One of the questions I am often asked most often is “why is there a blob of white paint” on my bottle of Vintage Port; indeed, some customers refuse to buy a bottle with white paint on it.

So what is this paint there and what is it for?
The white paint on a Port bottle is often known as a “splash mark”. It is a dash of white paint, whitewash or chalk that is applied in the Port cellars in Vila Nova de Gaia in Oport.. Sometimes it is a neat blob of white paint on a vintage Port bottle, other times it is a real splash – and it seems to vary from Port house to Port House and, no doubt, depends who was working in the cellar on particular day and how much of a hurry they are in!
The reason for the splash mark is so that one can tell which way “up” the bottle has been whilst it has is quietly, laying down in the in the cellar. The white daub or “splash mark” tells the cellar master which way up the bottle has been cellared. Therefore, if the bottle is left one one side the sediment will all collect on that side.
Why is this useful?
For ths consumer it is useful information for when it it is time to decant that special bottle of Port. Vintage Port did not legally have to be labelled for sale until it became law with the 1977 Port vintage, so there was often no label to see which way up the bottle was (the vintage and name of the Port would be on the capsule and the cork). If the bottle is handled carefully with the white paint mark uppermost, there is less chance of the sediment being disturbed. I say “was useful information ” because I think that the splash mark on a bottle of vintage Port is a bit of a throw back to the old days, perhaps when a bottle of Port would be taken straight from a cellar, decanted and served straight a way (perhaps using a Port cradle).

Today, for most people who drink vintage Port, it is somewhat of an occasion which allows the person serving the Port to leave the bottle upright for four or five days (as I recommend) before they serve it which allows all the sediment to settle to the bottom of the bottle and means the Port can be much more successfully decanted. When a consumer has a bottle of Port now, it will invariably have a label on the bottle, so there is no reason for the splash mark anymore, however some Ports still come with the white mark on it. Some producers, like Niepoort, stone fire their bottles.
Read more about Decanting Port.