For each of the four cups at the Seder, it is preferable to use undiluted wine. However, if needed, the wine may be diluted with grape juice. (One who cannot drink wine may use grape juice alone.)
One drinks a cup of wine four times during the Seder:
- At the conclusion of kiddush.
- After telling the story of the Exodus from Egypt, before eating the matzah of Motzi Matzah.
- At the conclusion of the Grace After Meals.
- After reciting the Hallel.
It is preferable to drink the entire cup each time. However, it is sufficient to drink only the majority of each cup.
How large a cup should be used? One that contains at least 3½ fluid ounces.