New process improves the aroma and taste of wines



A retired professor of medicine and amateur winemaker living in B.C.’s Okanagan Valley has invented a ground-breaking new process that uses a high-tech CO2-eliminating membrane to help wineries keep more of the natural aromas in wine during fermentation, producing noticeably better-tasting wines. And it appears the process might be so easy for wineries to incorporate that Dr. Dick Jones’ invention could sweep through the industry and spark a real improvement in the taste of many wines throughout the Okanagan and potentially around the world. 

From his home-based lab and winemaking room in Naramata, Jones says he’s pretty sure his process is a winner, yielding more aromatic, fruitier-tasting wines. 

“It’s very exciting. This could really add value to the wines we make here. I think it will help to bring more awareness of this region to the wine world.” 

 Dr. Jones explains his wine CO2-scrubbing process during a recent experiment with Pinot Gris at Pentâge Winery. Jones isn’t fantasizing about a vague theory. He’s a solid scientist, a University of Alberta professor of pulmonary medicine for 35 years, specializing in lung, cardiovascular, and exercise physiology, and the inventor of nicotine nasal spray to help people quit smoking – one of the U of A’s top inventions ever. 

Not surprisingly, he has gone about the development of his wine CO2-scrubbing process with scientific rigour. He has conducted carefully controlled experiments over three years, including blind taste-tests by experts, as well as chemical analyses of the wines by an independent professional researcher. 

In addition, Jones has the owner of a popular South Okanagan winery on-board as a believer and enthusiastic supporter. 

The “Aha!” moment that launched the project came in October 2012, when Jones noticed the Pinot Gris he had fermenting at home, using grapes harvested from his own small vineyard, smelled exceptionally good. But he realized the valuable aroma compounds he detected were being carried out of the wine by the bubbling CO2, and were lost into the atmosphere, reducing the wine’s flavour. 

Winemakers have struggled with this aroma-loss issue for centuries. Some try to reduce the loss by lower-temperature fermentation, or even what Jones calls “major tampering with the wine” – removing aroma compounds then adding them back in after fermentation. 

“Up to 80 per cent of a wine’s most important aroma compounds can be lost with the CO2 during fermentation,” he says.

As an expert on the human lung’s diffusion and expulsion of CO2, Jones knew at once how he could preserve the wine’s aroma.

“I needed a membrane that selectively allowed the CO2 in the tank’s headspace to escape while leaving the aroma compounds behind,” hje explains.

Searching for a membrane that would work under winery conditions, he found a Norwegian professor who had recently developed a specialized super-thin membrane for scrubbing CO2 from the smokestacks of coal-fired power plants. “It acts like our lungs to get rid of CO?, it’s made of food-grade material, and it works at room temperature and pressure. It is perfect for a winery setting.” 

The membrane’s inventor, Dr. May-Britt Hägg of the University of Science and Technology in Trondheim, Norway, was enthused about the idea of using it to improve wine aroma and flavour, and she supplied membranes for Jones’ experiments. 

When the initial membranes sent for the fall 2013 experiment were damaged in shipping, Jones used CO2-absorbing soda-lime instead, to test his basic theory. With 24 litres of Pinot Gris in an experimental tank and the same amount in a control tank, the CO2 was scrubbed during the first six days of fermentation. An expert wine-taster compared the resulting wines and scored the experimental wine higher for the important attributes of fruity aroma and taste. 

In the fall of 2014, Jones flew to Norway to hand-carry four new 30-by-30-centimetre membranes back to Naramata for a larger, more sophisticated experiment. This time he had experimental and control tanks of about 25 litres each of Pinot Gris and Gamay Rosé. After using the membranes to scrub the CO2 during fermentation, and later bottling samples of each, the experimental wines were compared with the control wines in both an extensive taste-test and a chemical analysis. 

Paul Gardner and Julie Rennie, owners of Pentâge Winery in Penticton, organized a panel of 10 wine experts who blind-tasted and ranked the wines on seven key aroma and taste attributes. As Jones reports, “The tasters rated all seven attributes with higher scores for the membrane-treated wines.” The highest scores were for fruity aroma, complexity, fruity taste, and overall rating. 

Samples of the wines were then analyzed at the University of B.C.’s Wine Research Centre, comparing their levels of dozens of aroma compounds. For the Pinot Gris, there was an average increase of 23 per cent in the measured aroma compound concentrations. This is notable since the membrane was used for only one day during peak CO2 production. For the Gamay Rosé, there was an average increase of 66 per cent in aroma compound concentration. 

“Overall, the taste-tests and laboratory analyses of the experimental wines proved that using the membranes vs. conventional methods left more aroma compounds, improved mouth feel, and retained fruit flavours in the finished product,” Jones says. 

After the testing of the 2014 vintage, Jones knew he had to test his process using commercial winery-quality wine in a real-life winery setting. Paul Gardner, by now a fan of the process, offered his Pentâge Winery as the location. This fall, the headspace in a 1,000-litre tank containing 700 litres of Pentâge’s 2015 Pinot Gris was treated with the CO2 scrubbing, using an improved version of Dr. Hägg’s membrane, this time made up of thousands of hollow fibres encased in a cylinder. 

An identical control tank with 700 litres of the same juice sat next to the experimental tank. Both were fermented at 15 degrees Celsius. Jones and Gardner will run samples of this year’s experimental and control wines through another taste-test and chemical analysis sometime between February and April of 2016 – and they can’t wait for the results, since the wine has already scored significantly higher in initial, non-blind taste trials. 

Gardner looks forward to the possibilities for Jones’ new process. 

“Until now, the loss of aroma during fermentation has been accepted, because there was no easy way to prevent it,” he says. “But Dick’s membrane process makes total sense. The proof is in the pudding – this is definitely a superior wine. I don’t think it will be long before interest in this is worldwide.” 

Both Jones and Gardner say one advantage of the new process is that the equipment for it can be about the size of a suitcase, and the power consumption would be comparable to burning a 100-watt light bulb. Gardner says he will bottle both the control and experimental wines and sell them as a two-pack special-release Pentâge Pinot Gris, and invite feedback from customers. 

Jones knows if his process is absolutely proven to allow CO2 out while keeping aromas in the fermenting wine, he’s onto a real winner. 

“This is the Holy Grail of white winemaking, and there are likely benefits to using the method on red wine fermentation too. People have been trying to do this for a long time.” 

As the months go by, Jones is gaining confidence that his invention will eventually be used to improve the aroma and taste of many wines. One more major indication of the uniqueness of his process is the fact that his patent applications have progressed successfully through the initial review stages. 

“They assess if the idea is novel, if it represents an inventive step, and if it has commercial potential – and it was given high scores on all three factors.” 


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