Article

Phenolics and Tannins

An understanding of what is happening in wine on a chemical basis can be very useful in influencing choices regarding processing options and timing of activities for different wine styles. Unfortunately winemaking chemical nomenclature, chemical analyses, and interpretation of results can be daunting for those without a background in chemistry. Perhaps one of the most complicated subjects in wine chemistry is phenolics, the chemistry of phenolic aroma molecules, anthocyanins, and tannin. I received an undergraduate degree in chemical engineering, yet even for me it has taken many years and much study to wrap my head around how phenolic chemistry impacts processing options for different wine styles. I’m still learning, and there are research questions yet to be answered, but in a series of articles I will try to discuss the topic in ways that give home winemakers useful information in determining the best processing options for the wine styles they produce.  Let’s begin with a basic rundown of the chemistry of phenolic and polyphenolic molecules. Starting with the most basic structure, a phenol is defined as a six-carbon ring with