Poly want a . . . phenol?

When I received an email invitation to participate in a technical tasting panel on polyphenolics at the Oregon Wine Industry Symposium, I was nervous. Poly what??

OK, so I'm no chemist, but I did have an understanding of the basics behind phenolics (or polyphenolics--multiple phenolics), a group of chemical compounds that occur naturally in grape skins, seeds, and stems. But on the panel would be true scientists who study, test, and measure the intricacies of phenolics, as well as true winemakers who constantly deal with managing phenolics in their wines. Their knowledge of the subject is chasms deeper than mine . . . as was the audience who would consist of pretty much all the leading winemakers in Oregon. What value could I lend to such a panel?

Well, it turns out that I did have something to contribute: the consumer perspective.

But first a bit about polyphenols. To simplify, phenolics in red wines are commonly associated with color depth and mouthfeel. The deeper the color, the more phenolics in the wine, and the more astringent the mouthfeel, the more phenolics in the wine. Phenolics develop as the grapes ripen (see photo), so there is a big vineyard-based element to the phenolics that appear in the final wine. But there are also many things the winemaker can do in the cellar to manage the phenolic profile of their finished wine . . . hence the value of a panel such as the one I was on. Of course, there's a lot more to polyphenolics than that, but for the purposes of this blog (and for how consumers experience phenolics), we'll go with that simplification.

Our panel consisted of two leading experts in the analysis and understanding of phenolics: (Dr.) Jim Kennedy, of Oregon State University, and (Dr.) Doug Adams of UC Davis, and two leading Oregon winemakers: Anna Matzinger of Archery Summit Winery, and Lynn Penner-Ash of Penner-Ash Wine Cellars.

Oh yeah, and one wine writer: me.

The first flight of wines were "experiments" from Anna and Lynn. For instance, Anna showed two Pinot noir barrel samples from the 2007 vintage. One was fermented in wood and the other in steel; the object was to see what the differences in phenolic composition were depending upon the type of fermenting vessel. It was an interesting comparison. The steel-fermented wine seemed decidedly fruitier and freshly forward, while the wood-fermented wine had more detectable tannin and carried a greater sense of weight in the mouth.

That is pretty much what I "wood" have expected of the wines, and the chemical analysis of the phenolics bore out the sensory impression quite nicely. Anna commented that what she gained in the wood-ferment was greater complexity and depth, but what she lost was a sense of brighter fruit. She was quick to add, though, that both of these approaches would be part of the final blend for her 2007 wines, and were not intended to be examples of wines she would release . . . these were pre-blending samples to illustrate the kind of polyphenolics that resulted from the two fermentation regimes.

Lynn presented two pairs of wines that illustrated some of her experiments as she grappled with the rainy and difficult 2007 vintage. The first was Pinot noir as it was fermented from the field, compared to the same wine with a measured addition of enological tannins. Again, the difference was clearly detectable on the palate, as well as demonstrable by the chemical analysis numbers. Though I found the flavor differences to be negligible, the mouth feel was definitely more grippy with the small tannin addition, and I thought the nose was more complex as well.

Lynn also showed the difference between wine samples that included a Pinot that had been saigneed (bleeding off a portion of free-run juice in order to concentrate the phenolics in the remaining juice), and one that had added tannin and no saignee. And as expected, the differences ran true to form, and true to the numbers.

Each of the wines was accompanied by a chemical analysis done at UC Davis by Wynne Peterson-Nedry (daughter of Harry Peterson-Nedry of Chehalem, who helped organize the panel). In this first flight it was interesting to correlate the phenolic numbers to the experience of the phenolics on the palate. Jim and Doug spoke knowledgeably (as you would expect) about how protein-precipitated phenols helped influence the mouth feel . . . and other such chemically stuff . . .

Frankly, the wine geek in me found it all fascinating and helpful, and even for the assembled winemakers, the comparison trials were informative.

But once the "real" wine people were done with their samples, it became my turn to conduct the second flight of wines: 6 samples of commercially available 2006 Pinot noirs selected to illustrate a range of phenolic characteristics in finished wines . . .

. . . of which more in my next post.