They drink the grapes juce or wine (grapes) to bless the God
Baruh Ata Adonai Eloheinu Meleh Laulam Asher Bore Pri Hagefen
Wine gladdens the heart (Psalms 104). While too much wine is a bane, the right amount has its benefits. It contributes to exuberance, gregariousness and expansiveness. Knowing this, Jewish tradition has included wine (in moderation) in many ceremonies; and the Shabbat meals are one of these occasions.
The blessings of the Havdalah ceremony mark the end of Shabbat.
Friday
At a shabbat service at your home or at a synogauge you may light the shabbat candles and say the shabbat blessings. Also some people follow it with hallah and/or a kiddush.
Candles, wine, and challah bread
Only in years where Yom Kippur happens to fall on Shabbat (Saturday). Otherwise, no.
During the havdalah ceremony, the person leading it recites special blessings over wine, spices, and a braided candle. The purpose of havdalah is to mark the end of Shabbat and separate the holy day from the rest of the week. The fragrant spices are included to revive the soul after the departure of the extra soul traditionally said to accompany Jews during Shabbat.
The blessing that ends the Jewish Shabbat is called "Havdalah." It marks the separation between the holy day of Shabbat and the rest of the week. During Havdalah, blessings are recited over wine, spices, and a multi-wicked candle.
The wine goes bad.
Shabbat ends on a Saturday night after nightfall. During that time Jewish people light havdalah candles and then dip them in wine to burn them out.
Shabbat dinner on Friday Evening is usually the most elaborate meal of the week. Observant Jews will light shabbat candles at home just before sunset, and begin the meal with kiddush, a special prayer and blessing over wine and bread. The bread is frequently challah, specially baked for Shabbat. If there is not a communal Shabbat kiddush luncheon in the synagogue, Shabbat lunch at home may be more ornate than the usual lunch, either with cold leftovers from dinner, or special dishes like cholent that are slow cooked overnight. At the end of Shabbat, there is a special prayer and ritual called Havdallah that divides Shabbat from the mundane days of the week. All of the Shabbat religious services can be held in the home for Jews who do not go to the synagogue for communal services.
The basic necessities for observing Shabbat are:Shabbat candles (at least 2) and an appropriate candle holder.Wine (grape juice is fine if you don't like wine) that is certified kosher.Two challot (plural of challah).Additionally, it's expected that we serve at least two different kinds of meat for the Shabbat dinner (Friday evening) [unless you are a vegetarian].And, as no cooking is allowed once Shabbat starts, many people use a slow cooker or Shabbat compliant oven (one that doesn't auto-shut off) to prepare a hot meal for lunch Shabbat day (Saturday) in advance.