When we moved back to Hazelton from High Level in the late 80s, Dad had a job teaching at the alternate school in 2-Mile. He was one of two teachers, the other was the admin, and the small school was basically split in half between them. He would have been around 32 years old. He got a homemade root beer making kit from somewhere, collected up some used 2 litres, and got to making root beer as an educational activity.
Here on the farm the boys and I have made our first forays into fermenting food. I've learned that naturally fermented food creates carbon dioxide, and if you limit it to a sealed bottle, that carbon dioxide dissolves into the liquid as the pressure in the bottle increases. Experienced brewers will put the fermented brew into the bottles at just the right time, so that the pressure isn't so high that it will explode the bottle. Dad was not an experienced brewer. At all.
Normally when you open a carbonated drink - like a can of beer or pop - there's a little hiss as the extra pressure escapes, then you can go ahead and enjoy the fizzy drink. Something went a bit wrong with Dad's brew, because the 2-litre bottles became *extremely* pressurized. I looked it up, and modern plastic 2 litres max out around 150 PSI - to compare, your car tire probably has around 35 PSI in it. When you opened one of Dad's homemade root beer bottles, you had to hang on for dear life. It must have been up around the limit of the bottle.
Dad absolutely DELIGHTED in the difficulty and drama of opening his homemade root beer. He'd devised a method where the 2 litre would sit in a big mixing bowl. One person would unscrew the lid, while another would hold a large measuring cup (4 cups or larger), facing down, over top. As the cap came off, all the pressurized homemade pop would explode out the bottle, and shoot upward with incredible force. The person holding the measuring cup would need to keep a death grip until the bottle depressurized. The rocket stream of pop would hit the inside of the measuring cup, and flow back down into the mixing bowl. Afterward most of the pop would be in the mixing bowl, and a small amount would be left in the bottle. To get a rough idea of what this is like, check out Mentos + Coke fun.
Dad's favourite story was when he first brought the "finished" brew into school, and had the students help him open it. He had a student holding the measuring cup while the cap was unscrewed. When the pop exploded out and hit the measuring cup, the student screamed, let go, and ran away. By his telling, the force was so strong that it blasted the large measuring cup all the way up to the ceiling. The root beer mushroomed against the ceiling before calming down. He would proudly proclaim that the root beer stain is still on the ceiling of the alternate school to this day - and to the best of my knowledge, it still is! The last time I was in there a number of years ago, I was able to find the stain quite easily, and it was quite large - larger than a dinner plate.
Unfortunately I don't recall Dad attempting any more home brew after that, other than some strange miracle mushroom ferment, but that is another story. The exploding root beer at school was one of his many favourite stories to tell.