Featured Research

from universities, journals, and other organizations

Special yeast reduce alcohol, improve wine

Date:
January 16, 2014
Source:
American Society for Microbiology
Summary:
A team of researchers has taken a giant step towards controlling a growing problem in the wine community. They have identified special yeast that produce a lower level of alcohol, helping to preserve the flavor.

A team of Australian researchers has taken a giant step towards controlling a growing problem in the wine community. They have identified special yeast that produce a lower level of alcohol, helping to preserve the flavor. Their research is published ahead of print in the journal Applied and Environmental Microbiology.

The alcoholic content of wine has crept gradually northward in the last 10-15 years, from 12-12.5 percent to beyond 15 percent. What might sound trivial to aficionados of hard liquor is seen by some oenophiles as a disturbing trend, threatening the flavor and character of some wines. That, plus issues of public health, as well as taxes (in some countries, on alcoholic content), have created a need for approaches to lowering alcohol content.

The investigation began with a systematic screening of non-Saccharomyces yeast as a means of achieving such a reduction, says corresponding author Cristian Varela of the Australian Wine Research Institute, Adelaide, South Australia. The investigators evaluated 50 different isolates from 40 species and 24 genera for their capacity to produced wine with reduced ethanol concentration. They chose the most successful of these yeasts, Metschnikowia pulcherrima AWRI1149, for experiments in which it was set to work separately on Chardonnay and Shiraz musts.

Once the slower-growing Metschnikowia yeasts had consumed 50 percent of the sugar, S. cerevisiae were added to the mix to complete the process. This "sequential inoculation" reduced the alcohol content in Shiraz from 15 percent to 13.4 percent (and somewhat less in Chardonnay). Controls not inoculated with non-Saccharomyces strains did not produce reduced alcohol content, according to the report.

"The reduction isn't all that great, but it's in the right direction, and with more work, they might get that even lower, perhaps by letting the non-Saccharomyces yeast go longer before you throw in the Saccharomyces, says Alan Bakalinsky, of Oregon State University, Corvallis, who was not involved in the research.

This reduction in alcohol will be of great benefit to the industry says Louisa Rose, of Yalumba and Hill-Smith Family Vinyards, Angaston, South Australia, who is also a director of the Australian Wine Research Institute. "It is using techniques -- sequential fermentation -- that can easily be used in the winery on a commercial scale."

Previous studies investigating the effects of non-Saccharomyces yeasts on alcoholic fermentation have focused on few species and been concerned principally with the formation of the flavor compounds that might impact negatively on wine quality. None of these led to reductions in alcohol content as substantial as those he reported, says Varela.

The rise in alcohol content in wine has resulted from later harvesting of red grapes. This allows the tannins -- responsible for astringency and bitterness -- to soften, and in some varieties, it helps minimize the presence of off-flavors, like methoxypyrazines (green pepper/asparagus sensory notes.) But on the downside, the boost in alcohol content reduces aroma and flavor intensity, as well as otherwise impairing the oenological experience. Reducing the alcohol would enable the best of both worlds.

It would also reduce consumer costs in countries where alcohol consumption is taxed, and accede to national and international public health recommendations to lower the alcohol content of alcoholic beverages, such as wine.


Story Source:

The above story is based on materials provided by American Society for Microbiology. Note: Materials may be edited for content and length.


Journal Reference:

  1. A. Contreras, C. Hidalgo, P. A. Henschke, P. J. Chambers, C. Curtin, C. Varela. Evaluation of non-Saccharomyces yeast for the reduction of alcohol content in wine. Applied and Environmental Microbiology, 2013; DOI: 10.1128/AEM.03780-13

Cite This Page:

American Society for Microbiology. "Special yeast reduce alcohol, improve wine." ScienceDaily. ScienceDaily, 16 January 2014. <www.sciencedaily.com/releases/2014/01/140116162214.htm>.
American Society for Microbiology. (2014, January 16). Special yeast reduce alcohol, improve wine. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2014/01/140116162214.htm
American Society for Microbiology. "Special yeast reduce alcohol, improve wine." ScienceDaily. www.sciencedaily.com/releases/2014/01/140116162214.htm (accessed October 2, 2014).

Share This



More Plants & Animals News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Dolphins and Turtles Under Threat in Pakistan

Dolphins and Turtles Under Threat in Pakistan

AFP (Oct. 2, 2014) — The turtles and Dolphins of Pakistan's Indus river - both protected by law - are in a fight for their survival as man's activities threatens their futures. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
'Harvest Break' Endures in Maine Potato Fields

'Harvest Break' Endures in Maine Potato Fields

AP (Oct. 2, 2014) — Educators and farmers are clinging to a tradition aimed at giving farmers much-needed help in getting potatoes out of the fields and into storage before the ground freezes in the nation's northeast corner. (Oct. 2) Video provided by AP
Powered by NewsLook.com
Attacking Superbugs

Attacking Superbugs

Ivanhoe (Oct. 1, 2014) — Two weapons hospitals can use to attack superbugs. Scientists in Ireland created a new gel resistant to superbugs, and a robot that can disinfect a room in minutes. Video provided by Ivanhoe
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins