Why Does Honey Crystallize?
Talk It Over
Have you ever noticed that honey crystallizes in a jar when you leave it in the cupboard for a long time? What is crystallization? What might make it happen faster?
- 5 small containers
- Stick-on labels and pen
- Cotton ball
- Vegetable oil
- Measuring spoons
- Kitchen timer
- Digital instant-read thermometer*
- Make five labels marked 0, 1, 2, 3, and 4. Attach one label to each of the five containers.
- Dip the cotton ball in oil. Use it to wipe the inside of a measuring tablespoon. (This will make the honey slide out of the measuring spoon easily.)
- Measure 1 tablespoon of honey into each of the five containers. To keep your measurements accurate, wipe the inside of the spoon with the oily cotton ball after each measurement.
- To the container labeled 1, add 1 teaspoon of water. Add 2 teaspoons of water to the container marked 2, 3 teaspoons to container 3, and 4 teaspoons to container 4. To the container marked 0, add no water. It will contain only honey.
- With a toothpick, stir the honey and water in each container until well mixed. Stir the honey in container 0 so it gets the same stirring treatment as the mixtures.
- Put the containers together on a shelf in the freezer. Set the timer for 2 minutes.
- After 2 minutes, open the freezer and check the containers for signs of crystals. If you see crystals in any one of the containers, take the temperature of the container's contents with the digital thermometer.
- Keep timing and checking every 2 minutes. Measure temperatures in each container when you first see crystals forming.
- Make notes of anything else you observe, including how long it takes for the contents of each container to crystallize completely.
Pour the honey from the jar into the measuring spoon. Don't put the spoon into the honey jar. You'll get oil in the honey and spoil it for eating. Also, don't taste or eat the honey you use for this experiment.
Put 2 tablespoons of honey in one container. Put 1 tablespoon of honey mixed with 1 tablespoon of water in another. Put both in the freezer and observe every 2 minutes. Write down how long each takes to form crystals.
- Obtain several different kinds of honey, including clover honey and orange flower honey. Measure and compare the temperatures at which pure samples of each begin to crystallize.
- Test other sugar solutions using the "Go" procedure. You might try molasses, maple syrup, and corn syrup. Note similarities and differences and try to explain them.
Show Your Results
Record times in a table like this for "Go Easy":
|Material Tested||Time It Took to Crystallize|
|Honey and water|
Make a bar graph that compares crystallization time for pure honey and honey mixed with water.
For "Go," use a table like this:
|Amount of Water (Added to 1 Tbsp. of Honey)||Time When Crystals First Appear (Minutes)||Temperature (°C) When Crystals First Appear|
Use your table to make a bar or line graph of water content (on the horizontal axis) and time to crystallization (on the vertical). Make a separate graph for the temperature of crystallization.
For "Go Far," make bar graphs comparing the crystallization temperature of different kinds of honey or different sugary solutions. Collect data and make a line graph that a friend could use to figure out the water content of any honey solution, knowing only the temperature at which crystals first appear.
Tips and Tricks
- Don't use a digital thermometer from the health section of your pharmacy or discount store. It is designed to measure human body temperatures and won't read low enough for this experiment. Choose a thermometer from the kitchen department. It will measure temperatures to freezing and below.
- Many thermometers read temperatures in both Fahrenheit (°F) and Celsius (°C). You can use either for this experiment; just be careful not to confuse them. If you want to work as scientists do, use °C.
- Keep the tip of the thermometer in the liquid. If it touches the container, you won't get an accurate reading.
- This is a good experiment to repeat several times. Averages of your times and temperatures over several trials are better than the results of a single trial alone.
Warning is hereby given that not all Project Ideas are appropriate for all individuals or in all circumstances. Implementation of any Science Project Idea should be undertaken only in appropriate settings and with appropriate parental or other supervision. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. For further information, consult your state’s handbook of Science Safety.