by Jeff Miller of Artisan Family of Wines (Seven Artisans, Sly Dog Cellars, Red Côte Rosé)
There’s an old Dan Hicks’ song, “How Can I Miss You When You Won’t Go Away”. Submerged cap fermentation seems to have taken on a similar life of its own. At any rate, I think this will be the last post on the subject, at least for awhile.
What brought this subject back to life was a study I found published in 1961 in which Prof. Ough at UC Davis ran some tests on a submerged cap versus traditional pumpover and punchdown fermentations, and failed to obtain the increased color that I did. In fact, he concluded that submerged cap fermentations resulted in less color, not more. I don’t have a clue as to why he obtained results so different than mine. At first I thought that maybe I’d done something very wrong since UC Davis, having the advantage of better equipment and real scientists, must be right. But the more I thought about it, the more sure I became of my results, for a number of reasons. For one, the tests that both Prof Ough and I conducted were similar in nature, so UC Davis probably didn’t have much of an advantage in this regard. Second, on many of the samples, the extra color was visually apparent to the naked eye, so it’s hard to question spectrometer results to the same effect. It’s possible that there was some difference in how Prof. Ough and I did our fermentations, but if there was anything that would account for our different results, I sure couldn’t figure out what it was. So, at this point, it’s something of a mystery.
Prof. Ough also found that the cap temperature of the submerged cap was higher than in traditional fermentations, something I find quick surprising. Since I didn’t think to try to measure the temperatures in the caps (both submerged and non-submerged), I have no evidence to question this conclusion, though next year I think I’ll try to remember to take some temperature readings, and see if I agree with him.
If anyone else has tried to do this sort of color analysis, I would appreciate any feedback they might provide.
For those interested, the Ough study can be found at http://www.ajevonline.org/cgi/reprint/12/1/9
I also found these web pages in which the use of submerged caps was discussed:
Sangiovese: Varietal Focus
http://www.winemakermag.com/stories/vf/article/indices/38-varietalswine-styles/614-sangiovese-varietal-focus (discusses the use of submerged cap fermentations at Viansa Winery for their Sangiovese)
Harvesting in the Priorat: Fermentation I - Maceration Techniques
Gur-Arieh’s submerged cap fermentation tank