How do I grow crystals and How do I grow hard candy from crystals? ( this is for my science class)?

Question

I think to use Alum but what type of Alum. Anyone with a good recipe. Please help

Answer 1

You won't get candy from alum - alum is aluminum sulfate, it grows good crystals, but you don't want to eat them. To make candy, do the following:

-Make a supersaturated solution of sugar and water by boiling water, adding sugar and stirring until the sugar won't dissolve any more

-Add food colouring if you want colour, and food grade flavouring if you want other flavours (e.g. mint extract, vanilla, etc)

-Cool the solution to room temperature, pour it (without the undissolved sugar) into a tall container (large graduated cylinder works well)

-Get a length of cotton twine (don't use synthetic twine, cotton is best). Tie a weight (glass or stainless steel) to the twine. Tie the other end to a stick that fits over the top of the container. Drop the weighted end in and put the stick crosswise over the top.

Put the container in a place where it gets lots of ventilation and heat. A warm window sill or radiator works. As the solution evaporates, the sugar crystals will form on the string.