Issue link: http://read.dmtmag.com/i/561374
ou are a winemaker, and y o u r r e d s a r e m i d w a y t h r o u g h f e r m e n t a t i o n . You'd really like to know what's going on in those fer- menters, but it's difficult to assess things by taste at this stage when the wine is still sweet and fizzy. In particular, it would be really nice to know what is going on with the phe- nolics, because they are so intrinsic to red-wine quality. So you send off a sample to a lab, and several days later, you get your results. By then, fermenta- tion has finished and the infor- mation isn't as useful as you'd like it to be. This is why a new technique that allows winemakers to take a quick, simple measurement in their own lab using a readily available instrument, and then d e l i v e r s n e a r- i n s t a n t a n e o u s results about the phenolic com- pounds in the wine, is gaining interest. It's called WineXRay. BY DR. JAMIE GOODE + Traditional phenolics assays require some fairly serious lab work. + In 1999, UC Davis researchers developed a quicker, less expensive phenolics measurement called the Harbertson-Adams assay. + Despite this advance, assay results are not available until after fermentation is finished. + A new testing technique called WineXRay was designed to provide instant results. + Using the company's proprietary analytical system, any winery with a spectrophotometer can get results within a matter of minutes. AT A GLANCE BEYOND TRADITIONAL ASSAYS P h e n o l i c s a r e a c l a s s o f compounds that are of great significance for all wines, but p a r t i c u l a r l y f o r r e d s . T h e y include the tannins and anthocy- anins, but also other molecules such as pigmented polymers, which are complexes between tannins and anthocyanins. Tan- nins can be sensed in wine as astringent or sometimes bitter, and they contribute structure and ageability to red wines. Their sensory properties depend on their molecular composition: They are polymers and their length (the number of subunits in the chain) in large part deter- mines how they are perceived. But tannin perception is also altered by whether or not they are complexed with other mol- ecules, such as anthocyanins, to form pigmented polymers. A n t h o c y a n i n s a r e t h e m a i n agent responsible for color in New Phenolics Testing Technique Promises Faster Results WineXRay can provide data while fermentations are still active ou are a winemaker, and y o u r r e d s a r e m i d w a y t h r o u g h f e r m e n t a t i o n . You'd really like to know what's going on in those fer 6 4 V I N E YA R D & W I N E RY M A N A G E M E N T | S e p t - O c t 2 015 w w w. v w m m e d i a . c o m