Winemaking
Grenache is often used as a blending component, adding body and sweet fruitiness to a wine. The grape can be troublesome for the winemaker due to tendency to oxidize easily and lose color. To compensate for the grape's naturally low tannins and phenolic compounds, some producers will use excessively harsh pressing and hot fermentation with stems to extract the maximal amount of color and phenols from the skins. This can backfire to produce green, herbaceous flavors and coarse, astringent wine lacking the grape's characteristic vibrant fruitiness. To maintain those character traits, Grenache responds best to a long, slow fermentation at cooler temperatures followed by a maceration period. To curb against oxidation, the wine should be racked as little as possible. The use of new oak barrels can help with retaining color and preventing oxidation but too much oak influence can cover up the fruitiness of Grenache.
The high levels of sugars and lack of harsh tannins, makes Grenache well adapted to the production of fortified wines, such as the vin doux naturels (VDN) of the Roussillon region and the "port-style" wines of Australia. In these wines, the must ferments for 3 days before grape spirit is added to the must to halt the fermentation and the conversion of sugar into alcohol. The high alcoholic proof grape spirit brings the finish wine up to 15-16% alcohol. These wines can be made in a rancio style by leaving it outside in glass demi-johns (or carboys) or wooden barrels where the wine bakes in the sun for several years until it develops a maderized character and flavors of sour raisins, nuts and cheese. These fortified VDNs and port-style wines have longevity and can be drinkable well into their third decade. .
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