If you're making soy wax melts at home or crafting scents to sell, you have probably popped a batch out of the mould and found a white, powdery coating on the surface, or tiny beads of oil that weren't there when you poured. With so many makers pouring their Christmas stock right now, it is one of the questions we hear most often. In this guide, we explain why your wax melts are frosting, how to stop soy wax melts frosting and sweating, and how to tidy up melts you have already made.
Quick answer: Wax melts frost because soy wax is a natural wax that forms tiny crystals as it cools and ages, and these crystals leave a white, cloudy or patchy finish on the surface. Frosting is usually triggered by pouring too hot, cooling too quickly or temperature changes during storage. It is purely cosmetic and doesn't affect the scent throw or safety of your melts. To reduce it, pour within your wax's recommended temperature range, let your melts cool slowly at room temperature and store them somewhere cool and steady.
What Is Frosting on Wax Melts?
Frosting is a thin white layer, often with a crystal or feathery pattern, that appears on the surface of natural waxes such as soy. It can show up a few hours after pouring, or it can develop slowly over the days and weeks while your melts cure and sit in storage.
It happens because soy wax is made from vegetable oil, and as it cools, its fats naturally form crystals. On the surface, those crystals catch the light and look white. Paraffin wax doesn't frost in the same way, which is why frosting is often seen as a sign of a natural soy wax. To learn more about how different waxes behave, read our guide to everything you need to know about wax for wax melts.
Why Are My Wax Melts Frosting?
Most frosting comes down to temperature. These are the most common causes:
- Pouring too hot. Very hot wax takes longer to set, which gives it more time to form large crystals.
- Cooling too quickly. Putting melts in the fridge or freezer, or leaving them near an open window or a draught, shocks the wax as it sets.
- Cooling unevenly. Cold moulds, a cold worktop or a draughty room can cool one part of a melt faster than the rest.
- Temperature changes in storage. Melts kept in a cold garage, a warm car or on a sunny windowsill can frost over time, even if they looked perfect when you first unmoulded them.
- Overheating the wax. Heating soy wax well above its recommended temperature, or keeping it hot for a long time, can make frosting more likely. The technical data sheet for our Kerasoy 4120 advises against heating the wax above 85°C or for extended lengths of time.
- Adding dye. Dye doesn't cause frosting, but it makes it much easier to see, especially in darker and brighter colours.
Does Frosting Affect the Scent of Wax Melts?
No. Frosting is a cosmetic issue only. It doesn't change the amount of fragrance in your melts, and it won't affect the cold or hot scent throw. A frosted melt is just as safe to use as a smooth one.
If your melts look fine but don't smell as strong as you expected, the cause is something else, such as the melts not having cured for long enough or the fragrance load being too low. Our guide on how long wax melts need to cure explains why curing makes such a difference.
How Do You Stop Soy Wax Melts Frosting?
You can't stop soy wax from frosting completely, because it is a natural feature of the wax, but you can reduce it a great deal. Here are our top tips:
- Follow your wax's technical data sheet. For our Kerasoy 4120 Pillar Soy Wax, the data sheet suggests a pouring temperature of around 55 to 65°C. Add your fragrance just before you pour and stir it in thoroughly.
- Warm your moulds. Moulds should be clean and at least at room temperature. The Kerasoy 4120 data sheet notes that pre-heating moulds to around 45 to 50°C can be beneficial, and a quick blast of warm air from a hairdryer is an easy way to take the chill off silicone moulds.
- Let your melts cool slowly. Leave them to set undisturbed at room temperature, away from draughts, open windows and radiators. Never put them in the fridge or freezer to speed things up.
- Keep the room temperature steady. Pour in a room that stays at a similar temperature all day. A cold kitchen is one of the most common reasons makers start to see frosting in autumn and winter.
- Store your melts somewhere cool, dark and stable. Once they have set, keep them in airtight packaging, away from sunlight and heat. Avoid garages, sheds and cars, where the temperature can change a lot.
- Choose colours that suit soy wax. Pastel shades and undyed melts hide light frosting much better than deep reds, purples and black.
How Do You Fix Wax Melts That Have Already Frosted?
Light surface frosting can often be smoothed away with gentle heat. Pass a heat gun, or a hairdryer on a low setting, quickly over the surface of the melt until the very top layer turns glossy, then let it cool at room temperature. Keep the heat moving, because melting too much of the surface will spoil the shape or detail of your melts. Frosting can come back over time, so this is best done just before you package or photograph your melts.
If a whole batch is badly frosted, you can gently remelt it and pour it again at the right temperature. Heating scented wax a second time may cost you a little fragrance, and the new melts will need to cure again, so test one before you sell the batch.
Many makers also explain on their listings that natural frosting can appear on soy wax and doesn't affect the scent. Customers who choose soy wax melts usually appreciate knowing this.
Why Are My Wax Melts Sweating or Oily?
Sweating is when small beads of fragrance oil appear on the surface of your melts, leaving them greasy or oily to the touch. Unlike frosting, it means some of the fragrance oil hasn't stayed bound in the wax. The usual causes are:
- Too much fragrance oil. Our Kerasoy 4120 is designed for fragrance levels of 5 to 10%, and we recommend 6 to 10% for wax melts. Going over your wax's maximum won't make your melts any stronger, and the extra oil can seep out.
- Adding fragrance at the wrong temperature. If the wax is too cool, the oil may not mix in properly. We recommend adding fragrance at around 60 to 70°C, or at the temperature your wax's data sheet recommends.
