Biochemical methane potential (BMP) tests are widely used for characterizing a substrate’s influence on the anaerobic digestion process. As of 2018, there continues to be a lack of standardization of units and techniques, which impacts the comparability and validity of BMP results. However, BMP methods continue to evolve, and key aspects are studied to further eliminate systematic errors. This paper aims to update these key aspects with the latest research progress both to introduce the importance of each variable to those new to BMP measurements and to show the complexity required to design an accurate BMP test.