Cork, defined

The term foam is defined as a gaseous void surrounded by a much denser continuous matrix, generally a liquid or a solid phase. As a result of the distinct characteristics of the two phases, such cellular materials are able to feature unique properties. Since nature successfully demonstrated their use in manifold examples, such as bones, wood, plant stalks, cork, and sponges, foams have also sparked interest for technical application. Nowadays, a broad range of cellular materials based on metals, ceramics as well as polymers, is readily available, and their structures are as versatile as their applications. 

When microscopically examined, this group of precipitates lack defined shape and generally assumes color reflective of the wine. Precipitates in this category include protein, phenolics (and complexes of the two), copper, and iron instabilities (casses) as well as paraffin used to coat corks. 

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