This is the brewing term for the process of extracting the goodness from specialty grains, crystal malt in this recipe. First pour 1/2 gallon of water from your 3 gallon water bottle and place a mark at the 2 1/2 gallon water level. Now pour up to 2 1/2 gallons of the remaining water into your brew pot leaving at least 3 inches to the top of the pot. Add your crushed grains. Turn on the heat to medium high and bring the temperature up to 150 to 155 degrees. Turn off the heat and cover the brew pot to let the magic take place inside for 30 minutes. Use a strainer to remove as much of the spent grain as possible without worrying too much about a few remaining grains.