Lime on Fish tastes Bitter I recently cooked tilapia in foil packets. I used Season All, and topped eached filet with guajillo salsa (flavored with lime) and lime slices.  I noticed a bitter aftertaste when I was eating the finished product.  It wasn't unbearable, but I didn't like it.  I'm thinking it was the lime slices.  I'm by no means a cooking pro, so I was wondering if anyone knows if lime slices add bitterness when cooked?  And if so, how to avoid?

My internet research didn't come up with anything definite.  (However, I discovered this website in the process!)
I'd be a little concerned about mixing aluminum foil with acid foods. Aluminum acetate has an astringent taste. I'm not finding it on the internet, but aluminum citrate (from citric acid in the lime juice) likely has a similar flavor.

Here's a recent, and seemingly reputable look at cooking acid foods in Aluminum foil (PDF file): Risk Assessment of Using Aluminum Foil in Food Preparation

Using parchment paper rather than aluminum foil would avoid the possibility of producing bad tasting metal salts.