Jacob then summoned the rest of his sons and blessed each one in accordance with his unique contribution to the overall Divine mission of the Jewish people. These individual emphases became the defining characteristics of the 12 tribes that descended from them. In his blessing to Judah, Jacob said that Judah’s portion of the Land of Israel will be so suited to growing grapes that he will be able to wash his clothes in wine.
The Torah's Inner Dimension
כִּבֵּס בַּיַּיִן לְבֻשׁוֹ וגו': (בראשית מט:יא)
He will launder his clothes in wine. Genesis 49:11

Every time we observe a commandment, we create a spiritual “garment” for our souls. These garments, however, must be “laundered in wine” – our fulfillment of the commandments must be imbued with joy.

The way to achieve this joy is by studying the inner dimension of the Torah – the teachings of Jewish mysticism (Kabbalah and Chassidism) – for this dimension of the Torah inspires us to love G‑d and cleave to Him through observance of His commandments. It is for this reason that this aspect of the Torah is referred to as “the wine of Torah.”1