Reasons for decanting

The most obvious reason for decanting a wine is to separate it from any sediment that has formed in the bottle which not only looks unappetizing in the glass, but usually tastes bitter and/or astringent. Before winemakers mastered the art of clarification, this was necessary for all wines. Today such a justification of the decanting process effectively limits it to those wines outlined in ageing as capable of development in bottle, in most of which some solids are precipitated as part of the maturation process. Vintage and crusted ports in particular always throw a heavy deposit (since they are bottled so early in their evolution), as do red wines made with no or minimal filtration. It is rare for inexpensive, everyday table wines to throw a deposit, and most large retailers insist on such heavy filtration that a deposit is unlikely (although not unknown in older, higher-quality reds). To check whether a wine bottle contains any sediment, stand it upright for an hour or more and then carefully hold it up to the light for inspection at the base (although some bottles are too dark for this exercise to be effective).