These cheeky little “lumps of coal” themed scrubby nuggets are a delightful, gift-able bath treat. I’ve made a ton of scrubs since 2011, and scrub nuggets deserve way more love because they solve two of the biggest problems of the far-more-popular whipped, self-emulsifying anhydrous sugar scrub.

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The first problem is the tendency of such scrubs to get hard and crumbly. They’re delightful and fluffy when you first make them, but a day or two later you might find your fluffy scrub is now a solid lump in a jar. Boo. You can try to fix that seizing up by including fewer hardening ingredients like cetearyl alcohol and butters in your scrub, but in warmer weather that can lead to a scrub that melts and separates.

Because scrub nuggets are supposed to be solid, that hardness becomes an asset! I’ve formulated these to have a higher melting point that you’d typically want in a body butter bar because they’ll be applied in a hot bath or shower, so there’s plenty of warmth to go around and get them melting and moving.

The second problem has to do with shelf life. If you opt not to use a preservative in a self-emulsifying sugar scrub, you can’t get any water in the scrub or it can spoil. This means you have to portion out a scoop into a shower-safe container before each bath or shower. This works well, but is a bit of a hassle, and is something gift recipients might not remember to do.

Of course, you could just include a preservative, but you can also go the nugget route! Scrub nuggets are designed to be a single scrubby serving, so you can just grab one and take it into the shower or bath without needing a second container. Easy peasy!

To reduce the amount of fat going down the drain, the bulk of these scrub nuggets is water-soluble, scrubby white sugar and silky soft corn starch. All that white powdery stuff is coloured charcoal-y with a touch of black mica, and then bound together with just enough creamy stuff.

That creamy stuff is a blend of satiny, gorgeous kokum butter and conditioning BTMS-50. Kokum butter is a firm butter that’s similar to cocoa butter, but I find it’s not quite as brittle. You can use cocoa butter instead if you already have some, but I chose to use kokum butter because of the current cocoa butter shortage. Kokum butter is about half the price of cocoa butter right now, and some suppliers have stopped selling cocoa butter all together (sob).

BTMS-50 is an emulsifier, so when you massage a scrub nugget into wet skin it’ll turn into a creamy, lotion-y scrub. When you’re done, the BTMS-50 ensures it rinses off easily and mixes into your bath water rather than floating on top and creating a serious slipping hazard when you drain the tub. I chose BTMS-50 over a non-ionic emulsifier like Emulsifying Wax NF or polysorbate 80 because it’s cationic, which means it leaves a lingering “conditioned” feeling on your skin after rinsing that is absolutely delightful.

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Making them is a simple melt, stir, pour, and chill. The finished nuggets make a delightful gift and wonderful bath treat. Enjoy!

Relevant links & further reading

• Kokum Butter in the Humblebee & Me Encyclopedia
• BTMS-50 in the Humblebee & Me Encyclopedia
• Coloured Mica in the Humblebee & Me Encyclopedia
• Corn Starch in the Humblebee & Me Encyclopedia
• Tocopherol (Vitamin E) in the Humblebee & Me Encyclopedia
• How long will ______ last? What is its shelf life? in the Humblebee & Me FAQ
• Other “Lumps of Coal” themed DIYs
  • Lumps of Coal Christmas Bath Bombs
  • Charcoal & Bentonite Clarifying Shampoo Bar
  • Lumps of Coal Christmas Soap

Lumps of Coal Scrub Nuggets

Heated phase
40g | 20% kokum butter (USA / Canada)
20g | 10% BTMS-50 (USA / Canada)

Dry phase
0.6g | 0.3% black mica
120g | 60% white sugar (USA / Canada)
18g | 9% corn starch

Cool down phase
1g | 0.5% fragrance
0.4g | 0.2% Vitamin E MT-50 (USA / Canada)

Prepare a water bath by bringing about 3cm/1″ of water to a bare simmer over low to medium-low heat in a small saucepan.

Weigh the heated phase ingredients into a small heat-resistant glass measuring cup and place the measuring cup in your prepared water bath.

While the heated phases melts, stir the dry phase together in a bowl until you have a uniform grey powder.

After about 20 minutes, the kokum butter should be melted and the BTMS-50 will probably be most of the way there. If your BTMS-50 is like mine (really not interested in melting that final bit), pop the measuring cup in the microwave for 20 seconds or so to get the job done.

Once your heated phase is fully melted, add the dry phase, and stir the mixture with a flexible silicone spatula to combine everything. If it starts to cool down & thicken up enough that it’s hard to stir, pop the measuring cup back in the water bath, stirring, until it loosens up.

Add the cool down phase, stir, and then pour the batter into moulds that are no larger than about 15g (0.5oz)—I found anything larger wasn’t easy to use up in one go, defeating the point of a single serving scrub nugget. I mostly used a silicone honeycomb mold (USA / Canada) that holds 5mL (1 tsp) per hexagon.

Pour as quickly—but neatly—as you can manage. If the mixture starts to get too thick to pour, scrape it down and pop it back in the water bath for a moment to re-melt, and then keep pouring.

Once you’ve finished pouring, transfer the moulds to the fridge to set up.

When everything is nice and firm, remove the moulds from the fridge and unmould your scrubby little nuggets.

Package the scrub nuggets in a wide-mouthed jar or tin so you can easily reach in and grab one before heading into the shower or bath.

To use, in a hot bath or shower, massage a single nugget into soaking wet skin. Scrub away, rinse off the sugar, and enjoy your soft, moisturized, conditioned skin.

Shelf Life & Storage

Because these scrub nuggets do not contain any water, they do not require a broad-spectrum preservative (broad spectrum preservatives ward off microbial growth, and microbes require water to live—no water, no microbes!). Be sure keep them as a “single serve” scrub—do not store the jar in the shower, and once one gets wet, finish it. The dry nuggets should easily last a year. If you plan on giving these scrub nuggets away, make sure your recipients know not to store the jar in the shower.

Make sure these don’t get too hot or they will melt—so don’t leave them on a radiator or in a hot car.

Substitutions

As always, be aware that making substitutions will change the final product. While these swaps won’t break the formulation, you will get a different final product than I did.

• As I’ve provided this formulation in percentages as well as grams you can easily calculate it to any size using a simple spreadsheet as I’ve explained in this post. As written in grams, this formulation will make 200g. How many nuggets this will make depends entirely on how large each nugget is. This could be 40 × 5g (0.18oz) nuggets, ~13 × 15g (0.5oz) nuggets, or anything in between.
• To learn more about the ingredients used in this formulation, including why they’re included and what you can substitute them with, please visit the Humblebee & Me Encyclopedia. It doesn’t have everything in it yet, but there’s lots of good information there! If I have not given a specific substitution suggestion in this list please look up the ingredient in the encyclopedia before asking.
• You can try Cocoa Butter instead of kokum butter. If you do this, start with a small batch so you can ensure the melt speed still works for you.
• You can try a different solid emulsifying wax instead of BTMS-50, but again—start with a small batch, and anticipate some re-development work. BTMS-25, while also cationic, has far more solidifying ingredients in it and will raise the melting point of the nuggets. I did try Olivem1000 while developing this formulation and I hated the way it felt.
• You can try activated charcoal instead of mica, but I haven’t tested that. Start small and make sure it doesn’t make a big mess in your tub.
• You can use a different colour of mica for a different theme.
• You could try salt instead of sugar if desired.
• Arrowroot starch, tapioca starch, or any other silky, fine starch will work instead of cornstarch.
• If you’d like to incorporate an essential oil, please read this.