How to Repurpose Used Cooking Oil into Eco-Friendly Candles

How to Repurpose Used Cooking Oil into Eco-Friendly Candles

How to Repurpose Used Cooking Oil into Eco-Friendly Candles


With rising awareness about sustainability and reducing waste, many people are looking for ways to repurpose used household items. One simple yet creative way to give used cooking oil a new life is by turning it into homemade candles. Not only is this a eco-friendly craft, but it can also make wonderful gifts. In this article, I will share everything you need to know to successfully repurpose used cooking oil into candles.

What You Need

Turning used cooking oil into candles is an easy DIY project. Here’s a list of supplies you’ll need:

  • Used cooking oil – This can be oil leftover from deep frying or sautéing. Strain out any food particles.
  • Wicks – Purchase candle or braided cotton wicks.
  • Fragrance oil (optional) – For scented candles, use essential oils or candle fragrance oils.
  • Containers – Glass jars or tins make great candle holders. Make sure they are heat resistant.
  • Double boiler – This allows you to melt the cooking oil safely.
  • Thermometer – To monitor the oil temperature.
  • Spoon – For stirring the wax.
  • Dye (optional) – Add dye for colored candles. Use candle dye blocks.

The most essential requirements are used cooking oil, wicks and containers. Additional ingredients create customized candles.

Rendering the Used Cooking Oil

Before the used oil can be turned into candles, it needs to be cleaned of any food debris and impurities. Here are the rendering steps:

  • Strain – Pour the used oil through a fine mesh strainer or cheesecloth to remove any food particles.

  • Heat – Pour the strained oil into a double boiler or makeshift double boiler. Heat it until it reaches 185°F to 200°F. This evaporates any remaining moisture.

  • Cool and strain again – Once heated, remove the oil from heat and let it cool. Strain it again to remove any debris that settled at the bottom.

The rendered oil should look clear and have no remnants of food. Now it is ready to be transformed into candles!

Making the Candles

With the rendered cooking oil prepared, now comes the fun part – turning it into candles!

Step 1: Adding Fragrance and Dye

If you want scented or colored candles, now is when to customize them.

  • For fragrance, add a few drops of essential oils or candle fragrance oils for each pound of oil.

  • For dye, add candle dye blocks shaved into the oil. Mix until you achieve the desired color intensity.

Step 2: Melting the Wax

Re-melt the cooking oil in a double boiler over medium heat until it reaches 185°F to 200°F.

Step 3: Preparing the Wicks and Containers

While the wax is melting:

  • Cut the wicks to about 1/2 an inch longer than the height of the container.

  • Attach wick sticks to the bottom of the containers if using jars or mugs.

  • Place wicks in the center of the containers.

Step 4: Pouring the Candles

Once the wax has fully melted, remove it from heat. Let cool slightly so it thickens a bit, about 5 minutes. Then carefully pour the wax into the prepared containers.

Make sure to leave some headspace at the top for the melting wax.

Step 5: Cooling and Final Touches

Allow the candles to fully cool and harden overnight. Trim the wicks to 1/4 inch before lighting. Add any additional decorative touches like beads, sea shells, or leaves.

And that’s it – you’ve repurposed used cooking oil into handcrafted, eco-friendly candles! Enjoy your homemade creations.

Tips for Best Results

Here are some tips to help your upcycled candles turn out perfect:

  • Use cooking oils with low saturation like canola, sunflower, or vegetable oil. Avoid olive oil or oils with strong flavors.

  • Wick size matters. Choose smaller wicks for soft oils like canola or soybean. Use larger wicks for firmer oils like palm or lard.

  • Cool candles slowly to prevent sinkholes and cracks. Let harden at room temp for 24 hours.

  • Add 10% beeswax to raise the melt point and make firmer candles.

  • Reuse small glass jars or mugs to give candles a rustic, eco-friendly look.

  • Combine used oil from different sources like deep frying, sautéing, etc. Strain well to remove all food particles.

Creative Uses for Upcycled Oil Candles

The possibilities are endless when repurposing cooking oil into candles! Here are some creative ways to use your homemade oil candles:

  • Make scented candles with essential oils to set the mood in any room. Some great scents are lavender, eucalyptus, chamomile.

  • Craft unique votive candles to give as gifts for any occasion. Personalize with dyes, scents, and embellishments.

  • Create birthday cake or dessert-scented candles for a fun party decoration.

  • Use handpainted mason jars or tumblers as rustic candle holders.

  • Make colorful painted tin candles and use to illuminate outdoor spaces.

  • Add seashells or beads to make beach-themed candles for relaxation.


Upcycling used cooking oil into candles takes something you would normally throw out and transforms it into something beautifully useful. Not only is it a budget-friendly craft, but it reduces waste in an eco-friendly way. With just a few easy steps and basic ingredients, you can make lovely candles to enjoy or give as heartfelt gifts. So next time you fry up some food, save that leftover oil to make one-of-a-kind candles!