Up, to recent times, only fine white table-cloth restaurants employing pompous sommeliers (wine servers in English) decanted some expensive red wines, and occasionally vintage port, if an when a full bottle was sold. Decanting is an age-old practice in wine circles and restaurants, and involves nothing more than pulling the cork and carefully transferring the content of the bottle to another. In olden times, old red Bordeaux (a k a claret) and vintage ports were decanted with great fanfare and theatrical behaviour in classical restarts since both throw a sediment as they age in the bottle and render the wine in the glass murky. Most wines benefit from decanting; some more than others. For white wines, decanting should help dissipate free sulphur often used in wineries as and antioxidant. In addition, some people are allergic to sulphites, which should not be confused with sulphides that cause the wines to smell like rotten eggs, and/or onion skin.
Sulphides that occur naturally during wine making because as fermentation nears completion, the redox potential (oxidation and reduction) can fall so low that residual fungicides and even sulphur dioxide, can be reduced to hydrogen sulphide. This fault can be easily detected by the winemaker as it smells like rotten eggs and can be eliminated easily by aeration. Decanting benefits the flavour of the wine due to evaporation, thus concentrating fruitiness and allowing sulphur dioxide to disappear. Oxygen-deprived wines benefit, but not very old wines from decanting. Red Bordeaux and Syrah based wines become more focused. During decanting, aeration magnifies oak components i.e. vanilla and cedar, pending on the provenance of the wood. American white oak contains more vanilla than European oak. The amount of aeration must be carefully judged. This can be done by the design of the decanted. Some have wide bases, others narrow. The former are best for relatively young red wines and for quick aeration. Breathing a bottle of wine requires a long time as the surface exposed to air is very small (about 3 cm in diameter) In a wide bowl glass, the wine will breathe much faster if there us no decanted to fall back on. In any restaurant, wine, particularly red wine should be decanted, pending vintage, grape variety and quality, but the process is important. Actually decanting ought to be part and parcel of good service.
Article contributed by Hrayr Berberoglu, a Professor Emeritus of Hospitality and Tourism Management specializing in Food and Beverage. Books by H. Berberoglu
