Taste a hint of last year’s wildfire in that merlot?

UBC researchers map smoke taint in wine grapes

Grape growers have long sought to protect their crops from the effects of wildfire smoke and new research from UBC’s Okanagan campus is giving them new insights.

In a recent study, researchers at UBC Okanagan and their industrial partner Supra Research and Development examined what happens to wine grapes after they are exposed to wildfire smoke. They determined that volatile phenols—chemicals in the smoke that can give wine an off-putting smoky flavour and aroma known as smoke taint—are absorbed quickly and remain in the grape long after the smoke has cleared.

“The biology of how wine grapes respond to smoke exposure is poorly understood,” said Wesley Zandberg, assistant professor of chemistry at UBC’s Okanagan campus, in a press release.

READ MORE: Wine bootcamp, anyone?

“Winemakers know that grapes grown in smoky conditions can lead to smoky-flavoured wine although the grapes themselves taste normal, and how or why this happens has largely remained a mystery.”

To better understand the process, Zandberg worked with PhD student Matthew Noestheden and research associate Eric Dennis to collect samples of Cabernet Franc grapes after exposing them to simulated forest fire smoke. They then tested for the presence of volatile phenols at several time points after smoke exposure and in wine made from the same grapes.

“We found that once the grapes were exposed to smoke, the volatile phenols were rapidly metabolized by the grape and stored, in part, in a sugary form that we can’t taste or smell,” said Noestheden. “Once there, the concentrations remained unchanged in the grape throughout its development. Only when the grapes were fermented into wine could the smoky-flavoured volatile phenols be detected.”

READ MORE: Millennials closing in as B.C.’s biggest wine drinkers

To ensure the experiments mimicked the real world as closely as possible, Zandberg, Dennis and Noestheden were careful to expose the grapes to smoke from locally sourced fuels, including Ponderosa pine and leaf litter from local forests.

“The composition of smoke can vary wildly depending on regional vegetation,” said Noestheden. “For example, Australian wildfires predominantly burn species of eucalyptus and wild grasses, which is very different from what we’d see in western North America. To benefit the local wine industry, we wanted to make sure we measured how grapes were reacting to ‘local smoke’.”

In addition to measuring volatile phenols in grapes over time, the team also tested whether overhead irrigation, a potential strategy to mitigate the effect of smoke exposure on grapes, was effective in reducing their presence.

“We washed the berries to simulate the use of an overhead irrigation system and we were surprised to learn that it didn’t seem to affect the concentration of volatile phenols at all,” said Zandberg. “The good news is that our study provides all the procedures and protocols necessary to test new mitigation strategies in the future. We intend to pursue these with our industrial partner, Supra Research and Development.”

Zandberg also said that they discovered something they weren’t expecting.

While the amount of free volatile phenols that can be detected by taste and/or smell increased in the wine when compared to the grapes, so too did the sugary forms, which are not detectable by taste or smell.

“We expected to see the sugary forms of the volatile phenols decreasing in the wine as the free versions increase, the latter being directly produced by the former, but instead we saw them both increassaid Zandberg. “That means something else is going on and the story may be more complicated than we think.”

To report a typo, email: edit@kelownacapnews.com.



kmichaels@kelownacapnews.com

Like us on Facebook and follow us on Twitter.

Just Posted

Spike in Jaffray bear calls cause for concern

In 2018 there were 38 calls about bears spotted in the Jaffray area, compared to one call in 2017.

Snow on the way for Elk Valley

Winter weather advisory issued for East Kootenay with up to 15cm of snow expected over the next week

Snow removal still an issue for mobility challenged in Fernie

Disability advocate sees little improvement in sidewalk clearing; City promises to review policy

Sparwood trails community growing

Sparwood Trails Alliance grows trail network, membership; hosting fatbike event February 2

Huge demand for youth funding in the Elk Valley

Emily Brydon Youth Foundation overwhelmed by 2018/19 winter applications from local youth

B.C. opioid crisis to get same world-renowned treatment approach as HIV/AIDS

A program that focuses on treatment as prevention will roll out Jan. 17

In limbo: Leftover embryos challenge clinics, couples

Some are outright abandoned by people who quit paying storage fees and other couples struggle with tough decisions

BREAKING: Jury finds man accused of killing B.C. girl, 12, guilty

Twelve-year-old Monica Jack disappeared in May 1978 while riding her bike along a highway in Merritt, B.C.

B.C. government extends coastal log export rules for six months

Premier John Horgan promises reform at loggers’ convention

B.C. pair accused of ‘honour-killing’ in India to be extradited within days

Malkit Kaur Sidhu and Surjit Singh Badesha are accused of conspiracy to commit murder

OPINION: Jaffray bear meeting good first step, but not enough

A large number of individuals attended the grizzly bear meeting in Jaffray… Continue reading

Netflix rejects request to remove Lac-Megantic images from ‘Bird Box’

At least two shows on Netflix’s Canadian platform briefly use actual footage of the 2013 tragedy

FOCUS: Canada’s revamped impaired driving law brews ‘potential for injustice’

There must be ‘trigger’ for cops to come knocking, Surrey MP says

Barack Obama to speak at Vancouver event

Former U.S. president will speak with board of trade in March

Most Read