How important is it to fulfill the Beracha of בורא מאורי האש during Havdala? Is it a Chiyuv? The language of the Poskim: אם נזדמנה לו sounds like one is not obligated to seek out a Ner & fulfills Havdala even without a Ner. Is it enough that one person was reciting Havdala for the entire Yeshiva (Kehilla) and he enjoyed the Ner? I didn’t see the Ner, should I make a separate Beracha on a Ner? What about my wife and daughter – they too could not see the Ner. Should they make a separate בורא מאורי האש on a candle if there is no men to make the Beracha for them? They heard all of the Havdala but did not benefit from the Ner.
While the language of SHulchan Aruch implies this is not a chiyuv, the Chazon Ish [O:C 35:7] understans the leniency is not to expend efforts obtaining a Ner, but if one is available one is in fact obligated to make a bracha and benefit from the ner.
One who does not benefit does not fulfill this part of Havdala. If one was mafsik [interrupted] between hearing the bracha and benefiting, one should make this bracha when he has the opportunity [only on Saturday Night itself].
It is questionable if a woman is obligated in this bracha, as such she should hear it from another man. If this is not possible there are varying customs, it seems that the prevelant custom is to allow them to make the bracha on their own.
See Shmiras Shabbos Khilchisa Vol.2 Chapter 61:23-24.