Dry vermouths are usually made from light, dry white wines aged for two to three years, then fortified, sweetened, and infused with the producer's mixture of botanicals. The vermouth is then chilled to crystalize any tartrates, which are then removed during filtration. Caramel is often added to adjust the colour.

European Economic Community, regulation 1601/91 stipulates two styles of dry vermouth, determined sugar levels and alcohol content:
Extra-dry: less than 30 grams of sugar per litre and a minimum of 15% alc./vol.
Dry: less than 50 grams of sugar per litre and a minimum of 16% alc./vol.
No minimum amount of sugar is stipulated, and some dry vermouths contain very little sugar.

Vintage advertisement (Alamy stock image)