14 minute read
Could glycoside extracts from grape marc provide a flavour boost to NOLO wines?
Promising research into the ability of glycosides extracted from grape marc to boost floral characters in wine could become an addition to winemakers’ toolkits in their quest for producing good quality no and low alcohol wines, writes Sonya Logan.
Each vintage the Australian and New Zealand wine industries collectively discard a significant amount of flavour potential in grape skins generated from white wine production. One such flavour compound is monoterpenes, which although are present in all grape varieties, are particularly pronounced in Riesling, Gewurztraminer and Muscat varieties. Monoterpenes contribute to ‘floral’ or ‘citrus’ characters and are mostly stored in grapes as odourless glycosides. During winemaking or storage and the act of wine tasting, the glycosides are broken down and released.
The potential of extracting these glycosides from grape marc and using them to legally add flavour to other wines has recently been explored by researchers at the Australian Wine Research Institute. They developed a technique designed to be carried out in wineries that treated grape marc to extract glycosides. Because marc also contains compounds that can increase undesirable wine flavours, such as bitterness, the technique involves purifying the extract to remove the bitter phenolics, resulting in an extract rich in monoterpene glycosides but with no aroma.
The researchers used an extract, derived from Gewurztraminer, to supplement Riesling and Chardonnay juices before fermentation and at bottling. The addition of the glycosides from the grape marc did indeed increase the fruity and floral aromas, flavours and aftertaste in both the Riesling and Chardonnay wines, establishing the potential of the process to utilise flavour otherwise lost in grape marc every vintage. It came as something of a surprise to find out that adding the extracts either pre or post fermentation did not influence the effectiveness of the extracts. extract of a flavour precursor in preferment versus post-ferment that there would be quite a significant difference between the flavour outcome in those wines because one had the extracts added when the enzymes present during fermentation were going to be active, while the others didn’t,” explains senior research scientist Josh Hixson, who had previously researched the effect of feeding grape marc to cows on their methane production. “As it turns out, there really wasn’t a great difference between the pre or post
The potential of extracting glycosides from grape marc and using them to add flavour to other wines, particularly no and low alcohol wines, is being explored by researchers at the Australian Wine Research Institute.
Marc is collected at a winery by AWRI researchers for the purposes of extracting the glycosides from it (left) and the extraction process set up in a winery (below).
Josh Hixson
fermentation additions. The interesting thing about that is, if this were to become a commercial product, rather than adding the extracts to a must where you are unsure of the outcome of fermentation, you can do it reactively based on how the wine has turned out post-fermentation. In other words, rather than trying to guess whether a wine is going to have as much flavour as you think, you can wait and see how the wine turns out and then decide whether to add it.”
So, that outcome came as a surprise? “It was a bit of a surprise,” Hixson admits. “There was a firmly held belief that a lot of the reactions we expected were due to fermentation. But the enzymes that are present [during fermentation] can’t be as active as we thought on those types of compounds.” Given not every winery has easy access to Gewurztraminer marc, it was decided to test the effect of monoterpene glycoside extracts from other grape varieties, including both ‘floral’ and ‘non-floral’ varieties, namely Muscat a Petits Grains Blancs, Muscat Gordo Blanco, Riesling, Viognier, Cabernet Sauvignon, Chardonnay, Sauvignon Blanc, Semillon, Shiraz and Verdehlo. “We just wanted to cover off on some of the other varieties that may not be at the front of people’s minds in terms of monoterpenes and that floral aroma, just in case there was this unexpected pile of glycosides that we were throwing out,” Hixson explains. However, that didn’t prove to be the case. “We came back full circle to the Muscat varieties that were high in glycosides that produce extracts that are very rich in monoterpene glycosides and produce a lot of flavour when stored in wine. This means that if you are going to take grape marc as an input for producing a flavour extract you would ideally want it to be
either exclusively Muscat or varieties like Gewurztraminer and Riesling which are quite floral as well.”
Potential hurdle
This finding alluded to a potential hurdle in the adoption of extracting monoterpene glycosides from grape marc by wineries — how do they source sufficient quantities of marc with the most ideal concentrations?
While the exploration of other varieties for monoterpene glycoside concentrations was being carried, the researchers reached out to industry to determine its appetite for enhancing wine flavour broadly and using the marc-derived extracts specifically. To gain a full understanding of the likely uptake of the extraction and purification process by industry, Hixson and his research colleagues took part in the CSIRO’s ON Prime program which helps research teams like his determine who can benefit the most from their research.
