@J12t if you haven't done much work with candy or sugar in general the process can be a bit vague. Usually up to waters boiling point (depending on your altitude) the temperature rise is quite fast. After the water starts boiling the only way for it to get hotter is by boiling off water and having a higher sugar to water ratio. This can take a long time and this ratio is the only thing that affects the temperature, since you can never be hotter than the boiling point of your liquid.