Don't tease us. What's the trick?
first you take the egg, then you consume it, now wait somewhere between 2 - 12 hours to see how good the egg was, if you get bad farts then the egg was fine, if the farts are accompanied by brown/green liquid then the egg was bad.
Fancy hearing me on an amateur podcast with friends gushing over one of my favourite games? https://youtu.be/1I7JfMMxhf8