If the head steward had asked where the wine came from, he would not have found the usual trail of evidence.
The amphorae in which the wine had been delivered
The broken seals on the amphorae
The sales record and receipt for the amphorae
The household inventory record for the amphorae
The name of the seller
And so on, and so on, all the usual evidence for wine with a past. Instead he would have asked the servants “Which wine was this, who did we buy it from?”, and they would have replied “It didn’t exist until about an hour ago; we saw it created miraculously”. There was no false appearance of age.