Continuing with medium heat, wait for the mixture to start to bubble, then turn it down. The mixture will start bubbling almost immediately, so don't walk away, otherwise the ingredients may burn. Once you see the syrup bubbling, turn the heat down to low and cook, stirring often, for 15-17 minutes. After that time, pour the pecans onto a plate lined with tin foil. Using a fork, spoon, or spatula, gently separate the pecans into a single layer, otherwise you'll have a big pile of pecans stuck to each other. Set aside and let cool.