Summarize:

Use a pot that can hold the water so that it doesn’t overflow. Bring your water to a roiling boil with lots of bubbles. Be sure to watch your pot as you boil it to make sure it doesn’t boil over. Use a bowl big enough to hold all of your liquid ingredients, including the alcohol and cranberry juice later on. A metal mixing bowl is ideal, since boiling hot water could damage a plastic one.
Bring 3⁄4 cup (180 mL) of water to a boil. Pour the boiling water into a large metal mixing bowl.