by Astrid Buica, Aléta Bruwer & Wessel du Toit | 1 Aug, 2019 | Oenology research, Winetech Technical
In this three part series, we explore some fundamental aspects of sulphur and nitrogen foliar fertilisation and the chemical and sensory results of a recent project that took place in South Africa. Foliar fertilisation and wine aroma Vine nutrition plays a...
by Yu Gao, Melané Vivier & John Moore | Oenology research, Winetech Technical
Exploring the secret ingredients in wine enzyme mixes and cocktails. Introduction Wine grapes need to be macerated to extract juice and the key ingredients, such as pigments and tannins, in order to craft wines effectively. This is particularly important in red...
by Heinrich du Plessis, Maret du Toit, Hélène Nieuwoudt, Marieta van der Rijst, Martin Kidd & Neil Jolly | Oenology research, Winetech Technical
This study follows similar studies done by us on Chenin blanc, Chardonnay and Pinotage. The aim of this study was to determine the effect of seven different non-Saccharomyces yeast strains in combination with Saccharomyces cerevisiae and three malolactic fermentation...
by Yu Gao, Melané Vivier & John Moore | 1 Jul, 2019 | Oenology research, Winetech Technical
Improving consistency from the grape to the glass; from the vineyard to the wine. Introduction Vineyards are complex variable systems and perennial crops change from season to season. In any vineyard you have variability from soil and geography; you also have...
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...
