Q. When listening to Havdalah over grape juice, I make a silent stipulation that I am being yotzi with him, unless I decide later on to make my own. Later on, I may decide to repeat Havdalah on wine, especially if the person I heard did not properly articulate some of the words, or if I may have spaced out while listening, or perhaps he did not drink the shiur. Is this OK? Is there a preference of wine over grape juice?
A. Horav Shlomo Miller's Shlit'a opinion is that one may make a condition to be yotze with a later havdala, if it is then complied in a better way. The Rov maintains that the condition should be worded as saying; if one does recites later-on another havdala, that second one should take effect.
As far as choosing to recite a later havdala because of the preference of wine to grape juice, the Rov maintains that one should not repeat just because he now has wine available.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit'a