According to those (Rav on some occasions) who would wash and make Kiddush on pas, what happened to the 'apparent' - chiyuv, 'zochreihu' to be mekadesh al hayayin ?
Sholem, UK
Sholom Rav.
Bearing in mind that, as Tosfos explains, whereas Kidush is d'Oraysa, Kidush al ha'Kos is only an Asmachta, it seems that, on the one hand, like Sheva B'rachos and Havdalah, Chazal fixed Kidush over wine. On the other hand, since we have a principle 'Ein Kidush Ela be'Makom Se'udah' - and the Ikar Se'udah is Pas, where there is no wine one can makes Kidush over Pas, and what's more, if someone is hungry, then Pas even takes precedence over wine.
Interestingly, even when making Kidush over wine, one of the reasons we cover the Chalos Is because Chalos ought to take precedence over wine - because 'Chitah' is mentioned before 'Gefen' in the Shiv'as ha'Minim.
With best wishes for a Chag Kasher ve'Same'ach.
Eliezer Chrysler