7 Tips to Control Trace in Cold Process Soap Making

While I originally conceived of this article as a resource for soapy friends having issues with their soap batter accelerating, Control Trace in Cold Process Soap it really is a guide for all soap makers to help understand what goes into the soaps, and how to manipulate trace. Because, sometimes you want that soap to trace faster than it is!

Cold process soap batter can be finicky, especially when you’re new to the process of making soap or if you’re using ingredients (like fragrance oils and certain essential oils) that effect “trace”. As it turns out, there are ways to control the trace of your cold process soap batter to help make the most of your time and your ingredients.

I’ve put together 7 tips to help you understand and control your trace, and I hope that you’ll add your own tips to the comments below so we can all help other soapy friends as they run into issues with their formulations.

1) Understand the “trace” in cold process soap.

In soapmaking, trace is a the term soap makers use to refer to the point when the oils and water are past emulsification and are starting to thicken up. Understanding trace will help you manipulate your formulations and processes to avoid failed soaps.

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There are different types of trace, all of which reflect the consistence of the soap batter:

• Emulsion: This means your oils and liquid are emulsified… that’s when two unlike substances are combined in a homogenous solution, and they stay suspended (they don’t break apart). When a soapmakers says the batter is just at emulsion it means the suspension is stable but you don’t see any visual trace. You can mold your soap now, and the oils and water will not separate.
• Light or thin trace: A trace happens when you drizzle some of the batter onto the top of the batter and you can see a “trace” of where it was. A light trace means you may see a light light mark of where the drips or drizzles were, but it doesn’t stay. Light trace reminds me a bowl of heavy whipping cream before you whip sugar into it to make whipped cream. Light trace is perfect for fancy intricate swirls.
• Medium trace: If you keep blending (or allow the soap to sit, or add heat) you’ll hit medium trace. You will for sure see drizzles left on the top of the batter. Medium trace reminds me of cake batter, and it’s perfect for suspending additives (like poppy seeds) into your soap batter.
• Thick trace: Keep blending (or add more heat, or just wait for time to do the work for you) and you’ll hit thick trace. With a thick trace, your batter looks like a thick pudding, and you can make great textured tops.
• Soap on a stick: while not a “trace” soapmakers are looking for, it’s worth mentioning here, because it’s what most soapmakers are looking to avoid! Soap on a stick is when you’ve gone past thick trace (possibly due to an accelerant) and literally have soap on a stick. The batter is so thick that you cannot remove your stick blender or spatula from the batter!
• Finally, there’s false trace: When you think you have trace (because the batter has thickened) but oils and liquids are not yet emulsified, you have false trace. With false trace your oils will start to seep out of the batter resulting in an oily residue on your soap.

This video includes visual examples of various stages of trace in soap batter:

2) Know your ingredients because they can accelerate or hinder soap trace

The first thing we need to discuss is your ingredients. Not what I use, not what your other soapy friends use, but what ingredients you’re using in your soap. Why? Because some ingredients can cause havoc on your formula… not that you can’t use them, but more that you need to understand them so you can adjust your processes and formulation accordingly.

Here are a few examples:

• Colorants: look at what you’re using to color your soap. Are their any known issues with your colorant of choice? One great example is fermented indigo, which can (well, it DOES) accelerate trace.
• Scents: Another culprit is fragrance. Many essential oils (and quite a few fragrance oils, so I’m told) can create soap on a stick in moments.
• Base Oils: Some oils, such as coconut, simply trace faster. Why? Because of chemistry! The saponification process produces heat, and some oils (like coconut) create a higher exothermic reaction. More heat = faster trace. So, watch the coconut oil. On the flip side, slower moving oils (like olive oil) will not come to trace as quickly.
• Liquids: If you’ve seen me soaping before, you know I love my 1:1 water:lye solution. I like to keep my liquids low! Controlling trace is one reason why. If you have a high amount of liquids in your formula, you’ll reach thicker traces faster.
• Sugar: This includes anything with sugar in it: honey, milks, fruits, maple syrup, and even beer. Sugar will accelerate trace the same way coconut oil does… by increasing the heat of your batter.

3) Understanding temperature to control trace in cold process soap

I admit it, when I first started making soap I really thought that everything had to be at specific temperatures. Namely that the oils and lye solution both had to be at 102F at the same time. I probably read it in an old soapmaking book. It was probably true for that exact recipe and design, but not for all recipes. In fact, the “perfect temperature” for your cold process soap recipe is going to be unique to, well, to your recipe.

Here’s the basics you need to know so you can manipulate your temps:

• Saponification is an exothermic reaction. That means it makes heat. If you want soap, you need heat. Or rather, you will generate heat. And, the more heat you have, the faster the saponification process will complete.
• Lowering the temperatures of your batter (both the oils and the lye solution) will slow the saponification process down, and thus slow down trace. This will give you more time for intricate swirls, etc.
• Contrary, raising the heat of your batter will speed up the saponification process. This could be a boon if your goal is to get a nice thick trace for textured tops.

Now, keep in mind that “adding heat” doesn’t always mean an external heat source (like a burner or crock pot). You can also add heat by adding various ingredients, such as sugars as mentioned above. You can also “add heat” by continuing to blend with your stick blender…

4) Know when NOT to use the stick blender

A stick blender is a soapers best friend… but it can also be your worst frenemy! My number one tip here is to try, just once, to make soap without your stick blender. It doesn’t have to be a successful light trace, but get to an emulsion. Heck, use all coconut oil since it moves fast. The key is to experience for yourself that you don’t need the stick blender all the time. It’s a tool, and some soap makers over use it.

