Machlokes Rishonim
23. In the production of wine and grape juice, some companies cook the wine or grape juice by boiling it. There are multiple reasons they do this: either to stop fermentation; to avoid concerns of yayin nesech in case of contact with a non-Jew, as cooked wine is not subject to the issur; or for other reasons. There is a machlokes haposkim about the status for Kiddush.
24. Some Rishonim hold one should not make Kiddush on cooked wine since cooked wine is not fit for nesachim on the Mizbeiach (פכ''ט רמב''ם הי''ד, תשב''ץ ח''א סי' פ''ה ושו''ת רדב''ז סי' של''ה בדעת הרמב''ם, שו''ת הרי''ף סי' רצ''ה, שו''ת רש''י סי' פ''ח). Some hold this is true even if the wine is not negatively affected (חי' הגרי''ז מנחות דף נ''ז ע''ב). Some say the reason is because it is altered from its natural state (רי''ץ גאות בשם רב האי גאון הל' קידוש ע''ג).
25. However, most Rishonim hold one may make Kiddush on cooked wine (תוס' פסחים דף ק''ט ע''ב ד''ה ארבעה, ר''ת הובא ברא''ש ב''ב פ''ו סי' י', רמב''ן ב''ב דף צ''ז ע''ב ד''ה למעוטי, רשב''א ב''ב שם ובשו''ת ח''א סי' כ''ד, ריטב''א שם).
26. In practice. The Mechaber cites without attribution the opinion that allows making Kiddush on cooked wine (שו''ע סי' ער''ב ס''ח) and then cites the machmir opinion as a “יש אומרים.” The Rama concludes the minhag is to be meikel and make Kiddush on cooked wine (רמ''א שם).
27. Two wines available. However, if one has two wines of equal quality in front of him, one cooked and one uncooked, he should give preference to the uncooked one to satisfy the machmir opinion (מ''ב סקכ''ג). Even if the uncooked wine is good but the cooked wine is better, preference should be given to the uncooked wine (א''ר בשם האגודה).
