Gluten is a troublesome protein found in cereal grains such as barley, wheat, and rye.  Approximately 1% of the world population is affected by celiac disease which is an autoimmune disorder that damages the small intestine and affects nutrient absorption.  Gluten sensitivity is a recognised condition affecting about 6% of the US population, and involves other, less serious reactions from ingested gluten.  Since the primary source of sugar in brewing comes from cereal grains, most people with celiac disease and gluten intolerances avoid beer altogether, but craft brewers have gotten creative over the years in trying to offer gluten-free options that still taste great.  This post will introduce you to the basics of gluten-free brewing.