The Hydrodynamics of Wine Swirling

Winetech scan newsletter

issue #49                          JANUARY 2012

Originally posted by Winetech – Newsletter Issue #49 – January 2012

In wine tasting, swirling of the glass is necessary to release the bouquet and is usually obtained by a gentle circular (orbital) movement. The wave generated by this movement propagates along the glass wall and enhances oxygenation and mixing. Recently, similar orbital shaking has been applied to large scale bioreactors for the cultivation of cells expressing recombinant proteins (e.g. antibodies), and thus the physics of the process is of significant interest.

                      

A study observed a large variety of wave shapes in the swirled glass (see above), the most simple being a wave with one crest and one trough. More complex shapes, featuring multiple crests and troughs were also observed. Under certain conditions the wave could ‘dry’ a portion of the vessel bottom, or break. Subsequent mathematical analysis found that there are three dimensionless parameters governing the shape of the free surface. Each combination of the free parameter has a peculiar balance of forces, generating a particular wave shape. A video of the various waves obtained may be downloaded at http://arxiv.org/abs/1110.3369