The key ingredients for a robust porter are the grains used in the recipe. Generally, you'll need a base malt such as domestic 2-row pale malt, which makes up 70-90% of the grain bill. In addition, dark grains such as chocolate malt and black patent are essential for achieving the desired flavor and color. Typically, 0.5 to 0.75 pounds of dark grain are used in a five-gallon batch.