Do you make kiddush on Friday night with wine or with grape juice? Is your wine red or white?
The Gemara on today’s daf brings Rabbi Zutra bar Toviyya who quotes Rav as teaching that only wine that could be used as a libation on the altar in the Temple can be used for kiddush. At first, the Gemara assumes that this statement comes to exclude yayin mi-gito – literally “wine from the press,” or grape juice. This supposition is rejected by the Gemara, which quotes Rabbi Hiyya as teaching that if used for libation, such wine will be acceptable on the altar, at least ex-post facto. In fact, regarding kiddush, the Gemara quotes Rava as teaching that someone can squeeze a bunch of grapes into his cup and use it for kiddush.
Several other suggestions are raised in an attempt to identify the wine that will not be appropriate for kiddush given that it cannot be used for libation in the Temple, all of which are wines that are considered of lower quality, e.g. yayin kushi – black wine. Sometimes, when wine was stored in iron casks, or even if there was a high concentration of iron in the ground where the grapes were grown, the small amounts of iron oxide (Fe2O3) together with the natural tannin in the wine can oxidize, which turns the wine bluish, and eventually black as ink. Although this does not affect the taste of the wine, it is considered to be of lower quality.
The conclusion of the Gemara seems to be that white wine could not be used, although it is not clear whether the Gemara is referring to libation or to kiddush. This leads to differences of opinion regarding the halakha, with the Ramban rejecting the use of white wine for kiddush, and others suggesting that if possible it should not be used. Rabbeinu Yona, however, permits its use for kiddush, arguing that in some places white wines are considered to be finer than their red counterparts.