Electrolytic Capacitors damaged while Soldering
PROBABLY OK but cannot be sure.
 If this is mission critical / life support / you really care, then replace it.
If it failing is no big deal then leave it and see.
 In many cases it will be OK.



A modern "electrolytic capacitor" (usually an Aluminum wet electrolytic capacitor)is built inside an Aluminum can which serves as the negative connection. The outer plastic layer has no part in the operation of the actual capacitor - it serves as a means of insulating the can from accidental electrical contact and provides a convenient place to write information on.  If you destroy the plastic that does not affect the capacitor in any way BUT heating the metal can will transfer some heat into the interior. A mild 'touch' is liable to have little or no ill effect but any strong localised heating may boil local electrolyte or cause damage through expansion of the material. 

Experience suggests that there is enough heat-sinking in the can to allow the occasional light touch with no perceived ill effects in normal use. BUT ANY touch that causes significant heating MAY cause problems months or years later. If you care or it matters, and it was not an expensive capacitor, replace it. If not replaced, keep a small mental note for the future - and learn to solder even more carefully :-).