When one recites Kiddush on wine, one must take a cup which holds a Revi’it (81 cc or approximately 2.8 fluid ounces) of wine. The cup must then be washed both inside and outside. One must then fill the cup with wine that is acceptable to bless on, i.e. wine that has not been drunk from already. However, if this wine has already been drunk from in the same vessel it has been inside until now, such as if one has drunk directly out of the bottle the wine was stored in, this wine has become unfit for Kiddush.
One must then grasp the cup in one’s right hand and raise the cup a Tefach (8 centimeters or approximately 3 inches) or more from the table; one’s left hand should not assist one’s right hand in doing so. One should then proceed to recite the text of the Kiddush and then be seated and drink at least a majority of a Revi’it (approximately 44 cc or 1.5 fluid ounces) of the wine. The rest of the individuals seated around the table should taste some of the wine in order to endear the Mitzvah.
The reason why we stand during Kiddush of Shabbat night is in honor of Hashem Whom we are considered going out to greet. Additionally, reciting “Vaychulu Ha’Shamayim Ve’Ha’aretz” is tantamount to offering testimony to the creation of the world by Hashem and when a witness gives testimony, he must stand.
Nevertheless, according to the Rama and the Ashkenazi custom, Kiddush is recited while seated and only before beginning does one rise slightly in honor of Hashem. Although it is certainly preferable to remain standing during the entire Kiddush as is the Sephardic custom, nevertheless, the Kol Bo writes that one should sit during Kiddush, for the rule is that Kiddush may only be recited when a meal will follow the Kiddush; thus, it is proper to sit close to the table one will soon begin eating one’s meal on. (We shall, G-d-willing, discuss this law of Kiddush in a place where one will eat his meal in the next Halacha.) On the other hand, Maran Ha’Bet Yosef dismisses the Kol Bo’s opinion on this matter and rules that one must stand during Kiddush. The saintly Ari z”l rules likewise and this is indeed the Sephardic custom.
One may only recite Kiddush on wine whose blessing is “Boreh Peri Ha’Gefen.” We have already mentioned in the laws of Pesach that some of the wines and grape juices sold on the market today are not “Boreh Peri Ha’Gefen” according to Maran Ha’Shulchan Aruch, for they are heavily diluted with water and other flavoring agents. We have likewise mentioned that one should not rely on all Kashrut supervisions in this regard even if they claim that the wine’s blessing is “Boreh Peri Ha’Gefen” even according to the opinion of Maran Ha’Bet Yosef. One must therefore take care to purchase wine or grape juice from a company that is known to produce its wines from actual grape juice (and diluted only with a minority of water and other flavors, if any).