Grainy, mealy, uneven body butters are the bane of any formulator’s existence. You’re dreaming of something silky smooth and divine, but instead your body butter feels like its full of sand… or perhaps you were promised a solid bar, but got oily slop instead. Bleh! Let’s learn how to solve all that 😄
Want to watch this project instead of read it?
Very generally speaking, we can describe the problem as “uneven consistency”. This can manifest in quite a few ways.
- Your butter or balm might be grainy, with hard little beads distributed throughout a softer buttery/oily body.
- It might be mealy and feel like it’s full of fine-grain grit.
- It might have an extra hard top and a too-soft, gooey under-layer.
- It might not’ve set up at all, and you’ve got a gloppy mess instead of the firm balm you were hoping for (this can also be because the formulation isn’t suited for your ambient temperature and it’s just too hot for it to set up, so you’ll have to do some troubleshooting there).
- It might suffer from some combination of the above problems, too. That’s fun!
But basically: if your body butter feels uneven on the skin, didn’t set up at all (not that it’s too soft, but it’s completely liquid when it was supposed to be solid), and/or is softer in some parts and harder in others, that’s the problem we’re learning how to solve in this post.
Why does this happen?
The butters we use in cosmetic formulation are made up of a variety of different fatty acids like stearic acid, lauric acid, oleic acid, and palmitic acid. Each one will go from solid to liquid at different temperatures. If you let them, the solid, saturated ones will solidify before the unsaturated, liquid ones, resulting in hard grainy bits throughout a product that is otherwise softer than desired.
The solution, broadly
To prevent graininess and uneven hardening, anhydrous butters and balms need to be cooled properly. What’s “properly”? Well… it depends.
Broadly speaking, “properly” means cooling the butter in a way where the entire butter cools at the same rate; even cooling = even texture. Precisely what “proper” cooling looks like can vary quite a lot from formulation to formulation, though (yay).
Grainy butters are like a race, where a few fatty acids sprint ahead a win. Smooth butters are team work, where everyone sticks together and crosses the finish line at the same time.
It’s also important to remember that all the work of proper cooling can be ruined if the product melts or softens too much throughout its life: this can be anything from a lip balm that spends a lot of time in a pocket, a body butter left near a heating vent, or a balm left in a hot car. The flip-side of this is that you can usually fix a grainy body butter by gently re-melting it and cooling it again.
This is a strategy I learned in my Formula Botanica Diploma in Organic Skincare Formulation coursework back in 2018, and have practiced and refined ever since. It’s a game changer!
Autumn 2023: If you'd like to try out Formula Botanica for free, they're offering a no-cost formulation masterclass where you can learn even more about formulation + test out their teaching style! You can sign up here 🙂 I highly recommend it ❤️
The general idea is this: you stir the melted, liquid formulation until it cools and thickens enough to leave a trace of itself on the surface of the mixture when you drizzle a bit of it back on itself. That’s where the name comes from 😄 If you are a soap maker you’ll be familiar with this. Once you’ve reached the desired level of trace you pour the formulation into its tin, jar, tube, mould, etc.
There are different degrees of trace, though no hard definitions around what constitutes light/thin, medium, or heavy/thick. I generally think of light trace as being barely discernible—the faintest whisper of a trace. So thin you’re not sure it’s happened; this one takes practice to get a feel for. Medium trace is obvious, but not fully three dimensional. Heavy trace is getting to the “oh no, I’m not going to be able to pour this” stage and is fully 3D. After that we hit “ack, too far!” where the product has solidified before you’ve poured it. Whoops! (No worries—you can gently re-melt and try again.)
The thicker the trace is the more challenging it will be to pour, and the more likely you are to have bubbles in your finished product. Thicker traces + intricate moulds = bad combo.
In order to achieve trace without pulling your hair out, you’ll want to consider how quickly your formulation will thicken/solidify. With that in mind, try to set things up so your formulation cools quickly enough that you don’t die of boredom and your stirring arm doesn’t fall off, but slowly enough that things remain smooth (and you can keep up).
If your formulation has lots of wax it’ll thicken much faster than a formulation that is only solidified by butters. If it’s a small batch, it’ll cool faster than a big batch. If you’re using a thick glass measuring cup, that’ll cool more slowly than if you’re using a thin beaker, plastic, or metal.
Big batch + thick glass + no waxes? That’s going to cool pretty slowly, so I’d use an ice bath to speed things along.
Small batch + thick glass + some fatty hardeners? I might choose a cold water bath instead of an ice bath so things don’t move too quickly.
Lots of wax? I’d probably just stir it on the countertop so I can keep up (though formulations with lots of wax are generally less likely to go grainy as the wax sets up so fast the butters don’t have as much time to dawdle and form lumpy fatty acid cliques).
Generally speaking, I prefer to work with thick glass when I’ll be tracing a formulation as I really like how thick glass slows down cooling. It’s much easier to speed things up than slow things down. I’ve tried metal and plastic and they cool so quickly that it is downright stressful (and often requires a re-melt and re-try in thick glass).
I’ll usually choose an ice bath as the speeding-up tool, and I’ll move the measuring cup in and out of the ice bath to keep things moving at a comfortable rate. If I notice I’m getting some clumps I’ll pull it out of the ice bath and stir in a tea towel or silicone trivet until the mixture is smooth and uniform again before popping it back in the ice bath.
Want to watch this project instead of read it?
Once your product is in its container, you’ve got three options for the rest of the cooling (basically, where you leave the thing to finish hardening): countertop/room temperature, fridge, and freezer. This can also make a big difference.
I usually try countertop cooling first simply to spare myself (and my product) the chance of spillage/droppage/general disaster in my attempt to convey it to the kitchen before it has solidified. I’d say countertop cooling works more often than not, so hooray for that!
If your product is mealy after a countertop cool, re-melt, re-trace, and try a fridge cool. If that doesn’t work, try again, finishing with a freezer cool. One of those should work. If not, I’d try a different level of trace and go back to countertop cooling.
Is your butter still uneven? Here’s how I’d start troubleshooting:
- Try a different level of trace. If your butter is too soft, aim for a thicker trace. An easy way to figure out the right level of trace is to replicate the experiment I demonstrate in the partner video for this blog post; make one big batch and take it from no trace through thick trace, pouring one bar at each stage. Once they’ve set up you’ll know what worked best.
- Try a different final cooling location. Counter didn’t work? Try the fridge or freezer.
- Think critically about your ambient temperature. Do you live somewhere 15°C (60°F) warmer than the formulator who created the formulation you’re trying to make? If so, that extra heat is probably the reason the butter is too soft/ isn’t setting up properly. It’s a location/ambient temperature problem, not a technique/trace problem. In situation like this, you will need to incorporate some sort of hardener into the formulation in order to raise its melting point. I would recommend a fatty thickener like Stearic Acid, Cetyl Alcohol, Cetearyl Alcohol, or C10-18 Triglycerides (Butter Pearls) in most body butter cases, though waxes can also work, depending on what you’re going for.
Some formulations to practice on
Remember that this technique takes practice, so don’t feel discouraged if it doesn’t work perfectly the first time! Keep working at it and you’ll get it 🙂
- Cinnamon Cocoa Massage Bars
- Green & Gold Body Butter Bars
- Sugar Plum Body Butter Bars
- Eucalyptus Mint Foot Butter
- Mango Mango Body Butter
- Hot Chocolate Body Butter Bars