<P> The age of the cognac is calculated as that of the youngest component used in the blend . The blend is usually of different ages and (in the case of the larger and more commercial producers) from different local areas . This blending, or marriage, of different eaux - de-vie is important to obtain a complexity of flavours absent from an eau - de-vie from a single distillery or vineyard . Each cognac house has a master taster (maître de chai), who is responsible for blending the spirits, so that cognac produced by a company will have a consistent house style and quality . In this respect it is similar to the process of blending whisky or non-vintage Champagne to achieve a consistent brand flavor . A very small number of producers, such as Guillon Painturaud and Moyet, do not blend their final product from different ages of eaux - de-vie and therefore produce a "purer" flavour (a practice roughly equivalent to the production of single malt Scotch whisky). Hundreds of vineyards in the Cognac AOC region sell their own cognac . These are likewise blended from the eaux - de-vie of different years, but they are single - vineyard cognacs, varying slightly from year to year and according to the taste of the producer, hence lacking some of the predictability of the better - known commercial products . Depending on their success in marketing, small producers may sell a larger or smaller proportion of their product to individual buyers, wine dealers, bars and restaurants, the remainder being acquired by larger cognac houses for blending . The success of artisanal cognacs has encouraged some larger industrial - scale producers to produce single - vineyard cognacs . </P> <P> According to the Bureau National Interprofessionnel du Cognac (BNIC), the official quality grades of cognac are the following: </P> <Ul> <Li> V.S. (Very Special) or ✯ ✯ ✯ (three stars) designates a blend in which the youngest brandy has been stored for at least two years in cask . </Li> <Li> V.S.O.P. (Very Superior Old Pale) or Reserve designates a blend in which the youngest brandy is stored for at least four years in a cask . </Li> <Li> XO (Extra Old) or Napoléon currently designates a blend in which the youngest brandy is stored for at least six years . The minimum storage age of the youngest brandy used in an XO blend will be increased to ten years in April 2018; this rule was originally scheduled for implementation in 2016 but was postponed due to inadequate stocks . The Napoleon designation, previously unofficial, will then be used to specifically denote those blends with a minimum age of six years that do not meet the revised XO definition . </Li> <Li> Hors d'âge (Beyond Age) is a designation which BNIC states is equal to XO, but in practice the term is used by producers to market a high - quality product beyond the official age scale . </Li> </Ul> <Li> V.S. (Very Special) or ✯ ✯ ✯ (three stars) designates a blend in which the youngest brandy has been stored for at least two years in cask . </Li>

What is the difference between vs vsop and xo cognac
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