Wednesday, November 14, 2012



Rock Candy experiments can be a great way to occupy children (and adults) during inclement weather, or as a great idea for a science project.  Plus, Rock Candy, unlike many other projects, allows the little researcher to eat the results!
You will need about a week to grow the sugar crystals and complete this experiment.

            Glass jar (if you want to make a larger batch, double the recipe and find another jar or two)
            Cotton Thread
            Paper Clip
            2 C granulated sugar
            1 C water
            ½ tsp flavoring extract of your choice (optional)
            Food coloring (optional)
1.   Sterilize your glass jar by washing in a dishwasher or by washing it thoroughly with hot water. Cut a piece of thread a few inches longer that the height of the jar. Cut a length of cotton thread a few inches longer than the height of the jar and tie or tape the thread to the pencil.  Lay the pencil across the jar opening and roll it until the thread sits one inch from the bottom of the jar.  To weigh down the thread and to make it hang straight, attach the paper clip to the bottom of the thread. 
2.  Roll the thread in sugar to enable the sugar crystals to grab on to the thread and start forming.  Set the thread aside to dry and begin preparing your sugar syrup.
3.  In a medium sized pan, bring your water to a boil.  Slowly add the sugar, one cup at a time being sure to stir after each addition. (It is normal for the sugar to dissolve slower as more sugar is added.)  Continue to boil and stir the syrup until all sugar has been dissolved. Remove pan from heat.
4. Add your optional colorings or flavorings at this time.  For extract, add ½ tsp. as stated above.  If you wish, you may add 2-3 drops of food coloring and stir until coloring is smooth and even.
5. Cool the sugar syrup for about 10 minutes before pouring into the jar or jars you prepared earlier. Place the pencil with the sugared cotton thread across your syrup filled jar then lower the string until it hangs about 1 inch from the bottom.
6. Cover the top of the jar loosely with a paper towel or plastic wrap and store undisturbed, in a cool place away from bright lights.
7.  Watch your experiment for changes.  You should see some sugar crystals forming within 2-4 hours. If there has been no change to the thread in 24 hours you will need  to boil the syrup again, adding another cup of sugar. Once this additional cup of sugar has been dissolved follow the instructions again starting with step five.
8. The rock candy can be allowed to grow to the size you wish, but don’t grow it too large or too close to the sides of the jar or it will begin growing on your jar. Once the rock candy has reached the size you wish, remove it and allow it to dry for a few minutes.  
9. Enjoy!  If saving for later (good luck getting the kids to do this), wrap in plastic wrap.
10.  If used as a science project, it is fun for the experimenting student or teacher to give out pieces of rock candy to the class, but it is rarely possible to make enough during the project to accommodate an entire class.  We suggest going on line to our Rock Candy Store where you can purchase bulk rock candy, boxed rock candy or rock candy by the piece/stick.

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