Brew Source is a term used to describe the origin of beer. It is usually used to refer to the source of the ingredients used in the brewing process, such as hops, malt, and yeast. The term can also be used to refer to the location where the beer is brewed. The crossword solution for Brew Source is TAP, which stands for 'Total Alcohol Production'. This is a measure of the total amount of alcohol produced during the brewing process.