“We asked wine producers how they felt about wine flavour and aroma and the consistency that they achieve. And whether they felt they had the tools at hand to manipulate a flavour profile if that’s what they wanted to do,” Hixson explains. While many wine producers are happy to let their wines reflect the vineyard and vintage conditions of any given year and therefore have little interest in modulating wine flavour, others, particularly larger commercial wine companies, indicated they were interested in regulating it to meet stylistic targets. And the products that those companies nominated as likely to benefit the most from flavour enhancement was low and no alcohol (aka NOLO) wine which is attracting growing interest among consumers and producers alike. “There is a technical challenge in taking the ethanol out of wine while leaving in a lot of the things that you want that ethanol delivers,” says Hixson. “[The AWRI is] about to ramp up quite significantly its understanding of NOLO products and the things we have at our disposal to change the texture, the flavour and the colour of wine. Wherever we can make improvements we’ll try.” And it is the potential of glycoside extracts to generate those improvements which is now in the process of being trialled by the AWRI. As part of the trial, monoterpene extracts have been added to model conventional wines with different alcohol levels, specifically 0%, 1%, 5% and 12%v/v, to determine their effect on flavour. Other commercial additives are also being trialled to assess their effects on no and low alcohol wines.
“’We’re looking at what is available at our fingertips to be able to help boost no and low alcohol wine. The monoterpene glycosides are also in our scope. If we can show that they’re beneficial to the product, that would definitely be a big step towards demonstrating their usefulness by industry,” Hixson points out.
Irrespective of these outcomes, the ON Prime program revealed the cost of producing the extracts inhouse by
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Qualia Wines senior white winemaker Pia Merrick.
wineries was likely to be a stumbling block in its uptake. “What we found was that the decision by producers to use additives in their wines is extremely cost sensitive. The absolute most they want to pay is a couple of cents per litre. And with the cost and energy intensive nature of obtaining these extracts, we got to the point where we had to admit that they may not have application in the current climate using existing technology,” Hixson says. He adds if there is sufficient industry interest in use of the extracts, from a logistics and cost perspective their production would likely have to fall to a facility where marc from various producers could be aggregated. Such a facility could also process the marc to extract other substances, such as ethanol and tartaric acid.
Two Australian wine companies keeping a watchful eye on the AWRI’s investigations into the potential use of glycoside extracts to enhance NOLO wines are Treasury Wine Estates (TWE) and Qualia Wines. Iain Jones, TWE’s head of R&D, quality and compliance, said it was “pleasing to see the AWRI produce this groundbreaking research”. “The no and low alcohol category has grown rapidly over the past few years,” Jones notes. “As the product range expands, consumers are becoming more interested in no and low alcohol wines that replicate the flavour, mouthfeel, and varietal characteristics of their favourite wine.
“Our research has shown that taste is one of the biggest barriers to purchase, with 20% of consumers surveyed saying that they don’t like the taste of no and low alcohol wine,” he adds. In 2021, TWE launched a portfolio of zero alcohol wines under its Wolf Blass label and offers no and low alcohol products under the Lindeman’s and Squealing
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Pig brands. Jones says there has been a “positive consumer response so far” to those wines with plans afoot to introduce more wines in the NOLO category across the company’s suite of brands. Qualia Wines produces its own brands and makes bulk and bottled wines for third parties out of its operations at Irymple in Victoria. Pia Merrick, senior white winemaker, says when she first learned about the AWRI’s investigations into marc glycosides back in 2019 she was “inspired” about the possibility of using marc to boost wine flavour. The following year she got in touch with the research team to explore the possibility of producing the extracts at Qualia from Gordo marc which would be used in wines that would subsequently be made available for tasting by local winemakers. Unfortunately COVID-19 upset those plans, but Merrick remains keenly interested in the results from the AWRI’s work.
