What is Trace in Soap Making?

By Ngscents @ngscents

What is trace? Baby, don’t blend me; don’t stir me, just pour. Trace is when you’ve reached emulsion- your oils are blended with your lye mixture and are no longer capable of separating. How can you tell when your mixture is at trace? The easiest way is to use your stirring utensil: hold it a few inches above your mixing container and move it back and forth. If the soap batter dripping off the stirring utensil leaves little lines that sit on top of the mixture in the bowl- that’s trace. It can be difficult to capture in photographs, but you’ll know it when you see it in motion.

So I reach trace and that’s it? Well, yes and no. There are different degrees of trace, but the important thing to remember is that once a mixture has reached trace- it’s only going to continue to solidify from there. Light trace is considered the bare minimum. Light trace is helpful when you’re looking to make swirls or other designs that require easily pourable, almost-liquid soap. Moderate trace is in the middle and means you’re ready to pour your soap into the mold. Heavy trace is when your soap gets thick. The picture above shows heavy trace. A soap batter at heavy trace is resistant to change shape and almost impossible to pour into a mold. Heavy trace may result in the need to scoop your soap into the mold, seen in the photo on the left. Not a pretty sight. Work quickly to ensure the soap does not set before you are ready.

What Causes Different Levels of Trace?

Trace can be affected both by your ingredients and your blending method.

Ingredients:

  • ‘Hard’ oils, including palm oil and coconut oil, and butters will reach trace much faster. Using softer oils such as olive oil or canola will decrease the speed of trace, but your end product soap will be much softer. Increasing the amount of oil to superfat your recipe will also slow down trace. (Be careful not to add too much or you’ll have an excess of unreacted oils.)
  • In addition, fragrance oils can accelerate trace. (Check out our CP Soap Testing results to see how our fragrance oils perform in the CP soaping process.)
  • Inversely, the more water you use, the slower your soap will reach trace. A water discount (using less water than the recipe called for) will accelerate trace and is recommended for only advanced soapers when they see fit.

Blending:

  • The speed at which you blend can accelerate trace. Using a stick blender as opposed to stirring manually with a spatula will increase the speed of the reaction and trace will be reached faster. If you suspect that the mixture will accelerate, stir it manually to slow the rate of trace.
  • Furthermore, the temperature at which you blend your ingredients will affect trace. Higher temperatures accelerate trace. If you wish to slow down trace, let your lye mixture cool down to about 100 degrees Fahrenheit before you add it to your oils.
  • The order also matters. If the fragrance oil you’re using is known to have a tendency to accelerate trace, be sure to add it last, after you’ve made your soap mixture and added any colorant, and be ready to move.

False Trace

All this talk about trace and the need to rush your soap process may have you running around like a chicken with its head cut off- but BEWARE FALSE TRACE. False trace usually occurs when oils in your mixture begin to cool down and solidify without going through emulsion or saponification. So, much like Goldilocks, you don’t want your mixture to be too hot or too cold, but juuuuust right.

Ahhh!

I know it seems like a lot- but if you pay attention to the factors listed here- you should be alright. Remember to have all of your ingredients ready before you start soaping (always, but especially) in case of any unexpected trace acceleration. You can do this, I promise. And if something goes wrong, you can always melt down your soap and try again. Thanks for reading and happy soaping!