Green Banana Gas

Bananas are a popular snack for Ultimate players, except when they are inedibly green.

With a little help from ethylene gas, a green banana turns yellow overnight. Ethylene gas is the odorless, colorless gas emitted when a fruit ripens. The gas is released in greater amounts from some fruits such as apples and bananas. Placing a green banana next to a ripe apple gives the banana exposure to a source of ethylene gas to quicken the ripening process. 

Step 1: Put the banana in the bottom of a brown paper bag.
Step 2: Put two ripe apples beside the banana in the bag.
Step 3: Fold over the top of the bag, closing it loosely to allow air to penetrate the bag while still trapping the ethylene gas. 
Step 4: Place the bag in an area that maintains room temperature out of direct sunlight.