un-do reverb

Hi, I have audacity 2.1.2, using a Zoom R8 as interface, windows 7 64bit. project is a multi trk song. I made a vocal trk, cleaned it up and then made a reverb and laid it on the trk. I closed the session and when I got up I listened to the vocal and decided that I need to take the reverb I made off the track, copy the track and AB different reverbs. I thought I could undo the orig reverb but that function closed when I ended the session. How do I undo the reverb so that I can rework this track? thanks: )

How do I undo the reverb

I don’t think you do.

UNDO vanishes when you close Audacity and Saving an Audacity Project doesn’t help. Projects don’t save UNDO.

I made a vocal trk

That’s supposed to say: I made a vocal track and exported a protection WAV copy.

Applying corrections, effects and filters over original work without a protection copy is a terrible idea because of the exact problem you’re having.