70/30 sugar/corn syrup
dissolve at 225degF/107degC
boil to 280degF/138degC
Brown corn syrup will give an OK brown glass colour...clear syrup with food colour for anything else. Remove from the heat and let stand until it just begins to solidify then pour into your mold (see below), cork and rotate all around to keep the surface evenly coated (wear gloves!). The solution will begin to harden on the walls of the mold and when you have
sufficient build up (experiment is required!) pour off excess liquid and keep turning until cool enough not to slump (I have someone spray water or just pass it under running water a few times. Remove from mold. We have made glasses by this method that actors actually drank out of before breaking.
2 c. Water
1 c. White Corn Syrup (Karo)
3 1/2 c. Sugar
1/4 tsp. Cream of Tartar
1) Mix the water, corn syrup, sugar and tartar together in the pot and bring it to a boil on the stove (at about 220 F).
2) Leave it boiling until it reaches 300 F, which will take about 45 minutes. The mixture should be thick, with almost all the water boiled off.
3) As soon as it hits 300 F, pour it into whatever mold you're using and let it cool.
- Sugar glass doesn't last long (warps or goes sticky) so make it close to the time when you plan to use it.
- Keep it out of moist areas and direct sun. The same as a lolipop it will melt or go gooey.
- The sugar can attract ants and other bugs so keep it packaged in plastic, etc. until you use it.
- Though only sugar, the glass can have sharp edges/points when broken, so be careful when handling.
- For more information on breakaway glass, molding, and casting of other kinds, we recommend this book:
The Prop Builder's Molding & Casting Handbook
by Thurston James