Pumpernickel bread that came to be known as "Pumpernickel", Westphalian pumpernickel is distinguished by use of coarse rye meal and a very long baking period, which gives the bread its characteristic dark color. Like most traditional all-rye breads, pumpernickel is traditionally made with an acidic sourdough starter, which preserves dough structure by counteracting highly active rye amylases. That method is sometimes augmented or replaced in commercial baking by adding citric acid or lactic acid along with commercial yeast. Traditional German pumpernickel contains no coloring agents, instead relying on the Maillard reaction to produce its characteristic deep brown color, sweet, dark chocolate,
What Love Is Made Of three minutes and fifty-five seconds (3:55), "What Love Is Made Of" is an uptempo dance and house track that has been described as "rave-y" and "trance-y". Its instrumentation contains the sounds of pianos and synthesizers. Jordan Sargent of "Spin" observed that it continued the musical style first introduced in Katy's 2012 extended play (EP), "Danger EP", which was "straight-forward house". Idolator's Sam Lansky compared her performance in the song to recording artist Siobhán Donaghy. Critical response to "What Love Is Made Of" was generally positive: most critics noted Katy's vocal performance and commended its sound. Siân Rowe from "NME" was