Why do we make the non-havdalah Brachos at havdalah if they're not necessary for the mitzvah?

Question

As discussed here, not having spices or a flame does not prevent one from doing havdalah.

All of them have their reasons for being a part of the service (see this Aish article, point #5, for those reasons), but they all seemingly have nothing to do with havdalah so much as the exiting of Shabbos in general. In light of that, why don't we just make the havdalah brachah and say the other Brachos at some other point during the night? Is it just for convenience, that since we're sitting down to do this mitzvah, we might as well do the others also, or is there some deeper reason that they should be done together?

Answer 1

The Aish link you brought is very good in setting the tone for what you know and want to find out, so thank you.

In regards to borei moreih ha'esh, the Gemara brings the idea of waiting to say the bracha contrary to saying it right away just as a minhag, not too much reasoning there (see Pesachim 54a, R' Yehuda holds and R' Yochanan says halacha is like him-R' Yochanan usually the authoritative Tanna as far as psak from Gemara goes and we see that follow through for Rambam Hil Shabbas 29:24 and Tur Shulchan Aruch 296:1)

In Shulchan Aruch, the Rema notes the minhag of pouring the wine first as a sign of a bracha (for the week) and specifically over the meorei haesh-- no reasoning.) The first reasoning that I found was is in the same siman of the Shulchan Aruch HaRav (Seif 5) quoting the Levush (271:10) that pouring the wine to put out the candle signifies the candle's use specifically for the mitzvah of havdalah and brings in the name of the Rema (mentioned earlier) that we rub our eyes with the wine to signify our enjoyment of and love for the mitzvah.

Seemingly this wouldn't be an opportunity without the candle for the wine but my Rosh yeshiva said this wasn't the reason, just the way the minhag is fulfilled through the meorei ha'esh and bsamim being a part of Havdalah. He further mentioned that it's logical (and potentially why it's hard to find mefarshim say so explicitly) that in general, saying something over wine in Yiddishkite signifies an importance ceremonial emphasis of kedusha as we see it used for kiddush/Havdalah for Shabbas and festivals, kidushin of the chupah, Birkas hamazon with a zimun. It in a sense anchors down the mitzvah in a mehudar way so how much more so when you anchor the two other related brachos related to Motzei Shabbas.

Fun practical minhag some have as an outcome of saying all three brachos together is the ability to light the candles required for melaveh malka (as in Kittzur Shulchan Aruch 96:12) with the Havdalah torch before putting it out with wine. Hopes this helps.