Why are red apples sweet and green apples sour?
SR, I guess you haven’t tasted very many different varieties of apples! Apples are green before they ripen, and they are sour until they mature. Some varieties, such as Granny Smiths, stay tart, and some sweeten as they mature. But not all red apples are sweet. Pink Ladys, for example, are more tart than Yellow Delicious, or Red Delicious. My favorites are Galas and San Rose which are sightly tart, very crisp, and juicy. But for baking, you can’t beat Granny Smith and Northern Spy which are very crisp and very tart. But that doesn’t really answer your question! I’m not sure why the flavors are different, and why unripe apples are not sweet. I think it has something to do with how much acid they contain. I wonder what the chemical process is that causes them to sweeten as they ripen.
