I Follow the sugar and water measurements exactly, swirl the pan and brush the sides, and it still tends to crystallize. What am I doing wrong?
Couple of things to try: make sure the water is covering the sugar when you start out. I don't stir or swirl; I just let it come to a boil and brush down the sides. The swirling should begin when you start to see a light golden color begin to form. the swirling helps the sugar turn color evenly. Do it gently. I also find that a copper pot or a heavy bottom, medium pot works best.
You could also add a small amount of cream of tartar or lemon juice to "invert" some of the sucrose so it's a bit less prone to crystallization.
If you add cream of tartar, be sure to dilute it with an equal amount of water before adding it. It is an acid, and has the effect of causing like poles of sugar to spin around towards each other, much like trying to force like poles of 2 magnets together, and thereby inhibiting re-crystalization. Alternatively, add a bit of corn syrup or honey, which are already invert sugars, and which already contain a small amount of acid to keep them that way. The amount is proportional to the amount of caramel you're making, but a couple of ounces should do the trick for you.
Thank you everyone. I kept my very heavy pot on med low, but I have a huge stove, could it have been too hot?
No, I doubt heat was the problem.