Dat nogal wat wijnboeren met tannine rommelen om fouten te maskeren of wijnen te ‘verzachten’, wisten we al. Daarvoor is het spul in geconcentreerde vorm ruimschoots beschikbaar. Net zoals zuurzakken en houtkrullen. Maar dat tannine ook een negatief effect op de wijnkwaliteit kan hebben, is nu vastgesteld in een onderzoek van een aantal samenwerkende wetenschapsinstellingen: uit Washington, Bologna, Californië en Australië. Onze correspondent vatte de kern samen en verwijst naar de website van de onderzoekers.

“Tannins are an important part of wine quality and are frequently added during winemaking. Some winemakers add tannin to all products as a risk management strategy. Others add tannins to stabilise colour, to modify mouthfeel, to mask green characters or other faults, or to differentiate their wines from similar products, or a combination of these motivations. However, tannin additives and their impact on wine are poorly documented. To characterize a range of oenological tannins and their contribution to wine quality, a tannin product at various concentrations was added to a Merlot wine during barrel ageing. Also, condensed and hydrolysable tannins were added to Cabernet Sauvignon wine post-pressing both at the recommended and at an excessive rate. It was found that adding tannin within the manufacturer guidelines adds significantly less tannin than would be supposed, and in some (maybe many) cases, probably less than is required to have a measurable impact. Adding very high levels of oenological tannins to wine so as to be able to measure an impact on the phenolic parameters had a subsequent negative effect on wine sensory character. The study concluded that many tannin additions may well be unjustified or unnecessary, and have limited or even negative impacts on quality”.