At Billy's house

Jennifer: What in the world is that smell?
Billy: The aroma of roasting coffee beans.
Jennifer: Smells like you're baking something. What are those?
Billy: Green beans. They pop and turn brown when you roast them.
Jennifer: Cool! But isn't that a hot air popcorn popper?
Billy: This machine roasts the beans just right. If you roast them too long, or the temperature is too hot...
Jennifer: The beans will burn. I know. I've tasted burnt coffee before...yuck!

aroma (n.) 　
香味

roast (v.) 　
烘焙；bake (v.) 烤。这两个字的差别在于bake是将食物放在烤箱中烘烤，而roast除了表示放在烤箱里烤，也可以是放在火上烤

pop (v.) 　
爆开

popcorn popper 　
爆制爆米花的机器

temperature (n.) 　
温度

在比利家

珍妮花：那是啥味道？
比　利：烘焙咖啡豆的香味。
珍妮花：闻味道还以为是你在烤什么东西吃。这些是啥？
比　利：生咖啡豆。当你烘焙它们的时候，它们就会爆开，并转成棕色。
珍妮花：酷！但那不是一台爆米花机吗？
比　利：用这机器来烘焙咖啡豆正好。要是烘焙过久，或是温度太高……
珍妮花：那么咖啡豆就会焦掉。我知道。我有喝过煮焦的咖啡……恶！