Wine faultA wine fault is a sensory-associated (organoleptic) characteristic of a wine that is unpleasant, and may include elements of taste, smell, or appearance, elements that may arise from a "chemical or a microbial origin", where particular sensory experiences (e.g., an off-odor) might arise from more than one wine fault. Wine faults may result from poor winemaking practices or storage conditions that lead to wine spoilage.
Aging of wineThe aging of wine is potentially able to improve the quality of wine. This distinguishes wine from most other consumable goods. While wine is perishable and capable of deteriorating, complex chemical reactions involving a wine's sugars, acids and phenolic compounds (such as tannins) can alter the aroma, color, mouthfeel and taste of the wine in a way that may be more pleasing to the taster. The ability of a wine to age is influenced by many factors including grape variety, vintage, viticultural practices, wine region and winemaking style.
Fermentation in winemakingThe process of fermentation in winemaking turns grape juice into an alcoholic beverage. During fermentation, yeasts transform sugars present in the juice into ethanol and carbon dioxide (as a by-product). In winemaking, the temperature and speed of fermentation are important considerations as well as the levels of oxygen present in the must at the start of the fermentation. The risk of stuck fermentation and the development of several wine faults can also occur during this stage, which can last anywhere from 5 to 14 days for primary fermentation and potentially another 5 to 10 days for a secondary fermentation.
Acids in wineThe acids in wine are an important component in both winemaking and the finished product of wine. They are present in both grapes and wine, having direct influences on the color, balance and taste of the wine as well as the growth and vitality of yeast during fermentation and protecting the wine from bacteria. The measure of the amount of acidity in wine is known as the “titratable acidity” or “total acidity”, which refers to the test that yields the total of all acids present, while strength of acidity is measured according to pH, with most wines having a pH between 2.
BeaujolaisBeaujolais (ˌboʊʒəˈleɪ , boʒɔlɛ) is a French Appellation d'Origine Contrôlée (AOC) wine generally made of the Gamay grape, which has a thin skin and is low in tannins. Like most AOC wines they are not labeled varietally. Whites from the region, which make up only 1% of its production, are made mostly with Chardonnay grapes though Aligoté is also permitted until 2024 (on condition the vines were planted before 2004). Beaujolais tends to be a very light-bodied red wine, with relatively high amounts of acidity.
RieslingRiesling (ˈriːslɪŋ, ˈriːz-; ˈʁiːslɪŋ) is a white grape variety that originated in the Rhine region. Riesling is an aromatic grape variety displaying flowery, almost perfumed, aromas as well as high acidity. It is used to make dry, semi-sweet, sweet, and sparkling white wines. Riesling wines are usually varietally pure and are seldom oaked. , Riesling was estimated to be the world's 20th most grown variety at (with an increasing trend), but in terms of importance for quality wines, it is usually included in the "top three" white wine varieties together with Chardonnay and Sauvignon blanc.
Ripeness in viticultureIn viticulture, ripeness is the completion of the ripening process of wine grapes on the vine which signals the beginning of harvest. What exactly constitutes ripeness will vary depending on what style of wine is being produced (sparkling, still, fortified, rosé, dessert wine, etc.) and what the winemaker and viticulturist personally believe constitutes ripeness. Once the grapes are harvested, the physical and chemical components of the grape which will influence a wine's quality are essentially set so determining the optimal moment of ripeness for harvest may be considered the most crucial decision in winemaking.
Yeast in winemakingThe role of yeast in winemaking is the most important element that distinguishes wine from fruit juice. In the absence of oxygen, yeast converts the sugars of the fruit into alcohol and carbon dioxide through the process of fermentation. The more sugars in the grapes, the higher the potential alcohol level of the wine if the yeast are allowed to carry out fermentation to dryness. Sometimes winemakers will stop fermentation early in order to leave some residual sugars and sweetness in the wine such as with dessert wines.
White wineWhite wine is a wine that is fermented without skin contact. The colour can be straw-yellow, yellow-green, or yellow-gold. It is produced by the alcoholic fermentation of the non-coloured pulp of grapes, which may have a skin of any colour. White wine has existed for at least 4,000 years. The wide variety of white wines comes from the large number of varieties, methods of winemaking, and ratios of residual sugar. White wine is mainly from "white" grapes, which are green or yellow in colour, such as the Chardonnay, Sauvignon blanc and Riesling.
Pressing (wine)In winemaking, pressing is the process where juice is extracted from the grapes with the aid of a wine-press, by hand, or even by the weight of the grape berries and clusters. Historically, intact grape clusters were trodden by feet but in most wineries today the grapes are sent through a crusher/destemmer, which removes the individual grape berries from the stems and breaks the skins, releasing some juice, prior to being pressed.
