Application cookie value

Recently we cloned our PROD environment back into TEST, and were going through the checklist to reintegrate everything when we encountered a problem.  The cookie value for the application was still showing PROD, even though we had cloned it onto the TEST database so we knew it had to be some type of configuration value but we didn't know exactly what it was.  Doing a quick search of the profile options showed that the value for "Applications Database ID" had the PROD database name in it which isn't the way it should be in TEST!  We changed it to what it should be for TEST, but nothing changed so we bounced Apache and then we had the correct cookie value being returned!