Here’s when I don’t use a stick blender:
First, I 99% of the time, start with the stick blender, at least to emulsion. Then, I put it down and don’t pick it back up if…

• I’m working at hotter temps. No need for friction (which is added heat) if my batter is already hot.
• I’m working with fast moving oils. Again, no need for heat causing friction when the ingredients add the heat for me.
• I want to work slow, for whatever reason, so I put the stick blender aside.

5) Lower the water content, and control trace in cold process soap

First off, I’m expecting some push back on this point for sure. For years I thought I needed to add more water to my formulations because I simply could not get any of those fancy swirly designs to work. And, everywhere (i.e. all the pages on the internet) I read that lower water is going to accelerate trace.

And then, by total accident, I found out that it’s not true (for me).

The accident was (I think) when I was running low on distilled water. True to soaping spirit, I made soap anyway! And you know what? The same recipe that never gave me pretty swirls worked like a charm. Then the experiments started…

I made soap with all sorts of varying water amounts. And time after time, the more water I added, the faster I reached trace. Ever since, water content is my #1 factor to manipulate a formula for trace.

If I want to trace faster, I add water. Slower? yup, reduce the water. In fact, it’s why I soap at 1:1 water:lye and then add in extra liquid stuff when needed for color or whatnot. I just have to keep in mind that the more water I have, the faster trace will happen.

Now, if you have a higher amount of hard fats and butters, it’s possible water could slow things down for you. Maybe it slows down saponification with palm oils? I’ve never used palm oil, while most soapers do. So, that’ my best guess as to why everyone says more water = slower trace (but it doesn’t).

The big take away: run some water test and time your trace with various amounts. See for yourself (and then report back to me, please!)

6) Reduce or avoid accelerants

If you’re experiencing soap on a stick with every attempt at adding clove essential oil to your soap… well, you might have to give in and not use it! This is just one additive that is known to accelerate trace. Cinnamon does it too, as well as many fragrance oils. But, as I said above in the “ingredients” section, you have to to completely remove them from your recipe, but rather, understand them and the limits to which you can push adding them to your soap.

7) Consider softer or slower moving oils

If you’re aiming for a specific formulation to use for intricate swirly designs, consider slower moving oils. Typically soft oils (like olive oil, sunflower seed oil, etc.) are slow moving oils. While hard oils (like coconut and butters) are faster moving. Reducing the amount of coconut oil in your recipe could give you more time to play with swirls, if that’s what you’re aiming for.

A quick guide for controlling accelerating soap batter.

I admit, it was hard breaking all of that up into different categories. Why? Because they all go hand in hand! I think this shorter summary might be useful to illustrate what I mean and give you some insights to how you can control trace in cold process soap making:

If you want your soap to move slower try one or two of the following:

• Reduce added heat / starting temperatures
• Reduce total water content
• Reduce or remove accelerants
• Use softer oils
• Put down the stick blender

If your soap takes forever to come to a trace, and you want to get things moving along try one or two of these:

• Add heat / start with warmer oils
• Add more liquid to your formula
• Add known accelerants
• Use harder oils
• Stick blend away (but try not to burn out your stick blended!)

How do you control trace in cold process soap?

If you have a tip, or want to comment on mine, use the comment form below. I want to hear how you control trace in your cold process soap!

And, because so soapy post is complete without some fun soaps, here are a few “failed because of trace” soaps that were shared over in my Facebook group. Each one was a fantastic save too!

Though it doesn’t look like a fail, I “saved” this batch in the middle of pouring. The EO blend I used thickened up my soap in seconds. It was supposed to be a wood grain pour and that requires a very fluid (thin trace) pour. So I had to think fast – I continued pouring the medium traced colors in horizontal lines (this was in a slab mold).

I used a wood skewer to make horizontal lines at a slight angle (zig zag pattern) – this created a type of rough wood grain you see in cedar planks. Fortunately I had colors that were perfect for cedar wood.

The soap was set up enough within a few minutes I could draw some thin, random lines across the slab to create texture. Then I added “knots” with tiny flattened balls of brown soap. I pushed them down slightly below the soap in the mold and used the skewer to draw a spiral line in the “knot.” Desperation is truly the mother of invention- I think the soap came out looking more like cedar wood than if I had done a successful wood grain pour. 

This is my accelerated batter/imo fail soap.

My plan was to do a high up drop swirl but the top started to seize in the bowl. It was a “glop it on and throw a spatula through it and hope for the best” swirl. Others think it was done purposefully but nope.

Green: Nettle infused olive oil with 1 Tbsp nettle powder at light trace

Cream: Dandelion blossom infused olive oil

I’m fairly certain it was the EO blend I used which was Rosemary : Marjoram : Peppermint at a 3:2:1

I have already posted my biggest failure here but have to repost it  If there were a competition for the ugliest soap this could be the winner.
 A soap called ‘shitty pants’ 
This was supposed to be a pumpkin cinnamon soap, orange with a brown swirl but I probably over blended and the EO I used did its thing.
It turned out yellow and ‘muddy’ in the middle 
So I tried to save the day, found a plastic mat and tapped it in with a little hammer.
Believe it or not, I sold all of them.