Chemistry and Technology of Wine Aging with Oak Chips

Abstract

The use of wood chips is a common winemaking practice that has been permitted in Europe since the early 2000s. The use of oak chips, or other wood alternative products, has not always been favorably viewed by both producers and wine consumers. Beyond possible misuse, however, wood chips are a useful tool for the optimal achievement of numerous oenological objectives, including the extraction of certain volatile odor compounds from oak wood chips as well as compounds that will improve wine quality. This chapter deals with the main oenological uses of oak wood chips, the chemical transformations that underlie this practice and the effect of their utilization on wine quality. A final aspect concerns the main compositional and sensory differences between wines aged in barrel and those aged with alternative products, as well as the discriminative analytical methods used for this purpose.

Aroma Profile of Merlot Red Wine Stored in Stainless-Steel Tanks and Wooden Barrels with Different Toasting Methods

“…The use of wood chips or old barrel fragments with different toasting levels has also been investigated as an alternative to ageing in wooden barrels. It has been shown that wooden chips could be used for short-aged wines and to reuse wood from old barrels, but new wooden barrels result in more complex aromas and higher wine quality [ 32 ], although several other factors must also be taken into account, such as the toasting level, wine type, wood type, barrel age, contact surface between wood and wine and other [ 25 ].…”

Characterisation of Refined Marc Distillates with Alternative Oak Products Using Different Analytical Approaches

“…The use of wood fragments (chips) for the ageing of wines, distillates and vinegars is a widespread practice within the European Union and complies with specific regulations to defend the Protected Geographical Indication (PGI) from possible fraud. Their use, when authorized, is intended to reduce production time and costs [1].…”

“…Moreover, other compounds can be found in oak-aged distillates. Some of them may derive from the Maillard reaction, which occurs during the wood-toasting phase and leads to the formation of coloured compounds (melanoidins) and several aromas with a high olfactory impact, such as pyrazines and furan derivatives [1,6,7].…”

“…Among factors that affect the transfer of xylovolatiles to the distillate the most, the geographic and botanical origin of the wood, the wood grain coarseness, the drying/seasoning methods, the infusion duration, the shape and size of fragments and the surface/volume ratio should be considered [1], but the wood-toasting phase is crucial to the final quality of the distillate. In fact, toasting profoundly changes the structure, chemical composition and physical properties of the wood and is strictly dependent on the applied heat intensity.…”

“…Sliced wood and peeled wood or untoasted poplar chips used once during fermentation to clarify wines and improve their body could be an alternative to conventional chips or barrels for distillate ageing [1,8]. Sliced wood is obtained by cutting the trunk using a very sharp blade of length at least equal to that of the workpiece (trunk or square portion), with a series of cuts that follow one another from its lateral surface along planes parallel to the fixing base.…”