It is well known that free varietal thiols, in particular 3-mercaptohexanol (3MH) and 3-mercaptohexyl ace-tate (3MHA), are important constituents to the aroma of New Zealand Sauvignon blanc wines.
Over the past two years, the AWRI has received 69 wine samples suspected of being affected by mousy off-flavour. The character has been mostly observed in white wines.
After fermentations, the crude wine is a turbid medium not accepted by the consumer therefore, it needs to be filtered
Residual grape solids (suspended particles) in white and rosé musts vary depending on the clarification pro-cess. These suspended solids contain lipids (more especially phytosterols) that are essential for yeast meta-bolism and viability during fermentation in anaerobic conditions.
In oenology, bio-protection consists in adding bacteria, yeasts or a mixture of microorganisms on grape must before fermentation in order to reduce the use of chemical compounds such as sulphites.
Copper (Cu) is known to substantially impact wine stability through oxidative, reductive or colloidal phenomena. Recent work has shown that Cu exists predominantly in a sulfide-bound form, which may act as a potential source of sulfidic off-odours in wine and hence contribute to reductive flavours
In winemaking, the appearance of turbidity in white and wine is a serious visual defect, which lowers significantly its commercial value. A major cause of the formation of turbidity in wine is attributed to the presence of temperature-sensitive proteins.
Copper (Cu) is known to substantially impact wine stability through oxidative, reductive or colloidal phenomena. Recent work has shown that Cu exists predominantly in a sulfide-bound form, which may act as a potential source of sulfidic off-odours in wine and hence contribute to reductive flavours
PR proteins can cause haze in wines, and the risk is to keep the wine unsold. Generally, in winemaking bentonite solves this problem by removing proteins, but it is not a renewable resource, has poor settling, which means difficulty in filtering after use and a considerable loss of wine, it is not a specific adsorbent and may reduce aromas and flavor compounds
Œnococcus oeni is a wine-associated lactic acid bacterium performs the malolactic fermentation, which improves the taste and aromatic complexity of many wine.
During wine alcoholic fermentation, yeasts produce volatile aroma compounds from sugar and nitrogen metabolism. Some of the metabolic pathways leading to these compounds have been known for more than a century.
Nowadays the use of Torulaspora delbrueckii is more and more common in winemaking. However, its behavior in presence of Saccharomyces cerevisiae is not always predictable.
Nowadays the use of non-Saccharomyces as starters of alcoholic fermentation (AF) has increased because of the modulation of the organoleptic profile of wines
SO2 is used during winemaking for its anti-oxidative and anti-microbial properties. A high SO2 concentration in the wine has negative impacts by hiding wine aromas and delaying malolactic fermentation.
Through the years, extensive studies have been conducted on fungal biodiversity during the winemaking process: from the vineyard until aging.
The wine aroma is constituted by hundred of volatile chemical compounds that depend on many viticultural and oenological factors.
Primary and secondary metabolites are major components of grape composition and their balances define wine typicality
Climate is considered one of the main factors that determines the aptitude of a specific location for growing grapes and producing high quality wine, being in that sense one of the main elements defining the concept of terroir