The ageing of high quality brandies requires a period of storage in wooden barrels. Several studies have showed the great influence of the seasoning process on the characteristics of oak wood and their influence on wines and brandies quality. This study provides, for the first time, specific information about the seasoning effects on portuguese chestnut wood from two different geographical origins, namely on the moisture content and chemical composition over eighteen months of open-air seasoning. Concerning the drying process, the chestnut wood can be used for the barrel making after six months of seasoning, but the remained period will be necessary for the maturation process. The seasoning time, the geographical origin and the stack layer have a significant effect on the moisture content, colour intensity, dry extract and content of some low molecular weight compounds of the chestnut wood studied.