Re: the soup smelled good what caused the odor?

Is the question, "what causes the smell of soup?"?

If so - basically, the odors one smells are from volatiles of the ingredients in the food. In this case, you can think of volatiles as chemicals that have a scent. Spices, for example, have very strong volatile odors - cinnamon, nutmeg, and black pepper are particularly notable. Fats in meat also have very volatile odors, particularly upon heating. That is why you can smell a steak cooking on a barbecue all the way down the block.

The components of the ingredients in the soup are responsible for the odor. The smell you probably associate with chicken soup are that of onion and chicken and maybe celery or bay leaves - and similarly, you probably can't smell the potato or carrots or peas in the soup. The heat causes the odors to travel farther (heat can transfer energy to the molecules and fling them farther through the air), and that's why you can smell them even when not in the kitchen.

As to whether or not the soup smells *good*, that is subjective. My mother's chicken soup contains green peppers, which I personally despise, so when I get a whiff of her chicken soup, I gag. However, the smell of beef stew makes me salivate like Pavlov's dogs.

-j.