<<Disclaimer:  Verify this information before applying it to your situation.>>

J.A. Campbell, Ph.D, Ottawa writes that spirits now are distilled in column
stills containing 20 or more perforated plates in each column.  Steam rises
through the columns stripping the alcohol from fermented mash.  Alcohol
vaporizes at 78.5 degrees C but gluten or gluten fragments are not vaporized
and do not go through the still.  In the case of gin, vodka and the major
components of Canadian whisky blends, the base spirit is redistilled through
a multicolumn still with three to five columns to remove fusel oil and other
impurities.  This redistillation step further reduces the possibility of
protein carryover into the final product.  It is concluded that distilled
beverages, fortified wines, white distilled vinegar and alcohol based drug
and extract products do not contain measurable amounts of gluten or gluten
residues and therefore must be considered acceptable for a gluten-free diet.
 It goes on and on, but I no longer use alcohol free vanilla, and do use
distilled vinegar (my 6 year old hasn't asked for a cocktail yet!).  This
information was presented at a meeting of the Celiac Disease Foundation in
Los Angeles a couple of years ago by guest speaker Don Kasarda.