If it’s an extract beer, it will generally have less foam because the extract has less proteins in it, which are the key to foam. Hoppier beers have better foam because the polyphenols in the hops bind the proteins in the beer and produce better foam. Finally, yeast pitching rate, health, and fermentation temp play a big role. See http://byo.com/stories/article/indices/ … techniques . It also contains some tests you can do to help determine what the issue might be. Some people will tell you to add protein heavy ingredients, like carapils, or flaked wheat or barley. Those will only help if you don’t have the other problems listed in the article I linked.