In principal, vermouth is an aromatized fortified wine that has been flavoured with various botanicals. There are a couple of AOC’s for this, notably Vermouth de Chambéry has to be produced within France’s Savoy region (surrounding Chambéry), and the other being vermouth di Torino (produced in the area surrounding Turin).
Aromatized drinks fall into 3 categories
i) aromatized wine or wine-based aperitif
ii) aromatized wine based drink
iii) aromatized wine-produced cocktail
Vermouth falls in to the first category, but it is not the only thing that falls in to it, there are further categories within it.
The rules for i) are that it must contain a minimum of 75% wine, with only the further addition of fresh or fermented grape must or alcohol added to it. It may also be flavoured with natural flavouring substances, aromatic herbs, spices and flavouring foodstuffs. Sweetening and caramel can also be added.
The level of sugar in the final liquid determines what can be put in the label
i) Extra Dry – less than 80g sugar per litre
ii) Dry – less than 50g sugar per litre
iii) Semi-dry – between 50g & 90g sugar per litre
iv) Semi-sweet – between 90 & 130g sugar per litre
v) Sweet – over 130g sugar per litre
It must also contain between 14.5% to 22% abv in its final state, though dry must be a min 16% and extra dry a min of 15%.
There are a few different categories of aromatized wine, and here are the legal distinctions between them:
Must contain one of three types of wormwood (Artemisia absinthium, Artemisia pontica or Artemisia maritime). It can only be sweetened with caramelised sugar, sucrose, grape must, rectified grape must and concentrated grape must.
Must contain quinine
Must contain gentian
Wormwood and gentian must be apparent in the final character