Search results
Results from the WOW.Com Content Network
The natural occurrence of fermentation means it was probably first observed long ago by humans. [3] The earliest uses of the word "fermentation" in relation to winemaking was in reference to the apparent "boiling" within the must that came from the anaerobic reaction of the yeast to the sugars in the grape juice and the release of carbon dioxide.
The primary role of yeast is to convert the sugars present (namely glucose) in the grape must into alcohol.The yeast accomplishes this by utilizing glucose through a series of metabolic pathways that, in the presence of oxygen, produces not only large amounts of energy for the cell but also many different intermediates that the cell needs to function.
Yeast need a reliable source of nitrogen in forms that they can assimilate in order to successfully complete fermentation. Yeast assimilable nitrogen or YAN is the combination of free amino nitrogen (FAN), ammonia (NH 3) and ammonium (NH 4 +) that is available for a yeast, e.g. the wine yeast Saccharomyces cerevisiae, to use during fermentation.
For premium support please call: 800-290-4726
For premium support please call: 800-290-4726 more ways to reach us
Wine is usually made from one or more varieties of the European species Vitis vinifera, such as Pinot noir, Chardonnay, Cabernet Sauvignon, Gamay and Merlot. When one of these varieties is used as the predominant grape (usually defined by law as minimums of 75% to 85%), the result is a "varietal" as opposed to a "blended" wine. Blended wines ...
To start primary fermentation, yeast may be added to the must for red wine, or may occur naturally as ambient yeast on the grapes (or in the air). For white wine, yeast may be added to the juice. During this fermentation, which often takes between one and two weeks, the yeast converts most of the sugars in the grape juice into ethanol (alcohol ...
Vermouth is a fortified wine flavoured with aromatic herbs and spices ("aromatised" in the trade) using closely guarded recipes (trade secrets). Some of the herbs and spices used may include cardamom, cinnamon, marjoram, and chamomile. [15] Some vermouth is sweetened. Unsweetened or dry vermouth tends to be bitter.