The main difference between a barrel made from new oak and a barrel made from recycled oak is the number of times the barrel has been used. New oak barrels are made from freshly cut oak and have not been used to age any wine or spirit before. Recycled oak barrels, on the other hand, have been used at least once to age a wine or spirit and have been reconditioned for reuse. The recycled oak barrels impart not only the flavour and characteristics of the oak but also the flavour of the previously stored wine or spirit.
New oak barrels are generally considered to be more expensive than recycled oak barrels, as they require more labor and resources to produce. The wood is also more likely to be more dense and tight-grained in new oak barrels, which can affect the rate of aging and the flavour profile imparted to the wine or spirit. New oak barrels will impart more robust and pronounced flavours to the wine or spirit it is aging than a recycled oak barrel would.
Recycled oak barrels have already imparted some of their flavour and characteristics to the wine or spirit that was previously aged in them, and thus will tend to impart a more subtle and nuanced flavour profile to the wine or spirit it is aging now. These barrels can also impart some of the flavour of the previously stored wine or spirit. Recycled oak barrels can also have a more porous structure, which can result in faster aging.
The choice of using a new or recycled oak barrel depends on the desired flavour profile, and the price point of the distillers. Premium wines or spirits may be aged in new oak barrels to impart more pronounced and robust flavours, while other wines or spirits may use recycled barrels to impart more nuanced and subtle flavours and to gain some of the previously stored wine or spirit flavour.