I was raised Mormon and this was the excuse they used. They have to lie and make shit up to keep things consistent.
Throughout the passage, the Greek word translated “wine” is oinos, which was the common Greek word for normal wine, wine that was fermented/alcoholic. The Greek word for the wine Jesus created is the same word for the wine the wedding feast ran out of. The Greek word for the wine Jesus created is also the same word that is used in Ephesians 5:18, “…do not get drunk on wine…” Obviously, getting drunk from drinking wine requires the presence of alcohol. Everything, from the context of a wedding feast, to the usage of oinos in 1st century Greek literature (in the New Testament and outside the New Testament), argues for the wine that Jesus created to be normal, ordinary wine, containing alcohol. There is simply no solid historical, cultural, exegetical, contextual, or lexical reason to understand it to have been grape juice.