When buying blueberries these are the main things you need to remember:
1. Blueberries should be blue. If they are red or purple, then pass on them.
2. The blueberries in the package should all be about the size (not all different sizes) and they should come with a waxy sheen.
3. You should keep blueberries refriderated and dry. If you do this they can last about 2 weeks. If you don’t, they will spoil fast. Don’t wash blueberries until you’re ready to eat them.
4. When you see stains on the plastic packaging, blueberries have gone bad. It’s time to throw them out.