There are a variety of unknowns related to this beer:
* Online beer sites often indicate that this beer is made with Vitis Labrusca (Fox or Concord) Grapes. This is an American grape variety and while they do grow in Europe, it's not clear if that is the grape that was actually used.
* A second Don Quijote batch is purportedly in barrels at Cantillon. No details about this batch are currently knownhas been discussed, including what grape variety was used.potentially for [[Zwanze_Day|Zwanze Day]]
* Table grapes from Italy are not permitted for use in wine and cannot be exported. The origins of the grapes used in Don Quijote are unclear but are rumored to come from the countryside near the Goblin pub.
* There is a photograph of a different, white label on a Don Quijote bottle that occasionally appears online. All photos of this label appear to come from the same bottle and the legitimacy of this label cannot be confirmed. It is possibly a homemade or limited run label, particularly as Umberto's Don Quijote bottles were never formally labeled.