In order to give the Brachos Yitzchok requested food from his son:
וַיָּבֵא לוֹ יַיִן וַיֵּשְׁתְּ
If he asked for food why did Yaakov bring wine?
According to Alshich, Yaakov was worried that Yitchak might notice that the dish he was served was actually goat meat, which is not an animal that one hunts, as Yitchak had told Eisav to. Therefore, Yaakov served wine with it in the hopes that with the taste of the wine mixed in, Yitzchak wouldn't pick up on the nuances of the taste of the meat he was eating.
Tirgum Yonathan to this pasuk: ".. and he didn't have wine, and a Malach came and gave him wine that was kept from the days of Bereshit Haolam (days of Creation?) and put it into Ya'akov's hand and he gave it to his father...".
A similar commentary we find in Da'at Zekenim Meba'alei Hatosafot. Here we learn that the Malach was Michael. They add that a similar situation was with Avraham and Malkitzedek in which the he brought wine and bread and blessed him.