I don’t get this one
My guess is at a certain point in popping corn in boiling oil, they throw watermelon juice on it (mostly water) and HOT grease and water mix in a violent way when combined with the natural gasses (O2, N, etc) causes - you know, just look up grease fires on youtube or your favorite alternative, like piped.
There’s a lot of sugar in watermelon juice. There was a dude in my dorms in undergrad who liked to take powdered sugar and make fireballs with it.
Powdered sugar burns so nicely because of the high surface area to volume ratio; watermelon burns like shit because it’s mostly water
Add to this that water vapor has 100x less density than liquid water. With 1 liter of liquid water, you can produce 100l, or 1m³ of vapor water.
So very hot oil + water, makes big fireball.
