Is there reason to believe that Jesus never actually drank fermented wine but only grape juice?
Answer: In the history of the Christian faith, certain taboos have risen to the surface. For many believers one of the worst is the consumption of alcohol. In their mind to do so is sin, pure and simple. And since Jesus never committed sin, the natural conclusion is that He never tasted fermented drink.
There's only one problem with that conclusion: it doesn't square with God's Word. Let's check our facts.
Fact number one: Drinking is nowhere condemned in the Word of God—only drunkenness. In fact, the Apostle Paul even counseled Timothy to "take a little wine" because of his stomach ailments. (1 Timothy 5:23) Notice Paul counseled "a little wine." He would never suggest that Timothy drink to excess because that was strictly forbidden for obvious reasons.* (See Ephesians 5:18) Sometimes potable water was hard to find, which made drinking other beverages necessary. Culturally wine was an accepted drink, although the dangers of over indulgence were known and certainly addressed in God's Word.
Fact number two: The first recorded miracle performed by our Lord in Cana of Galilee was turning water into wine for a wedding feast. (Believe me...they did not serve their guests grape juice at a wedding feast.) The belief that Jesus never tasted fermented drink is based on the presupposition that drinking in any amount is a sin. But since the Bible doesn't support that conclusion, there is absolutely no reason to believe Jesus never tasted fermented wine.
A Word of Caution to Believers
Now that I have addressed this question from a purely biblical standpoint, let me add a pastoral note. It is my considered opinion that believers today are altogether too casual about drinking and we need to prayerfully consider how our actions and attitudes may be affecting others.
And yes, I did say earlier that Jesus probably tasted fermented wine. But there's one important thing to keep in mind: YOU'RE NOT JESUS—and the chances of alcohol messing up your life are pretty good! So wisdom would tell you to steer clear of anything that has the potential of causing problems.
As a pastor I choose not to drink. Ever. Not because it's forbidden, but because it's not prudent. I have the freedom, but I choose not to exercise my freedom because 1) drinking has taken down much better men than myself, and I would be a fool to think I am above that sort of destructive potential, and 2) I have a responsibility to live my life in a manner that considers my weaker brother, for whom the sight of me drinking could possibly embolden to do the same, and so lead to his downfall.
As Paul said, “All things are lawful,” but not all things are helpful. “All things are lawful,” but not all things build up. 1 (Corinthians 10:23 ESV)
*The point needs to be strongly inserted here that if anyone cannot exercise self-control in the consumption of an alcoholic beverage, it is completely wrong for them to partake at all. As King Solomon wrote: "Wine is a mocker, strong drink a brawler, and whoever is led astray by it is not wise." (Proverbs 20:1 ESV)