In a large saucepan, combine the granulated sugar, water, and white vinegar. Mix well until the sugar is fully dissolved.
Place the saucepan over medium heat and insert the candy thermometer into the mixture. Stir occasionally with a wooden spoon to prevent the sugar from burning.
Heat the mixture until it reaches a temperature of 234°F (112°C). This is the soft-ball stage. It may take around 15-20 minutes for the mixture to reach this temperature.
Once the mixture reaches the soft-ball stage, remove it from heat and allow it to cool slightly for a few minutes.
While the mixture is cooling, prepare a mixing bowl by lining it with parchment paper. Make sure the parchment paper extends beyond the edges of the bowl to make it easier to remove the fondant later.
Pour the slightly cooled mixture into the prepared mixing bowl. Be careful as the mixture will be extremely hot.
Allow the fondant to cool and harden completely. This may take several hours or overnight, depending on the ambient temperature.
Once the fondant has hardened, remove it from the mixing bowl by lifting the edges of the parchment paper. Place it onto a clean, flat surface.
Cut the fondant into small rectangular pieces that are suitable for feeding honey bees. You can use a knife or cookie cutters to shape the pieces as desired.
Place the cut fondant pieces into a rectangular baking dish or mold, ensuring that they are stacked neatly.
Cover the dish or mold with plastic wrap to protect the fondant from dust or contamination.