Merrick says Qualia has had a number of its clients inquire about purchasing reduced alcohol and no and low alcohol table wines. However, those customers have expressed concern about consumers’ acceptance of the flavour of such wines. “Recent market requests have been towards lower alcohol wines and alcohol free wines. Qualia Wines is looking into both of these categories and could see an opportunity to increase the aroma profile, flavour and aftertaste with products like the marc-derived extracts,” Merrick says. “At this stage Qualia Wines doesn’t see itself extracting the marc but we are certainly interested in following the further studies and trials of this product. If Qualia Wines was to purify the marc it would most likely be a variety like Gordo. [But] we would also be interested to see how other aromatic varieties would behave.
“We would like to see trials of the glycoside extracts in bottled products that have been in the bottle for 3, 6 and 12 months. Also, it would be good to see trials where wine is stored in ‘bag-inbox’ environments.”
Merrick cautions the additives couldn’t cost more than a few cents per litre for their use to be financially justified. “The cost would need to fit in the category of other wine additives like oak chips or tannin type additives,” she clarifies.
She emphasises the additives would also have to comply with food safety management systems and certifications. “We’ve just upgraded from ISO 22000 to FSSC 22000 because our customers were requesting it. Anything we add to wine, every single droplet, needs to be approved under the FSSC 22000 system,” she says.
Pia Merrick
Right: Treasury Wine Estates’ head of R&D, quality and compliance Iain Jones.
Below: Senior research scientist with the Australian Wine Research Institute, Josh Hixson.
The Rise of NoLo
The past few years have seen a dramatic shift in innovation in the no/low-alcohol (NoLo) sector due to a significant increase in demand for alternatives to alcoholic beverages.
According to research conducted by the Endeavour Group, the NoLo sector has had 78% growth with younger customers being the most engaged as it aligns with their healthy lifestyles and a desire to moderate alcohol consumption. “Although the NoLo market has focused mainly on beer alternatives we are finding significant growth in the wine sector. The COVID lockdowns seemed to genuinely change consumer’s drinking habits and we have noticed an increase from our customers in the uptake of services we offer at Vinpac to assist in the production of NoLo wine,” said Adam Niederer, national sales manager of Vinpac International.
“JMB Beverages brand Edenvale has been leading the way in this space since 2006. They saw an opportunity within the market for a sophisticated beverage for those who want to enjoy the wine drinking experience without having to consume alcohol,” Niederer said. “As the leading producer of alcoholremoved wines in Australia, maintaining the integrity of our product is paramount, said Michael Bright, owner of JMB/ Edenvale Beverages. “Using our advanced alcohol removal technology, we produce dealcoholized wines that must be bottled in a sterile environment to protect their sensitive nature, and we have relied on Vinpac to provide this service since we first launched in 2006.
“Edenvale was founded on the belief that people across Australia and globally should have access to premium Australian alcohol-removed wines that offer the same taste, aroma, complexity and variety of traditional wines. We have worked with Vinpac International for many years to bring these innovative wines to our consumers,” Bright said. Vinpac International has been proud to be able to support the Edenvale vision and has adapted services depending on what each wine has needed. The services provided by Vinpac in the NoLo sector is as follows:
Lo or No-alc using a de-alcoholisation
process – for a reduction or correction of alcohol Vinpac collaborate with VAF Memstar who utilise their portable unit at the Vinpac Angaston site to undertake the required work. However, if a wine requires total removal of alcohol then it needs to be completed elsewhere before delivery. The level of de-alcoholisation required will dictate the best equipment for the purpose. Lo or no-alc by blending – ‘wine-like’ product – if a customer provides Vinpac with components to blend or ‘create’ their no or lo-alc product, this can be done on site.
Juice - Vinpac have been handling juice products for customers over many years - grape, apple, mixtures of various different juices and concentrates. As part of processing these products Vinpac also offers filtration, cold and heat stabilisation (if required), the addition of other additives, dissolved oxygen and carbon dioxide adjustment. Vinpac is not just seeing an uptake of NoLo options through bottling but also through our packaging division VI Packaging and Pinnacle Drinks. “We work with a lot of companies looking for unique packaging for flavoured teas, kombucha and other non-alcoholic beverages,” said Kate Salway, national sales manager at VI Packaging/Pinnacle. “NoLo beverages are definitely on the rise, due to their increased presence in supermarket chains, bars and specialist online retailers,” Salway said. For more information about how Vinpac International may be able to help your business, call (08) 8561 0600.
We are passionate about innovation and investment in alternative packaging formats and emerging trends including natural wines, low and no alcohol styles. Together, we deliver trusted solutions our customers love.
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