Do you need to decant port?

Sediment forms in port that goes into the bottle unfiltered and goes on maturing there.

The Instituto dos Vinhos do Douro e do Porto calls vintage port the only port that matures in the bottle: it is bottled two to three years after the harvest and after about ten years throws a light sediment, which gets thicker the older the wine is. Crusted port is named after that sediment, the crust, and must lie in bottle for at least three years before it may be sold. Traditional LBV that has been bottled unfiltered belongs in the same row.

The difference lies in the maturation and in the treatment at bottling.

Vintage and crusted port mature briefly in large wood and then go to the bottle without fining and without filtration, so that everything that forms later stays behind in the bottle. A filtered LBV is fined and filtered before bottling, and precisely that prevents a crust or sediment from forming. Tawny, colheita and white port mature for years in cask, a colheita at least seven years, and come out of the bottle ready to pour.

Stand the bottle upright for one to two days before you open it, so that the sediment settles at the bottom.

Then open the bottle carefully; with bottles of thirty years and older the cork may crumble. Pour the port into the decanter in one calm movement, with a funnel and if necessary a clean cloth in it to catch the coarse sediment. Hold a strong lamp behind the neck and stop pouring as soon as you see the sediment moving toward the neck. With vintage port, leave a good amount in the bottom.

The older the port, the shorter it should stand in the decanter before serving.

For vintage port of ten to fifty years old, the trade press calculates one to two hours before pouring. A bottle of over fifty years is decanted just before pouring. A vintage port under ten years old may go up to four hours ahead, with plenty of aeration during the decanting, because such a young wine can still be closed.

A decanted port keeps no longer than a port left in its own bottle.

The Instituto dos Vinhos do Douro e do Porto gives an opened bottle of vintage port one to two days, LBV and crusted four to five days, ruby eight to ten days and tawny with an age statement or colheita one to four months. Decanting removes the sediment and adds air, but it does not extend shelf life. According to the trade press, port in a closed decanter goes downhill within about a week.