by Rodney Hart, Bongani Ndimba & Neil Jolly | 1 Jun, 2019 | Oenology research, Winetech Technical
During alcoholic fermentation of grape must, the metabolic activity of Saccharomyces cerevisiae leads to a range of compounds, some of which enhance tropical fruit aroma, e.g. volatile thiols. Introduction Two thiols in particular, namely 3-mercaptohexanol...
by Astrid Buica, Gabriella Petrovic & Jose-Luis Aleixandre-Tudo | 1 May, 2019 | Oenology research, Winetech Technical
Due to the complexity of the grape juice matrix and the increasing consumer demand for quality wines, monitoring the grape juice composition becomes essential. Yeast assimilable nitrogen (YAN), a critical component of the grape juice matrix, is, however, often...
by Astrid Buica, Gabriella Petrovic & Jose-Luis Aleixandre-Tudo | 1 Apr, 2019 | Oenology research, Winetech Technical
This study aimed to investigate how well cultivars could be predicted based on their amino acid profile, regardless of origin or vintage. The amino acid results obtained from the survey of 738 grape must samples (2016 and 2017 harvests) were presented in Part 1, while...
by Karien O'Kennedy | Oenology research, Winetech Technical
This study demonstrated the different effects of the same amount of smoke on different grape varieties. Introduction It is well-documented that wines made from grapes that were exposed to smoke from bushfires can contain smoky and ashy characteristics.1 These...
by OIV | 1 Mar, 2019 | Oenology research, Viticulture research, Winetech Technical
The 16th General Assembly of the International Organisation of Vine and Wine (OIV), which met on 23 November 2018 in Punta del Este (Uruguay), adopted a total of 20 resolutions. Decisions on viticulture and the environment • In the field of viticulture, the OIV...
by Astrid Buica, Gabriella Petrovic & Jose-Luis Aleixandre-Tudo | Oenology research, Winetech Technical
The work presented aimed to elucidate the amino acid profile of a number of grapevine cultivars relevant to the South African wine industry using 738 grape must samples obtained during the 2016 and 2017 harvests. Part 1 presents the findings of the survey, while Part...
by Karien O'Kennedy | Oenology research, Winetech Technical
In the past 10 years various studies were published that highlighted these three entities and their roles in winemaking. It is therefore worthwhile to take a closer look at what they are, what they do and why winemakers should be excited. What they are Chitin is the...
by Valeria Panzeri, Jeanne Brand & Astrid Buica | 1 Feb, 2019 | Oenology research, Winetech Technical
When evaluating wines, we have two main tools at our disposal: sensory and chemistry. The chemical profile of a wine is made up of a multitude of compounds, but we cannot reduce a wine to a list of substances, no matter how comprehensive. In contrast, sensory...
by Astrid Buica, Gabriella Petrovic & Jose-Luis Aleixandre-Tudo | Oenology research, Winetech Technical
A Big Data approach can be used in winemaking, using our YAN work as illustration. Unlike other fermented beverages, wine’s appeal does not stem from its consistent flavour and aroma, but instead from the unique sensory experience that it can offer, from one vintage...
by Karien O'Kennedy | Oenology research, Winetech Technical
Australian researchers did an in depth study of the compositions of 14 commercial grape-derived tannins and eight mannoproteins obtained from five different suppliers in the Australian market.1 They found significant differences in the compositions of these commercial...
by Caren Jarmain | 1 Jan, 2019 | Oenology research, Viticulture research, Winetech Technical
During the past season, with many people living in the Western Cape trying to survive with a mere 40 to 50 L of water per person per day, many figures were quoted reminding us just how much water is commonly used in our daily living. For example, that about 19 L of...
by Karien O'Kennedy | Oenology research, Winetech Technical
In a recently published study(1) researchers evaluated the effect of diammonium phosphate (DAP) and a commercially available organic yeast nutrient on Chardonnay aroma. The main finding of the study was that the addition of yeast nutrients, compared to no additions in...
