Raymond Brown's Anchor Bible commentary on John situates Cana as the first of the seven signs that organize the gospel's first half, the section scholars call the Book of Signs, and reads its details, the stone jars used for purification, the abundance and the quality of the wine, as deliberately symbolic: Jesus is presented as superseding the old rites with something new and overflowing. Brown treats that symbolic shaping as compatible with, but not proof of, an underlying historical occasion.
Because the story is absent from Matthew, Mark and Luke and is woven tightly into John's own theological pattern, historical-critical scholars are divided on how much, if any, historical incident underlies it. Some read it as an early tradition John inherited and shaped to fit his sign structure. Others read it as a Johannine composition with no independent historical core, built to make a theological point about Jesus at the outset of the gospel rather than to report an event. Unlike some other miracle claims, no naturalistic mechanism, a substitution of wine, a trick of lighting, has significant scholarly currency here; the debate is about the story's literary origin, not about how the described transformation might have been achieved by ordinary means.