Mill the grains and mash in with 17 liters of 56°C water to reach about 52°C. Rest 10 minutes. First decoction: Pull one-fourth to one-third of the thickest part of the mash and bring that to a boil; boil for 10 minutes, then return it to the main mash to bring the total temperature to about 65°C. Rest 30 minutes. Second decoction: Pull another one-fourth to one-third of the mash for the second decoction and boil it for 10 minutes; return it to the main mash to bring the total temperature to about 70°C). Rest 30 minutes, then mash out at 78 °C for 10 minutes and sparge.