Edible Candle

Don’t leave this candle in the wind. Eat it instead!

Australian Curriculum links

  • Science > Chemical Sciences > Year 3 > ACSSU046
  • Science > Chemical Sciences > Year 6 > ACSSU095

You'll need

  • Wax candle
  • Lightly boiled potato cut in the shape of a candle (an apple corer works well)
  • Slivered almonds
  • Lighter or matches
  • Heatproof plate

Try this

Safety precaution: This activity should be performed under adult supervision. People who are allergic to tree nuts should not do this activity and should leave the room if this activity is performed by others.

  1. Put the wax candle on the heatproof plate.
  2. Light the wax candle.
  3. Observe what part of the candle is burning.
  4. Blow out the wax candle.
  5. Let the wax candle cool.
  6. Remove the wax candle from the heatproof plate.
  7. Push one almond sliver into the top of the potato to make the wick.
  8. Put the edible candle on the heatproof plate.
  9. Use the lighter or matches to light the almond.
  10. Observe what part of the candle is burning.
  11. Blow out the candle.
  12. Let the candle cool.
  13. Eat the potato and almond candle.

Further investigation

Try using other nuts as fuel in your edible candle. Measure which nuts burn for the longest or the shortest amount of time.

What's happening?

For a fire to occur there must be three things: energy (usually heat), oxygen and fuel. In both candles, the oxygen is in the air surrounding the candle and the initial heat energy comes from the lit match or lighter. In a wax candle, the wax vapour is the fuel. The fuel in the edible candle is the almond.

A candle is made of two parts, a wick and wax. The wax is often paraffin wax, a wax that comes from crude oil, or beeswax, a wax produced by honey bees. The wick is made of an absorbent material. When the wick is lit, the heat from the flame melts the wax just near the exposed wick. The wick absorbs the liquid wax and the liquid wax moves up the wick by capillary action. When the liquid wax reaches the flame, the liquid wax vaporises and becomes wax vapour (a gas). The wax vapour is the fuel that allows the candle to continue to burn.

The edible candle is also made of two parts, the almond and the potato. Almonds contain proteins, fats and carbohydrates. Lighting an almond on fire releases the stored chemical energy in these fats, proteins and carbohydrates as heat. Because almonds contain a high percentage of fat and fat contains a lot of stored chemical energy, the almond can burn for quite some time. The potato simply acts as a base for the almond to sit in; it doesn’t burn or provide any fuel for the flame.

Real world links

In a process called cellular respiration, our bodies release the stored chemical energy in the food we eat. Some of this stored chemical energy is transformed into the type of energy that our cells can use to do work and the rest of the chemical energy turns into heat. We wouldn’t be able to run, skip, jump and perform fun, science experiments without this energy. You can learn how much stored chemical energy is in your food by reading the nutritional information on the packet.