micro-oxygenation in contemporary winemaking - Cape Wine ...

Micro-oxygenation in Contemporary WinemakingThese then are the essential benefits of micro-oxygenation as claimed by the industry:treating your red wine with a course of micro-oxygenation will result in a softer, moreaccessible wine with improved colour and better flavour (Parish et al., 2000; Paul, 2002).The advantage of micro-oxygenation emphasised most prominently by supporters is theimprovement in wine structure. Indeed that was why the technique was originallydeveloped – to make harsh tannic wines more accessible and ready to drink earlier. In factthe Vinovation promotional material prefers the term ‘integrated tannin management’ tomicro-oxygenation (Vinovation, 2001b). It is proposed that treatment with low doses ofoxygen will speed up tannin polymerisation resulting in softer tannins, decreasedastringency, and an overall improvement in mouthfeel.The added oxygen will also promote reactions between anthocyanins and tannins toproduce larger molecules known as polymeric pigments. Polymeric pigments are moredeeply coloured and are more resistant to degradation, effects of pH changes, andbleaching by sulphur dioxide (SO 2 ). So that the overall impact of micro-oxygenation shouldbe both enhanced red wine colour and more stable colour over time (Paul, 2002).These two benefits, improved palatability and enhanced colour, are more traditionallyachieved by ageing red wine in oak barrels over a period of months. Although maturation inoak barrels will also impart advantageous oak flavours to wine, it was established in the1970s and 80s that many of the benefits of barrel-ageing are due to the slow diffusion ofoxygen through barrel walls and that the resulting low doses of oxygen promote beneficialoxidation reactions which modify wine structure and colour (Atanasova et al., 2002;Cheynier, 2002). Indeed, it was those discoveries that suggested to the inventors of microoxygenationthat low dose oxygen treatment would be an alternative way to achieve thesame outcomes. Therefore, micro-oxygenation is frequently presented as a substitute forbarrel maturation, with the possible advantages of lower cost, faster maturation, and morescientific control (Jones et al., 2004; Paul and Gore, 2006; Dykes and Kilmartin, 2007).With the addition of oak substitutes, such as oak staves or oak chips, it may then bepossible to replicate completely the effects of oak barrel-ageing in stainless steel tanks,which is an attractive option for winemakers, particularly for medium-range wines(Zoecklein et al., 2002; Goode, 2005).Interestingly, although these changes induced by micro-oxygenation are interpreted bymany as speeding up the ageing of wine (Zoecklein et al., 2003), Vinovation takesconsiderable effort in their documentation to present it differently. As shown in Table 1,11