What is k ey lime juice?

Well said littleknitter, thanks for sharing your knowledge!

Key lime juice is from key limes which are smaller and sweeter than regular limes. You can sometimes buy whole key limes and then juice them yourself, but you can also buy key lime juice in a bottle. Start with Whole Foods, if there is one near you, then try Trader Joe's. Ethnic grocery stores like West Indian or Asian stores might have them. If you can't find key limes, you can substitute a mixture of regular lime juice and lemon juice.