Bottles should be free of liquid, but rinsing is not necessary for recycling. Keep in mind, however, that even though plastic recyclers support including caps and are able to process the material, you should always follow the instructions of your local recycling program.

Should caps be left on plastic bottles when recycling?

It's important that you remove lids and throw them out before tossing the plastic container in the recycling bin. ... They usually have a higher melting point and can ruin the entire load of plastic that is trying to be recycled. Remember to always unscrew the lid or cap from your plastic containers before recycling.

What is the proper way to recycle plastic bottles?

When recycling plastic bottles, check to see if they say "crush to conserve" on the label. If so, remove the lid and crush the bottle by twisting from the top and pressing it down. After it's crushed, place the lid back on the bottle so it can also be recycled.