Answer:
When young I am sweet in the sun. When middle-aged I make you gay. When old I am valued more than ever.
I am a word. I become longer when the third letter is removed.
I was not born but I am here. I have no name but I am given many. I was made by science and life
I am always around you but often forgotten. I am pure and clean most time but occasionally rotten.
I wonβt break if you throw me off from the highest building but I will break if you place me in the ocean.
The warmer I am the fresher I am.