This article aims to provide the reader with one of the key elements of wine: tannin. It is the first in a series of articles that will each cover one specific term or element involved in the process of wine making and tasting. At the end of the series you should be able to hold your own at any tasting event.
What is it?
Tannin refers to certain chemical compounds that can affect the colour, aging ability and texture of wines. It is not something you can taste or smell, but you may be able to notice its presence when you taste. The reason for this is that it interacts with protein, such as the proteins naturally found in saliva. It is difficult to describe how it feels in the mouth, the best way to describe it is the ‘dry’ sensation you get when you drink steeped tea. In red varieties the dryness is usually accompanied by a level of acidity on the pallet.
Tannins are derived from the grape skins, seeds and stems during the a process called 'maceration'. This process also releases flavour and colouring compounds. You may have heard of the term maceration before in cookery books, a common example is the maceration of strawberries in balsamic vinegar. The term means to soften by soaking.
Tannins in white varieties
Unlike red varieties, white wines are usually very low in tannins. Under certain circumstances white wines do contain tannins this happens when the grape juice comes into contact with the skins for a brief period of time before fermentation or if the finished product is aged in oak. The aging process releases a secondary source of tannin from the barrels.
Tannins in red varieties & food pairing
As stated earlier red varieties tend to have high levels of tannin, this is where red wine gets its colour as the skinless grape tends to have a greyish translucent hue. Like white wines, the tannin levels in red wine can also be increased by aging the wine in oak barrels. Red wine is often aged to add flavour and body to the finished product. Tannins also contribute to the way we experience food as it interacts with proteins and fats. The dissolving effect of saliva is inhibited by the tannins and a new dimension is added to both the food and the wine.