Chase Kesecker, Jean Dodson Peterson, Joshua Toepfer, and Federico Casassa*
*Wine and Viticulture Department – Cal Poly San Luis Obispo, 1 Grand Avenue, San Luis Obispo, CA, 93407 (lcasassa@calpoly.edu)

It is widely accepted that smaller berries provide better extraction of phenolic, chro­matic, and aromatic compounds than large berries. This paradigm is founded upon smaller berries having a much greater solid (skins and seeds) to liquid (pulp) ratio than larger berries. To explore this notion, three different clones of Pinot noir (2A, 115, and 96), were examined over two consecutive growing seasons. At harvest, berries from each clone were manually separated into berry size classes (raisins, 8 mm, 10 mm, 12 mm, and 14 mm), crushed, and made into wine in triplicate fermentations. A 15% saignée was performed on 10 mm berries of clone 115 and the subsequent juice was transferred to another vessel at a rate of 15% must. Across all three clones, 12 mm berries had more seeds/berry, skin and seed dry weights, and a significantly higher solid:liquid ratio than 8 mm berries, the latter in the case of clones 115 and 96. Eight mm berries had higher Brix, higher pH, and less malic acid content than 12 mm berries. Wines made from 8 mm berries had significantly more anthocyanins, tannins, total phenolics, and polymeric pigments than those of 10 and 12 mm berries. For ex­ample, in clone 96 a three-fold and a two-fold increase in wine tannins and polymeric pigments, respectively, was observed in 8 mm wines, relative to 12 mm wines. In clone 115, a 15% saignée and an equivalent must addition to 10 mm berries barely changed the phenolic composition of their respective wines relative to untreated 10 mm wines, suggesting phenolic extraction and retention in clone 115 is not limited, nor negatively affected, within the limits herein set, to the amount of solvent available to solubilize these phenolic classes.

Funding Support: Oregon Wine Board Commission – Agricultural Research Institute