Second edition of the e-book "Principles of Beer Production and Enzymes in Mashing" (2024), with revised and improved content, as well as new photos, mashing enzymes, and commercial enzymes. This e-book presents an overview of beer production and the ingredients used, contextualizing the mashing stage, which is discussed in detail. Mashing is one of the main steps in the hot (initial) phase of beer production, involving the extraction and transformation of molecules present in malts and other brewing ingredients to produce the wort that will be fermented to create the beverage. During mashing, depending on the procedures adopted, various enzymes may act, each with different optimal substrates, temperatures, and pH levels. Thus, understanding the enzymes present, how they work, and their consequences for production is of utmost importance. To this end, the main enzymes are presented, relating them to the possible outcomes in the wort and the final beverage. It is hoped that reading this e-book will help you understand the importance and actions of the enzymes present in mashing, assisting you in the conscious planning of this crucial stage involved in beer production.