Using the metaphor of waiting for the primordial soup to boil seemed like a good way to show how slow the process could have been. Of course, once it hits that tipping point it explodes into life and starts to violently boil over. It’s kind of like the hot break when you’re brewing beer, which is something I had started doing about the time I was illustrating this page. At this point you’ve added the grain extracts and you’re bringing the wort to a boil, and if you’re not careful it will bubble over and make a huge mess. If you watch it carefully you can turn off the heat when it starts foaming up, and then when you add the bittering hops it seems to prevent it from bubbling up any more.