* Online beer sites often indicate that this beer is made with Vitis Labrusca (Fox or Concorde) 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 of this is purportedly in barrels at Cantillon. No details about this batch are currently known, including what grape variety was used.
* Table grape must, such as what was provided to Cantillon for use in Don Quijote, is grapes from Itally are not permitted for use in wine and apparently cannot be exported from Italy. While this story cannot be confirmed, similar stories The origins of issues do exist <ref name=smuggling>Table Grape Must Cargo Seized in Italy, https://www.agra-net.net/agra/foodnews/raw-material/fresh-fruit/the grapes/table-grape-must-cargo-seized-used in-italy--1Don Quijote are unclear.htm</ref>
* There is a photograph of a different, white label Don Quijote bottle that is occasionally posted. All photos of this label appear to come from the same bottle and the legitimacy of this label cannot be confirmed. It is possibly something homemade or produced in small quantities, particularly since Umberto's Don Quijote bottles were apparently never labeled.