The poskim discuss whether one may use grape juice for the Four Cups. Those that oppose the use of grape juise do so for the following three reasons:
1) The Gemara (Pesachim 108b) states, “Rav Yehuda says that [the wine used for the Four Cups] should have the taste and appearance of wine.” The Rashbam explains that when Rav Yehuda required that it have “the taste of wine”, he was referring to the alcoholic taste of wine. Accordingly, grape juice, which does not cause intoxication would not qualify as most preferable.
2) According to some authorites, including the Mordechai and Harav Chaim Shabsai, one must drink ,”יין המשמח” wine that brings joy. The poskim explain that the property of wine that causes it to “bring joy” is the alcohol. Therefore, argues Harav Tzvi Pesach Frank zt”l one should not use grape juice for the Four Cups since it does not “bring joy”. (See Mekraei Kodesh Pesach vol. 2 page 130)
3) The Gemara (Pesachim 108b) states that one who drinks wine [of the time of the Gemara] without diluting it fulfills the mitzvah of drinking wine, but does not fulfill the requirement of “חירות”, the drink of free men. The opinion of Harav Moshe Feinstein zt”l is that one who drinks grape juice fulfills the requirement for the Four Cups, but does not fulfill the preferred requirement of חירות. As Harav David Feinstein shlit”a writes (Kol Dodi 3:4), “Also, the principle of ‘demonstrating freedom’ in our performance of the Seder ritual plainly remains unfulfilled with such wine. Moreover, it is for this reason that the Gemara faults undiluted wine in Talmudic times when it was customary to dilute wine with water, the Gemara faults undiluted wine for this reason. Since ‘demonstrating freedom’ means fulfilling the mitzvah in its most preferable manner (Rashi and Rashbam), my father and master, (Rav Moshe Feinstein) zt”l, ruled that one does not fulfill the principle of ‘demonstrating freedom’ with grape juice.
Harav Shlomo Zalman Braun zt”l, however, disagrees with the assertion of Harav Moshe Feinstein zt”l. He writes that the common custom is to drink grape juice for the Four Cups. He adds that one demonstrates freedom by drinking the wine drink that is the most pleasant to you. If one prefers grape juice over wine, then he should drink grape juice as that is what a free man would do. On the contrary, drinking wine when it is unpleasant is, in his opinion, is not a fulfillment of the preferred requirement of חירות (Shearim Metzuyanim Behalacha 118:1)
Harav Yosef Dov Soloveitchik zt”l likewise believes that one who does not enjoy wine should use grape juice for the Four Cups. He expalins that drinking undiluted wine is uncommon and unpleasant (due to the high alcohol content) and it is for this reason that one does not fulfill the requirement of דרך חירות. However, drinking grape juice is quite pleasant and would therefore qualify as דרך חירות. Moreover, he notes that the Rambam explains that we require wine for the Four Cups to be diluted “in order that the drinking of the wine should be pleasant, all according to the wine and the taste of the consumer.” We see from the Rambam that the beverage consumed for the Four Cups should be pleasant for the consumer. Therefore, concludes Rav Soloveitichik, if one does not enjoy wine, he should use grape juice for the Four Cups, as that will be a pleasant drink according to his taste. (Oral ruling cited by Rabbi Menachem Genack shlit”a Mesorah 12) Harav Shlomo Zalman Auerbach zt”l (Hebrew Haggadah page 96) was also of the opinion that one may use grape juice for the Four Cups.
Similarly, Rav Moshe Sternbuch shlit”a (Teshuvos V’Hanhagos 2:243) relates that Rav Dov Berish Weidenfeld zt”l (the Tchebiner Rav), the Brisker Rav and the Chazon Ish all used grape juice for the Four Cups. Harav Gavriel Zinner shlit”a (Pesach vol. 2 Chapter 71:6) also writes that according to the Tzelemer Rav, grape juice is acceptable even l’chatchilah [as a first option]. For practical Halacha, a rav should be consulted.191