Watch | Fascinating German beer making tradition using three ingredients

It's a tradition that goes back to the year 1516 - beer brewed using only hops, water and malt.Back then, it was the law.500 years ago, the purity law was decreed .”Germany's purity laws say that in beer only three ingredients are allowed to be present, hops, malt and water. At this time, yeast wasn't yet known about, but yeast of course also belongs there too”, says Martin Glaab, Andechs Monastery spokesperson. Yeast was later added to the list. While, the purity law is no longer the law of the land, brewing beer according to tradition is still an important part of Bavaria's culture. A monastery near Munich, Benedictine monks have been making beer according to the purity law for five centuries. Now, the monastery produces about 20 million bottles of beer every year- making it the biggest brewery in Germany.