Bentonite alternatives
Bentonite is most probably one of the additives used most generally during winemaking. It can be used together with other fining agents for the clarification of juice or wine, but is mainly used for the protein stabilisation of white wine. Its use has however certain...
Winetech vine and wine innovation watch: Fighting vineyard pathogens with UV light
Powdery mildews have been around for millions of years. As time progressed, they evolved and are acutely able to sense and utilise light to develop optimally. Knowing this, scientists can cleverly use their superpowers against them. Is this completely new...
Grape flavan-3-ol composition under altered light and temperature conditions in Cabernet Sauvignon (Part 2)
This study aimed to investigate flavan-3-ol composition under altered microclimatic conditions in Cabernet Sauvignon grown in the Stellenbosch Wine of Origin District. Introduction Proanthocyanidins or condensed tannins are mostly situated in the solid parts of...
Metschnikowia pulcherrima yeast and its role in winemaking
M. pulcherrima is least influenced by must nitrogen composition compared to S. cerevisiae and other non-Saccharomyces yeasts frequently encountered in wine fermentation. Current and previous names Metschnikowia pulcherrima has previously been designated under...
Eutypa-like fungi associated with grapevine cankers and dieback
The aim of this study was to determine the occurrence of Eutypa-like species associated with dieback and canker-affected grapevines and to determine their status as grapevine pathogens. Introduction The trunk disease complex which comprises of grapevine canker...
Grape flavan-3-ol evolution under altered light and temperature conditions in Cabernet Sauvignon (Part 1)
This study aimed to investigate flavan-3-ol biosynthesis under altered microclimatic conditions in Cabernet Sauvignon grown in the Stellenbosch Wine of Origin District. This was part of a larger study in which flavonoid evolution and composition by manipulating the...
The integration of multiple view points for adaptation/mitigation strategies in the context of warmer and drier future (Part 5)
The final part of the series deals with the transition of fundamental research into the domain of the decision maker, through web applications to aid long and short term decision making in the context of climate change. Highlights from previous papers in the...
Thiols in red wine (Part 4): The matrix
It is all about the (wine) matrix. The work presented in this article forms part of a series of experiments on the interaction between thiols and red wine matrices as described in Part 1. Background The key word for this latest aspect of thiols in red wine...
Torulaspora delbrueckii and its role in winemaking
Torulaspora delbrueckii is generally regarded as a low producer of aroma compounds, in particular higher alcohols and esters, however, this is strain dependent. Current and previous names Torulaspora delbrueckii has had many synonyms, amongst them Saccharomyces...
The sanitation of Brett-infected barrels
Brett has become a fashion word in the wine industry. Although it causes typical off-flavours, other wine faults that are not caused by it are also sometimes attributed to it. It applies especially when some wine writers are looking for descriptive terms to evaluate a...
Winetech vine and wine innovation watch: Magnetic nanoparticles for the protein stabilisation of wines
Who did what? Australian researchers found that acrylic-acid-based plasma polymer coated magnetic nanoparticles can effectively protein stabilise white wines. Why was this investigated? Currently mostly white wines are treated with bentonite before bottling....
Yeast and its ability to release thiols
Yeast strains vary significantly in their ability to produce varietal thiols. Introduction The varietal thiols, mainly 3-mercaptohexan-1-ol (3MH), 3-mercaptohexyl acetate (3MHA) and 4-mercapto-4-methyl-pentan-2-one (4MMP) are the three major varietal thiols...
The phenolic compounds of white wines
Phenolic compounds occur widely in nature. As result of the colour and astringency of red wines everybody is aware of the role of phenols. It can however also play an important role in the colour and quality of white wines. Phenolic compounds are characterised by a...
Incidence and spread of aster yellows
Symptoms associated with aster yellows (AY) vary during the season and between cultivars. AY is caused by a phytoplasma, Candidatus Phytoplasma asteris. Phytoplasmas are very primitive bacteria without cell walls, which occur in the vascular tissue of the plant. The...
Lachancea thermotolerans yeast and its role in winemaking
L. thermotolerans contributes to the production of wines with enhanced mouthfeel, floral notes, fruitiness and freshness. Current and previous names Lachancea thermotolerans is the type species of the genus Lachancea, which was proposed and validated in 2003...
Indigenous leafhopper transmits aster yellows
Thus far, the indigenous leafhopper Mgenia fuscovaria is the only confirmed vector of the phytoplasma that causes aster yellows in South Africa. Aster yellows is a phytoplasma disease which causes serious yield loss. Severely infected grapevines may have to be...
Thiols in red wine (Part 3): Thiols interaction in a Pinotage base wine
When does 1 + 1 = 3? The work presented in this article forms part of series of experiments on the interaction between thiols and red wine matrices as described in Part 1. Background In sensory science there are terms that describe the relationship between...
Botha Cellar – exposure and continuous transfer of knowledge make a difference
Botha Cellar is situated near the Waaihoek Mountains on the Ceres road, approximately twenty minutes from Worcester. This cellar processes annually large volumes of wine with the assistance of twelve permanently employed cellar assistants. During the annual harvest,...
