Glucose  – Major sugar used for the alcoholic fermentation in grapes.

Glycerol  – glycerine (glycerol) – A natural constituent of wine (8-20 g / l), derived from the alcoholic

fermentation.  It contributes to the body wine. Its addition (glycérinage) is prohibited and constitutes fraud.

Grafting (Grafting) – Operation of sealing the aerial part of a vine to a different rootstock.

This is a process often done for Vitis Vinifera plants in many countries where the phylloxera is present.

Grape (Grape-variety) – Variety of vine. There are a wide number (> 5000). Made up of berries and stems.

Grape enhancer (Recommanded grape-variety) – Grape planting is recommended and even encouraged so to improve

the quality of wines in certain regions. (ex. Syrah grape as a southern region enhancer).