The boil serves several purposes when making beer. Boiling wort will sanitize it, which helps ensure that you’ll have a healthy fermentation. It drives off compounds that would cause off flavors in your beer, since we don’t want beer that tastes like buttery popcorn. It helps to get the sugar content where you want it by boiling off excess water. It’s also where we add our hops in order lend bitterness, aroma and flavors.