Ok, this is only the "theory"
according to many bottles examined by my friends and me.
before 1994/5 : simply check the bar-code (missing or not?) on the box. If the bar-code is missing, it's most likely before those years. Not too exhaustive, but enough to state it's vintage.
Since 1994/5 to 2004/5: 4-number batch code on box (on the bottom of the bottle you will find the previous four plus the fifth number "1" or "2") example: 5184 on the box (it means 1995); on the bottle you read: 51841 or 51842 example: 8231 on the box (it means 1998); on the bottle you read 82311 or 82312
from 2005 to 2011: 1 number followed by 3 letters both box and bottle example 6ABB (it means year 2006)
example 9HAA (it means year 2009)
example 1AAA (it means year 2011)
since 2012: long codes with multiple letters/numbers
for some reason during year 2008 -and only in 2008- a strange code starting with a letter was used (HAOO, EHAA)
Last edited by Andrč Moreau; 4th April 2013 at 01:31 PM.