Where does tannin come from? That was a debate my wife was asked to adjudicate on recently; one person said that it came from the grape skins, another was equally sure it came from wooden barrels. As you might expect, Hilary knew the answer and, fortunately in this case, was able to tell both protagonists that they were correct.
Let me first define what we mean by tannin: you can’t actually taste it but it’s that drying or astringent sensation you feel on your gums and the sides of your mouth when you drink many red wines, especially young reds made with grapes such as Cabernet Sauvignon or Shiraz. Much more rarely, you might also find some tannin on a rosé and even on the odd white – I’m thinking mainly of the current fashion for ‘orange’ wines – white wines made in the same way as a red. And you get the same feeling if you drink tea that has been left brewing too long.
The reason you find tannin in red wines more than in whites is down to the different way the wines are made; reds are fermented with the juice in contact with the skins in order to extract colour and, as a by-product, the process extracts tannins from the grape-skins too. For most white wines, on the other hand, the juice is normally separated from the skins before the fermentation takes place and so tannin from that source is left behind.
But, as one of the people in the discussion said, tannin can also come from wooden barrels. Not all wines are made or stored in wood but, if they are, and especially if the wood is new, then you might find a similar, drying tannin sensation (although many people simply regard it as part of the oaky taste). How to distinguish between grape-skin tannins and wood tannins in a red wine is one for the experts and, unless you’re particularly sensitive to them, isn’t something that most people need worry about.
But, if you open a wine and find it is too tannic for your taste, simply decant it and leave it in contact with air for as long as you can before drinking it. And, let it accompany protein-rich food. These 2 ‘tricks’ will help and make the tannins appear ‘softer’ and the wine will seem more harmonious and attractive.
The reasons behind the differences in taste between one type of wine and another are covered in more detail in a piece I’ve written for the Stoke Lodge website. Go to http://www.bristolcourses.com and type in ‘Wine’ in the key words box and follow the link.