Why Use Stearic Acid in Candles

Role of Stearic Acid in Candles

If you’re a fan of candles or have ventured into the world of candle making, you’ve likely come across stearic acid. But what exactly is it, and why is it used in candles? Read on as we explore stearic acid’s role in candle making, its benefits, and how it compares to other additives. By the end, you’ll have a better understanding of why stearic acid is such a popular choice for candle makers.

What is Stearic Acid?

Stearic Acid’s Chemical Properties

Stearic acid is a long-chain fatty acid commonly used as a hardening agent and emulsifier in various products. It has a molecular formula of C18H36O2 and is a white, waxy solid at room temperature. Its melting point ranges between 68-69°C, making it suitable for use in candles.

Sources of Stearic Acid

Stearic acid can be derived from both animal and vegetable sources. Animal-based stearic acid is typically obtained from tallow, while vegetable-based stearic acid comes from palm oil, soybean oil, or cocoa butter. The source of stearic acid doesn’t significantly affect its properties or performance in candles.

What Is Stearic Acid? Its Uses & The Consequences For Your Health.

The Role of Stearic Acid in Candles

Hardening Agent

Stearic acid serves as a hardening agent in candles, adding firmness to the wax. This helps prevent candles from melting or becoming misshapen in warmer temperatures, ensuring they maintain their appearance and structural integrity.


In addition to its hardening properties, stearic acid adds opacity to candles. This means that the candles become less transparent, giving them a more polished, professional look.

Burn Time

One of the most significant benefits of using stearic acid in candles is its ability to prolong the burn time. By increasing the hardness of the wax, stearic acid allows candles to burn slower and more evenly, providing a longer-lasting and more enjoyable experience for users.

Benefits of Using Stearic Acid in Candles

Improved Candle Quality

Using stearic acid in candle making results in a higher-quality product. The added hardness and opacity create a more aesthetically pleasing candle, while the increased burn time offers users more value for their money.

Enhanced Fragrance Retention

Stearic acid also improves fragrance retention in scented candles. By binding with the fragrance oils, stearic acid helps ensure that the scent remains strong and consistent throughout the life of the candle.

Environmentally Friendly Option

When sourced from vegetable-based materials like palm oil, soybean oil, or cocoa butter, stearic acid can be an environmentally friendly option. Unlike paraffin wax, which is derived from petroleum, vegetable-based stearic acid is renewable and has a lower environmental impact.

Stearic Acid vs. Other Additives

Comparing Paraffin Wax

Paraffin wax is another common additive used in candle making. While it does offer some benefits, such as a lower cost and longer burn time, paraffin wax is derived from petroleum, making it less eco-friendly than vegetable-based stearic acid. Additionally, some people may find the fumes released by paraffin wax candles to be irritating.

Beeswax: A Natural Alternative

Beeswax is a natural alternative to stearic acid that is derived from bees. It is a popular choice for those seeking a more environmentally friendly option. However, beeswax can be more expensive than stearic acid and doesn’t offer the same level of hardness or opacity.

Soy Wax: A Plant-Based Option

Soy wax is another plant-based alternative to stearic acid. While it is an eco-friendly option, soy wax tends to be softer than stearic acid, which can result in a shorter burn time and a less stable candle structure.

How to Use Stearic Acid in Candle Making

Sourcing Stearic Acid

To use stearic acid in your candle making, first, you’ll need to source it. You can find stearic acid from various suppliers, both online and in brick-and-mortar stores. Be sure to choose a reputable supplier, and opt for vegetable-based stearic acid if you’re looking for an eco-friendly option.

Mixing with Wax

Once you have your stearic acid, you’ll need to mix it with your chosen wax. Typically, you’ll want to use a ratio of 3-5% stearic acid to wax, depending on the desired hardness and opacity. To ensure an even blend, heat the wax and stearic acid together until both are fully melted, then stir to combine.

Adjusting Ratios

Don’t be afraid to experiment with different ratios of stearic acid to wax to achieve your desired candle properties. Keep in mind that too much stearic acid can lead to a brittle candle, while too little may not provide the desired hardness or burn time.

Safety Considerations

As with any candle making process, it’s essential to follow safety precautions when working with stearic acid. Always use heat-resistant gloves and goggles when melting and mixing your wax and stearic acid, and work in a well-ventilated area to avoid inhaling fumes. Additionally, never leave your melting wax and stearic acid mixture unattended.


Stearic acid is a popular additive in candle making due to its ability to improve hardness, opacity, and burn time. When sourced from vegetable-based materials, it can also serve as an eco-friendly option. By understanding its properties and benefits, as well as how to use it in your candle making process, you can create higher-quality, longer-lasting candles for yourself and others to enjoy.

FAQs – Frequently Asked Questions

Is stearic acid safe for use in candles?

Yes, stearic acid is safe for use in candles when handled and used correctly. Be sure to follow all safety precautions when working with stearic acid and other candle-making materials.

Can I use stearic acid in soy wax candles?

Yes, you can use stearic acid in soy wax candles to increase hardness and improve burn time. Just keep in mind that you may need to adjust the ratio of stearic acid to soy wax to achieve the desired properties.

Do I need to use stearic acid in my candles?

While using stearic acid is not mandatory, it does offer various benefits, such as improved hardness, opacity, and burn time. It can also enhance the overall quality and appearance of your candles.

What can I use as an alternative to stearic acid?

Some alternatives to stearic acid include beeswax, soy wax, and paraffin wax. Each of these alternatives has its own unique properties and benefits, so you may need to experiment to find the one that best suits your needs.

Is stearic acid vegan?

Stearic acid can be derived from both animal and vegetable sources. If you’re looking for a vegan option, make sure to choose stearic acid that is sourced from plant-based materials, such as palm oil, soybean oil, or cocoa butter.