This work has been just pulished in the Australian Journal of Grape and Wine Research in an article entittled Imaging of oxygen transmission in the oak wood of wine barrels using optical sensors and a colour camera
Background and Aims: Wine ageing in oak barrels is characterised by a
series of physical and chemical processes, in many of which oxygen plays
an important role. Therefore, to control better this phase of
winemaking, it is not enough to know that oxygen penetrates into the
barrel through the oak wood; it is also important to know how oxygen
moves through the wood into the barrel, in what quantity and which
factors are involved.
Methods and Results: We attempted to
answer these questions with a high-resolution colour camera, ratiometric
calibration and a planar optode with which the two-dimensional
distribution and dynamics of oxygen within an oak barrel stave were
studied. It was possible to make two-dimensional measurements when
combined with microscopic optics and an appropriate camera, which
permitted the measure of the transmission of oxygen into the barrel
through the oak stave and the study of the mechanism of transmission.
The trial was applied to both dry and wet oak wood, which revealed how
the moisture content of the wood influenced oxygen transmission. The
measurements were made in an airtight chamber under controlled
temperature and pressure, which accurately reproduced the conditions of a
stave in an oak wood barrel filled with liquid.
Conclusion: We
were able to visualise the diffusion of oxygen in both dry and in wet
French oak wood under conditions similar to those operating in a barrel.
The moisture content of the wood influenced the oxygen transmission
rate (OTR) through the wood.
