Ok, sparging isn't quite that exciting. In this step, water in the top tank (Hot Liquor Tank, or HLT) is heated up to 175 degrees. This is slowly gravity fed down into the same contraption seen in the previous set of pictures where the mash was reciruclated. At the same time, the wort is slowly pumped over to the boil kettle. The goal is to maintain a consistent level of liquid in the mash tun, so that there is always a layer of hot water over the grain bed. This stops the process that the grains were undergoing to convert enzymes into sugars. The influx of hot water also serves to wash these sugars from the grain and get as much of it as possible into the boil kettle.