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 September 22, 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 September 22, 2014).

Share This



More Plants & Animals News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
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:
from the past week

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