Edible Crystals

When our Borax Easter Crystals were formed, C and R both said they looked like candy.  Of course, I told them not to put the crystals anywhere near their mouths.  Then I promised to make them rock candy.

I followed the directions from Science Bob:

First, I attached a clothespin to each lollipop stick (one for each rock candy) and checked to make sure that the sticks hung down in our glasses to about 1 inch from the bottom of the glass.  I adjusted the sticks after taking this picture, but you get the idea.

Then, I removed the clothespin/stick contraption and put it aside until needed.  I poured two cups of water into a pot and brought it to a boil.  I added 1/4 cup of sugar and stirred until it dissolved, and continued to add sugar in 1/4 cup increments until it would not dissolve.  I think I used about 4 cups of sugar.

R took this picture of me adding the sugar to the pot.  I thought you would like the baby bump photo.  This was taken on Friday, April 9th and I was exactly 18 weeks pregnant on that day.  Okay, back to the candy.

Once the sugar would no longer dissolve, I turned off the heat and let the mixture cool for 20 minutes.  At that time, I poured it into the two glasses and put the stick/clothespin contraptions back in the jars.  (The stick should hang straight down and should not touch the sides of the glass.)  I added blue food coloring to C's candy mixture and purple food coloring to R's mixture.

The directions I read said to add a lot, and I did.  I couldn't even tell if the crystals were forming because the solution was so dark!

According to Science Bob, it takes three to seven days for the sugar crystals to grow.  Quite a few people left comments saying they were unsuccessful in their attempts to make rock candy, so we left the jars undisturbed for seven days with the hopes that our patience would pay off!

On day seven, I slowly pulled the lollipop stick out of the first jar, but I quickly realized that the crystals did not form on the stick.  I dumped the contents of R's jar into a bowl and I had a very thick sugary syrup.

At the top of the jar there were a few crystals, so I broke those off for R.

They tasted just like rock candy, but we were kind of hoping for more, and they are just so much prettier on sticks!

We checked out C's rock candy later in the day (when he got home from school) and his was the same but in blue, so I see no need to post more photos!

I did some research about rock candy problems.  It is not humid here right now, so that wasn't our problem.  I think we may have had better luck if we strained the solution before putting it in the jars to make sure no undissolved sugar ended up in the jars, and maybe string would have worked better than the sticks.  Oh well, at least we got a few crystals!

The science behind rock candy (this is from Science Bob):
The water and sugar made a super saturated solution so the water could only hold the sugar if both were very hot.  As the water cooled, the sugar was supposed to come out of the solution and form crystals on the stick.  The stick (and sometimes the glass) act as a seed for the sugar crystals to grow on.

Check out Science Sunday at Adventures in Mommydom for more cool science projects that probably worked better than ours!