Step 4: Cook
-to kill any bacteria in your apple juice that might contaminate your brew
-to kill naturally occurring wild yeast
NOTE: If you want to do this old school, you can skip pasteurization and just put it in your carboy and let the wild yeast ferment it, but this will probably take a lot longer and might taste a bit off.
Put your cider in a big stock pot over medium heat and allow it to cook for about 45 minutes, stirring regularly with a metal or sanitary plastic spoon. DO NOT ALLOW IT TO BOIL!!! The temperature should be kept just below boiling at all times. If you allow it to boil your cider will become cloudy and never fully settle.
You can add the 2 cups of brown and white sugar here if you'd like. This will raise your alcohol content and make a slightly sweeter final product, but it is not absolutely necessary.
When the cider has cooked for 45 minutes, allow it to cook. Meanwhile, you should sanitize your carboy by adding half a cap-full of bleach to a gallon of water and allowing it to stand for half an hour. Then rinse thoroughly with cold water.
Once the cider has cooled to room temperature, poor it into your carboy leaving a few inches of room at the top for the yeast (if you have too much, just drink it! mmmm, warm cider!)
NOTE: I mentioned Campden Tablets earlier. If you chose to use this method you should not cook your cider. Basically what these tablets do is create a chemical gas in your cider that will naturally sanitize it and kill all the yeast. I have never used this method, though a lot of people prefer it because cooking does not always kill all of the yeast and you tend to lose some of the aromatics when you pasteurize with heat. If you want to use this method, I recommend you research it further, as I am not overly familiar with it.