Australian wine important resource in the globalisation of wine and wine critic Matt Kramer notes that "the most powerful influence in wine today" comes from Australia. "GSM" is a name commonly used for a red wine consisting of a blend of Grenache, Shiraz (Syrah), and Mourvèdre. Blends where Shiraz is the main component are sometimes referred to instead as SGM. This blend originated from those used in some Southern Rhône wines, including Châteauneuf-du-Pape, though it is also found in South Australia, California (particularly Paso Robles, originating with Tablas Creek Vineyard), and Washington (Columbia Valley); smaller production exists in Argentina and South Africa.
Phenolic content in wine grapes varies depending on the variety with Cabernet Sauvignon, Nebbiolo, Syrah and Tannat being 4 of the most tannic grape varieties. The reaction of tannins and anthocyanins with the phenolic compound catechins creates another class of tannins known as pigmented tannins which influence the color of red wine. Commercial preparations of tannins, known as "enological tannins", made from oak wood, grape seed and skin, plant gall, chestnut, quebracho, gambier and myrobalan fruits, can be added at different stages of the wine production to improve color durability. The tannins derived from oak influence are known as "hydrolysable tannins" being created from