- Not stirring for long enough. Stir gently but thoroughly for a couple of minutes, so the oil is fully mixed into the wax.
- Warm or humid storage. Heat and humidity can draw oil to the surface, so keep your melts somewhere cool and dry.
For a light sweat, blot the surface gently with kitchen roll and move the melts somewhere cooler. If it keeps happening, check your weighing and make sure you are within 6 to 10%. If you are already at 10%, try a slightly lower load with that scent, because the Kerasoy data sheet notes that some fragrances can react with the wax and bleed. Our guide to how much fragrance oil you need for wax melts has the simple calculation, and our tips on making strong-smelling wax melts explain how to get a great scent throw without overloading your wax.
Why Are My Wax Melts Cracking or Full of Air Bubbles?
Cracks and air bubbles are usually caused by cooling too quickly or by the way the wax is poured. Cracks often appear when melts are cooled in the fridge or in a cold room, so let them set slowly at room temperature instead. Air bubbles can form if you stir too hard, pour from too high or pour wax that has already started to set. Stir gently, pour slowly and close to the mould, and tap the mould lightly on the worktop after pouring to release any trapped air.
Which Fragrance Oils Are Best for Soy Wax Melts?
Every fragrance oil in our range is suitable for soy wax melts at 6 to 10%, and each one is professional grade and highly concentrated, so a little goes a long way. Here are some popular choices for winter and Christmas melts, all available from 10g for testing:
- Chocolate Orange Fragrance Oil: a crowd-pleasing classic, with orange zest, vanilla and honey over rich notes of chocolate, sugar and cocoa. From £1.99.
- Frosted Eucalyptus Fragrance Oil: crisp eucalyptus, mandarin and green apple, with spruce, jasmine and rose water on a base of herbs, sweet balsam and honey. The only kind of frosting you'll want in your melts. From £1.99.
- Ice Fairy Fragrance Oil: candy floss and bubblegum with a light floral heart and a soft, creamy base of musk and vanilla. A sweet and sparkly winter favourite. From £1.99.
- Nordic Spruce Fragrance Oil: pine and eucalyptus with fir needle, sandalwood, cedarwood and vanilla. The Christmas tree scent customers ask for. From £2.49.
- Toasted Marshmallow Fragrance Oil: golden syrup and caramel with vanilla, malt and white woods. Perfect for Bonfire Night and cosy winter evenings. From £1.99.
- Ginger Flump Fragrance Oil: cinnamon, ginger and nutmeg on a warm base of vanilla and tonka. From £1.99.
- Woodland Walk Fragrance Oil: mandarin, rosemary and bergamot with crisp leaves, rose, musk and vanilla. From £2.49.
- Fresh Linen Fragrance Oil: the comforting scent of freshly laundered sheets, and a year-round best seller for any range. From £2.30.
For your wax, our Kerasoy 4120 Pillar Soy Wax is a vegan, biodegradable soy wax made in the UK for wax melts and pillar candles. From £7.99 for 1kg. You'll find it alongside our other waxes in our wax making supplies collection.
You can browse every scent in our wax melt fragrance oils range, or see our seasonal favourites in the Autumn and Christmas fragrance oils collection. For more festive ideas, read our guide to the best Christmas fragrance oils for wax melts.
Why Choose Aroma Ninjas for Wax Melt Supplies?
- Professional grade and highly concentrated: a little goes a long way.
- Strong cold and hot scent throw in soy wax melts.
- Soy wax made for wax melts: Kerasoy 4120 comes with a technical data sheet to help you get your temperatures right.
- Safety documents for every oil: CLP, SDS, IFRA and allergen documents ready to download from each product page.
- Sizes for every stage: from 10g bottles for testing new scents up to 1kg for production.
- Free UK mainland delivery on orders over £125 (excluding VAT).
FAQs
Is frosting on wax melts bad?
No. Frosting is a natural feature of soy wax and is purely cosmetic. It doesn't affect the scent throw, and frosted melts are just as safe to use as smooth ones.
Why have my wax melts turned white?
In most cases, a white, powdery or patchy finish is frosting. It is more noticeable on coloured melts and often appears after the melts have been stored somewhere that gets colder or warmer during the day. Keeping your melts at a steady room temperature will help to reduce it.
Should I put wax melts in the fridge to set faster?
No. Cooling wax melts in the fridge or freezer is one of the main causes of frosting and cracking. Let them set slowly at room temperature, and allow at least 24 hours before you package them.
Can I still sell wax melts that have frosted?
Yes. Frosting doesn't affect the quality or scent of your melts, and many makers sell soy wax melts with a light frost. If you prefer a smoother look, try the heat gun tip above before packaging. Whatever your melts look like, make sure they are fully cured and correctly labelled. Our guide to whether wax melts need CLP labels explains what has to go on the label.
Final Thoughts
So, why are your wax melts frosting? In almost every case, it is simply soy wax doing what natural wax does, helped along by pouring too hot, cooling too fast or storing your melts somewhere that changes temperature. Pour within your wax's recommended range, warm your moulds, let your melts cool slowly and store them somewhere cool, dark and steady, and you'll see far less frosting and sweating.
If you're new to wax melts, our step-by-step guide on how to make wax melts at home covers the basics. Explore our full range today and find the perfect fragrance oil for your wax melts, whether you're crafting for fun or to sell!