Article by Charl Theron
Vino Fino Oenological Advice – www.wineland.co.za
Although Cabernet Sauvignon is the best known red cultivar internationally and features in the red wine spectrum of all countries, local pride comes into play when trying to determine which cultivar should wear the “king of red wine” crown. South Africans will likely sing the praises of Pinotage, Italians will differ about whether it should be Nebbiolo or Sangiovese and Argentinians will nominate Malbec. Despite such differences winemakers are bound to agree that it is hard to beat the elegance of Pinot noir. It is therefore small wonder that Burgundy considers other red wines inferior. The Pinot noir wines made by winemakers from New Zealand, Oregon and Sonoma reinforce this opinion.
The phenolic compounds in red wines, namely anthocyanins, tannin monomers and tannin-anthocyanin polymers, form the backbone of the sensorial qualities of red wines. The phenolic compounds also have anti-oxidant qualities, which protect the wine characteristics during red wine vinification and maturation. In view of the fact that concentrations thereof are present in grams per litre amounts, these play a significant role in wine quality.
Anthocyanins are the phenolic compounds that are predominantly reponsible for colour in red wines, but in Pinot noir concentrations thereof are usually lower than in other red cultivars. Pinot noir also contains less of the stable anthocyanin forms and it is therefore essential to extract and stabilise maximum colour during skin contact and alcoholic fermentation. The process of red wine colour stabilisation entails a polymerisation reaction between anthocyanins and tannins. Although Pinot noir grapes have high tannin concentrations, Pinot noir wines are low in tannins. This can most probably be ascribed to the low ratio of skin tannins compared to grapeseed tannins. The anthocyanins, which are responsible for the colour, are easily extracted and are present in high concentrations at an early stage of alcoholic fermentation, but because they are very reactive, sufficient tannins should be present to form stable colour pigments. Because Pinot noir skins have low tannin concentrations, winemakers are obliged to use the grape seeds and stems as supplementary sources of tannins. Since both of these may cause green flavours, astringency and a bitter taste in wines, judicious use thereof is mandatory.
Taking into account the above-mentioned reactions of Pinot noir phenols, the climatic sensitivity of the cultivar and the clonal differences, winemakers cannot depend on terroir alone as a yardstick for quality. Vinification decisions also have to be taken, for example the management of phenolic profiles …