““The Holy Grail is a pet food that not only smells unobjectionable, but also makes the pets’ feces smell unobjectionable. It’s a challenge because most things you could add to do that will get broken down in digestion and rendered ineffectual. Activated charcoal is problematic because it binds up not just smelly compounds, but nutrients too. Hill’s Pet Nutrition experimented with adding ginger. It worked well enough for a patent to have been granted, which must have been some consolation to the nine human panelists tasked with “detecting differences in intensity of the stool odor by sniffing the odor through a port.””