From the brewery:

Vidal is a blend of 12 & 24 month oak aged mixed ferm saisons.  Each were brewed with malted barley, rye and raw & malted wheat.  Aged Jester and Goldings leaf in the boil and a mixed culture full of sach, brett and lactic acid producing bacteria.  

They were fermented in a stainless steel open top tank for 2 weeks then got transferred to freshly steamed and purged French oak barrels to undergo a slow secondary fermentation.  After extensive ageing and transformation including a slight amount of acidity creeping in the beers were ready to be blended with a very small dry hop of Saaz and Goldings briefly before being packaged.  They have been conditioning for 5 and a half months.