Glass Candy - cooking recipe

Ingredients

3 cups sugar
1/2 cup water
1 teaspoon white vinegar
1 teaspoon butter
food coloring (red, yellow, green, or others) (optional)
flavoring (lemon, lime, strawberry, or others) (optional)
1 pinch salt

Preparation

In a heavy-bottomed pot, bring the sugar, water, and vinegar to a medium boil.
Stir carefully so all the sugar is dissolved.
Brush down the sides with a pastry brush dipped in water if crystals begin to form.
Cook for atleast 20 minutes.
Add the butter and cook for another 10 minutes until you reach the \"crack\" stage on the candy thermometer (290 degrees).
At this point, when a bit of the mixture is dropped into cold water, it instantly turns brittle.
Meanwhile prepare a muffin tin by greasing well with vegetable shortening. These will serve as your moulds.
Remove the molten candy from the stove and stir in the food coloring and flavouring of your choice.
Now pour 1/8 to 1/4 inch of candy into each muffin cup.
Cool completely.
When cooled, turn upside down and give a few taps on the bottom and the candies should pop out.
Wrap each in waxed paper.