On my first attempt to make hard candy I discovered that the selection of molds available locally was pretty limited. Either the molds were not for high temperature or they were teddy bears or lollypops. So I decided to make my own.
I have seen corn starch mold used for industrial candy production so I figured it was worth a try.
1/2 sheet tray - to hold the mold
1/2 sheet size cooling rack
Full Sheet tray - help to contain mess
Hot Glue gun
Corn starch - 4 lbs for 1/2 sheet tray
Square dowel to hold the positive shape
Some kind of positive shape that can be attached to dowel. I used 1" jewels from hobby lobby. I'll call them a die as you can use any shape that you can find to make the mold.
Calipers - if you are really a geek
Molten Hard candy - you can find multiple instructables on this topic
I measured the 1/2 sheet tray. It's inside dimensions are 17.25"x12.25".
The dowel is 36" long. I need it to be at least 13" long so it can be used as the 'stamp'. To make it easy I cut the dowel in half to 18"
Measure out 12.25" in the approximate center of the down and mark with a pencil.
I arbitrarily picked 13 dies for the stamp. This was the quantity in the pack.
Since the width of the tray is 12.25" and there will be 13 jewels that means there will be a spacing of 0.942" between each. This is where the caliper comes into play. Open the calipers to 0.942" and place one tip on the pencil mark. Since the dowel is made from soft wood it's easy to make a dent in it with the caliper. Make a dent each 0.942" distance along the dowel. Then draw a line at each dent mark and you'll have a perfectly spaced guide for the dies.
Using the dowel gently smooth out the starch so that it completely fills the tray. You don't want any gaps or holes in the surface. As the starch falls off the edge into the full size sheet tray you can pick it up and use it to fill in the gaps. Repeat this process until you get a smooth even surface.
Place tray in the fridge for at least an hour. This will harden the candy.
Quickly flip the tray over. If you do it right the starch will stay in the tray until it's face down in the full size sheet tray.
Take the tray off and set it aside. Shake the cooling rack to allow the starch to fall through the grate.
After shaking off a bulk of the starch knock each candy with the back of a spoon to get even more off.
Note: You should be able to recover about 98% of the corn starch so that you can used it next time.
To help prevent this from happening I coat the candy in powdered sugar. To make sure they are coated evening I used my marinating tumbler.
Add about 2 cups of powdered sugar and add the candy. Set it to tumble for about 20 min.
After tumbling, place the candy on a cooling rack on a fresh tray. This will let you recover the powdered sugar for later use.
As you did before, shake the rack to knock off the sugar.
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