Ralph Kunkee

Wines & Vines, July, 1998 by Larry Walker

In almost three decades of teaching and research, Kunkee, who retired from fulltime teaching in 1991, achieved enough significant accomplishments to fill several closely-written sheets of paper, most having to do with better control over the microbiology details of winemaking operations. Here are a few highlights that in his estimation have been of some importance in the wine world, listed in roughly chronological order from the time his teaching career began at Davis in 1963, until his retirement:

* The importance of the use of wine starter cultures was emphasized, especially when active dry wine yeast preparations began to be commercially available;

* Research of the various yeast strains showed that the fermentation vigor was dependent both upon the nutrition components of grape must and also upon the genetic characteristics of the strains;

* With respect to flavor, a mutant of wine yeast was induced and selected which produced no isoamyl alcohol, an important component of fusel oil, from sugar. The employment of this mutant allows a more economic and better flavored production of wine spirits and brandies;

* Also with respect to flavor, research with wine yeast and with elemental sulfur showed that proper viticulture practices that avoided the use of sulfur as a fungicide later in the grape ripening season are the single most important methods to control formation of hydrogen sulfide during fermentation;

* The use of malolactic bacterial starter cultures in commercial production of red wine was demonstrated and its use encouraged, making this procedure currently one of the most visible technical advances in the California industry. This usage brought about better control of malolactic fermentation and also changed normal completion of it from mid-spring to near the end of vintage and allows the winemaker the option to begin finishing red wines months earlier than traditionally;

* Simplified the procedure of the detection of malolactic fermentation;

* Fundamental research on malolactic bacteria led to an explanation for the surprising stimulation of the growth of these bacteria in the presence of malic acid. Research demonstrated that the malolactic enzyme was a single enzyme, not two as previously believed;

* Applied research led to the first identifications of the isolations of spoilage yeast Brettanomyces and Zygosaccharomyces in California wines;

* Early research on and demonstrations of the practicality of sterile filtration and bottling, and the insistence on its use, were made for the prevention of microbiological spoilage in bottled wine;

* A research effort, which has gone nowhere, at least in the U.S., but some think that it should have gone somewhere, was the development of practical procedures for the production of sparkling wine by continuous fermentation;

* Not a research accomplishment, but a significant activity, has been the reception, care, supervision of maintenance and expansion of the UCD Enology culture collection of wine related yeast and bacteria;

* Finally, last but not least, has been the pleasure of guiding many, many enology students (and being guided by them) through the wonderful world of wine microbiology - that is, through the course Viticulture & Enology 217. At last count, the number of students successfully completing this class - and who are out there somewhere in the wine world, is 781.

"I want to acknowledge the important role former and present graduate students and colleagues, and their graduate students, and the technical and administrative personnel both inside and outside the department, had in making these accomplishments real," Kunkee said. "Special acknowledgment should goal so to Marilynn Vilas, my most recent staff research associate."

Looking to the future, Kunkee believes that one of the most encouraging developments in California winemaking is the interest in the science of viticulture by winemakers. "There have been tremendous strides made in the vineyard and science is king," he said. "On the other hand, it is too bad that some of the same people who acknowledge that (science is king) in the vineyard, have difficulty bringing science into the wine cellar."

He is also encouraged by the growing interest in sometimes overlooked or underused varieties of grapes, such as Viognier. "1 hope that interest will continue."

Kunkee said he also believes there will be a tendency to let the varietal flavor come through in the wines, specifically in the case of Chardonnay. "I think the apparent desire for overoaked Chardonnay has been foisted of the public. Now I am not a marketing person and I'm glad I don't have to make my living by doing that, but I do believe the Chablis-style of Chardonnay will become more popular," he said.

"I think it would be wonderful, too, if the California industry could get together the way the Australians have for wine promotion. It just seems a shame that doesn't happen."

Kunkee seems to be thoroughly enjoying his new leisure time, but he is still ready to wade into the fray on topics like wild yeast and, from his long perspective, acknowledge both sides of the argument, quoting the novelist Lawrence Durrell, "Life is made dull by the authority of bald reason."