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Wine Expert #7 – H2S PRODUCTION BY WINE YEAST DURING ALCOHOLIC FERMENTATIONHydrogen sulphide (rotten egg) aroma is a serious fault in wine and will result in quality loss in the final product. Its production is mainly found during alcoholic fermentation. H2S production by wine yeast varies based on the yeast used as well as on the environmental factors, especially the assimilable nitrogen concentration and micronutriens present. […]
Aug 10, 2015
Winemaking Update #1-2015 A new concept of selected Lactobacillus plantarum for high pH winesThe tendency to harvest higher maturity grapes, resulting in higher pH and alcohol wines, seems more favorable to the development of indigenous bacteria. To limit the development of unknown indigenous flora, which can lead to the production of undesirable sensory deviations, co-inoculation is an interesting winemaking option and using selected Lb. plantarum in the freeze-dried […]
Aug 10, 2015
Glycerol and winemakingGlycerol is a non-volatile compound which has no aromatic properties, but which significantly contributes to wine quality by providing sweetness and fullness. This Issue of ‘The Wine Expert’ explores its properties and the ways to influence its production. Wine Expert – 120321 – WE Glycerol and WInemaking
Dec 9, 2014
SO2 production by wine yeast during alcoholic fermentationThis issue of ‘The Wine Expert’ will discuss how sulphur dioxide is not only an exogenous compound, but is also produced by yeast during alcoholic fermentation. An understanding of this is important to ensure successful MLF. Wine Expert- 1407 – SO2 Production by Wine Yeast During Alcoholic Fermentation
Dec 9, 2014
The Fermentation of Fructose in WinemakingGlucose and fructose are the main fermentable sugars in wine must. During alcoholic fermentation, yeast convert most of the glucose and fructose present into alcohol and CO2. Saccharomyces cerevisiae is a glucophilic yeast, preferring glucose over fructose. This issue of ‘The WIne Expert’ further explains this phenomenon.Wine Expert- The Fermentation of Fructose in winemaking 2013
Dec 9, 2014
MLF Bacteria – Efficient Contributors to WinestyleThe effects of malolactic fermentation (MLF) on wine aroma and chemical properties of Australian Cabernet Sauvignon were explored at the AWRI , by inoculation with different selected Oenococcus oeni. Significant compositional differences occurred in response to the different MLF treatments and strain dependent changes in volatile aroma compounds were observed. Increases in fruity esters were associated […]
Nov 6, 2014