Lemonnades

Creation
Aperture brand Combustible Lemons, or "lemonnades", are a technology developed by the ghost of Cave Johnson. They were originally concieved because of some insane rant about Twilight fans and the cancellation of Foster's Home for Imaginary Friends, but then after eating Ratman's remains he had nothing better to do then perfect the technology and test it on the Companion Cube, which, of course, is fully sentient and feels 3.2 times as much pain as the average human. When he escaped the facility, however, he used them for random acts of anarchy and brony hunting.

Usage in Minecraft
In 1994, Cave found a portal leading to a certain Minecraft world. There, he lived off of raw bacon and wolves, which feel .94 times as much pain as the average Irken.

One day, he came across a crudely built house. When he took a closer look, he realized it was built by Scout, who had entered the Realm of All That is Pixelated due to a rather painful incident involving Jarate, Crit-A-Cola, and a hamster, which feels absolutely no pain (at least, it rounds down to zero). Due to Cave's insanity, he mistook Scout for life and burnt his house down. He was then killed by Cherry, who is a very, VERY bad demoman.

Modern Usage
You're kidding, right? Nobody uses lemonnades anymore. They smell like burnt lemons, unlike their counterpart: Morshu's bombs.