers “…put a small amount of their oils into plastic beakers or disposable mixing cups. They then add the pigment (titanium dioxide) to the oil and mix well…They then add the liquid pigment to their soap batch prior to fragrance”.)
4. Don’t use too much colorant (especially titanium dioxide), powders, clays. (Follow retailers recommended amounts)
5. Make sure the environment is not too hot and insulation is not too thick (Perhaps you should remove the insulating towel but leave your mold in a box? Or try not to induce heat all together if you know your recipe will heat it up enough. Also, check your mold! Try silicone instead of wood.)
6. Avoid gel phase (Put mold in freezer)
7. Reconsider your spicy or floral fragrances and sugary liquids such as milks, that can cause heat. Or, just be aware of these wonderful, but possibly-troublesome ingredients, and follow the tips above.
9. Many soapers in forums I’ve read swear there’s a link between Palm oil and glycerin rivers (Some suggested keeping palm content less than %40, some suggested keeping the palm oil warm rather as opposed to room temperature).
10. Removing oils that tend to heat up. (GreatCakesSoapWorks informed readers that rice bran oil made her recipes heat up and crackle.)
I’ll keep adding to the list as I find more info.
Helpful links on glycerin rivers: ModernSoapmaking