1. Introduction.

Oak has a place in almost every winemaker’s process, but the timing of use, type, size or quantity of oak and extent of use will vary depending on the type of grapes,  style of wine desired,  the scale of wine production, as well as the philosophy of the winemaker.

The use of oak can vary between the following styles that you may be interested in:
 - Fresh, light, ready-drinking wine
 - Refined, aged wine of a particular style
 - Fruit driven, intensely flavoured wine
 - Experimental or unusual styles
 - Unusual (or less common) grape varieties
 - And of course whether the wine is made from grapes or other material, eg country wines.

Oak flavour traditionally was imparted to wine only by use of oak vessels, eg barrels, that at its best transferred pleasant wood aroma and flavour to the wine.  as well as softening some of the harsh flavours, for example from excessive skin or stalk contact. 

Small amounts of oxygen enter the wine through the oak of a barrel soften tannins and add complexity.  Also the water in wine slowly evaporates though the oak, increasing the concentration of alcohol, flavour and aroma compounds.

Direct contact of the wine with “raw” un-toasted wood would introduce aggressive undesirable wood flavours; therefore most oak in contact with wine is toasted to a light, medium or heavy toast.  (A heavier toast with charring also exists which is not generally used with wine, but with specialised spirits).

The heavier the toast, the less aggressive woodiness, but a different spectrum of flavours emerge.