What is the difference between Brut & Demi Sec sparkling wine?

Brut means that the sparkling wine is dry, i.e. not sweet. Sparkling wines are usually made from base wines with high acidity to guarantee that mouth-watering refreshment factor. A final addition of sugar at disgorgement rounds this out without making the wine taste sweet: acid and sugar balance each other. In fact, small amounts sugar act as a flavour enhancer of fruit, rather than as a sweetener. This final addition of sugar is called dosage. Dosage levels are clearly defined by law: