Minecraft wiki entry for Defeating_a_Nether_fortress, associated text: Use one blaze rod to craft a brewing stand, and then craft the other into blaze powder. Take a look into the brewing stand GUI if you haven't already. There are three slots for bottles, an unmarked slot for ingredients, a blaze powder shaped slot, an indicator for fuel, and an indicator for progress on your currently brewing potions. Drop a blaze powder in the blaze powder slot, it should disappear and the fuel indicator will go solid orange. This fuel gets depleted once for every 20-sec operation you do, and a blaze powder has 20 'charges'. Be sure to kill some more blazes later on for more powder to fuel your brewing stand.