Complex sentence: Originally, Tsingtao Beer was brewed in accordance with the German "Reinheitsgebot" ('Purity Law') of 1516, therefore the only ingredients that were used were water, barley, and hops.
Split into simpler sentences: Originally, Tsingtao Beer was brewed in accordance with the German "Reinheitsgebot" ("Purity Law") of 1516. Therefore, the only ingredients that were used were water, barley, and hops.