NZ Lighter Wines – The Sensory Side

NZ Lighter Wines – Research Update from the Sensory Side

When Programme Manager David Jordan wants to showcase NZ Lighter’s lower-in-alcohol wines to the media or retailers, often as not he’s going to host a “triangle tasting”.

Tasters are told they will be sampling three selections: two are alike and one is different, and their job is to pick the odd one out. All the wines feature the same variety and the same vintage and are from the same wine producer. The only major difference? The NZ Lighter wine will feature a lower alcohol by volume (ABV) – often as much as 25% to 30% less alcohol. The tasting is “blind”, and participants receive either two glasses of the lighter-strength wine and one glass of the regular – or, conversely, one glass of the lighter wine and two of the regular.

Wine writer and educator Bob Campbell participated in a triangle tasting in early 2019. As he noted in his 23 May 2019 post on The Real Review (therealreview.com), he had little difficulty in identifying the lighter wine selection, in this instance a 2018 Stoneleigh Lighter Sauvignon Blanc, versus its regular-strength counterpart. The surprise, however, was that he preferred it, noting that the lighter wine “was softer than the regular wine, perhaps because it may have been slightly sweeter, although the wine wasn’t obviously sweet.”

Jordan has come to expect responses like Campbell’s, noting that tasters often struggle to tell which wines are lower in alcohol. In early November 2019, at a series of triangle tastings held in Marlborough for visiting Australian media and retailers, once again a number of the participants noted their preference for the lighter Pinot Gris and Rosé offerings.

“The number-one barrier to purchasing a lighter-in-alcohol wine is a preconception on the part of the consumer that the quality and flavour will suffer – sadly, that was true for some of the dealcoholised wines launched by our competitors,” says Jordan. “We believe that lighter wines must offer a ‘like-for-like’ experience that satisfies the flavour and quality expectations of premium wine drinkers – and lighter wines from New Zealand certainly do that.”

New wine category

NZ Lighter (nzlighter.wine) represents a new, multi-branded category – New Zealand wines that weigh in at less than 10% ABV but more than 8.5% ABV (the minimum required in most markets for a product to be called “wine”).

Established through a seven-year research and development initiative led by New Zealand Winegrowers and co-funded under the Ministry for Primary Industries’ Primary Growth Partnership (now part of Sustainable Food & Fibre Futures), NZ Lighter represents the largest R&D initiative ever undertaken by the New Zealand wine industry.

The $17-million programme began in 2014, aiming to position New Zealand as number one in the world for high-quality, lower alcohol and lower calorie wines. The research challenge was to demonstrate how such wines could be produced naturally, giving New Zealand wines a point of difference that appeals to premium wine drinkers.

With contributions from industry levies and direct investment by 18 participating companies*, the programme focuses on all aspects of lower-in-alcohol wines, covering everything from sustainable vineyard and winemaking practices to sensory assessments to market access aimed at driving export growth.

Sensory perception

Market research for the programme has demonstrated that consumers are increasingly interested in wines with lower alcohol levels but don’t want to sacrifice the bright, fresh and fruity characteristics they expect from varietal wines made in New Zealand. In the early days, achieving the right balance of ripe flavours with acid, residual sugar and alcohol proved challenging – particularly with the focus on natural production (as opposed to alcohol extraction techniques).

Enter the sensory assessments commissioned by the programme. Largely run by Plant & Food Research, the trials used a combination of trained assessors and wine experts alongside evaluations from consumers partial to Sauvignon Blanc. The objective was to aid in understanding how the flavour characteristics were experienced and the degree of consumer satisfaction with the wines.

Initially, researchers focused on the sensory characterisation of lighter wines. First up were explorations of NZ Sauvignon Blanc in terms of varied alcohol content, followed by trials to assess the influence of harvest date, canopy trimming at veraison, post-fermentation sugar additions and/or deacidification – all approaches that were being investigated by the research teams involved in vineyard and winery techniques.

The objective was to establish baseline knowledge about the sensory differences between lighter and regular-strength wines – a world first. Using a selection of 2013 commercial wines, researchers altered the alcohol content of NZ Sauvignon Blanc to vary from 9.5% ABV (typical of NZ Lighter wines) through to 12.2% ABV (typical of standard-strength wines).

Compared to a standard alcohol content (12.2% ABV), the lower-in-alcohol wine (9.5% ABV) was perceived by assessors to have decreased sweetness, bitterness, viscosity/full-bodiedness and aftertaste duration. The lighter wines were also perceived to have a less smooth mouthfeel and a reduced perception of heat on the palate. Importantly, however, there were limited effects to the specific flavour characteristics of the lower-ABV offerings and for some of the tasters the flavour was preferred.

Damian Martin, Science Group Leader, Viticulture & Oenology, at Plant & Food Research, observes, “Up until this point, it was widely assumed that lighter wine meant less flavour, so this was a pivotal moment to find that the characteristic New Zealand Sauvignon Blanc flavour expression had been preserved at reduced alcohol levels”.

Brix not the deciding factor

Sensory trials then turned to harvest timing, a key research parameter for the programme. Compared to harvest at standard fruit maturity (around 21 Brix), lower alcohol Sauvignon Blanc wines produced with early fruit harvesting (about 18 Brix) showed less desirable sensory properties. Consistent with expectations, the resulting wines had increased acidity, vegetal and citrus characters, along with decreased sweetness, full-bodiedness, smoothness, length of palate, fruit and mineral flavours.

A revised vine-trimming regime and several post-fermentation interventions were investigated to see if such treatments could compensate partially for the ill effects:

• Compared to grapevine canopies of full size, canopies trimmed to half their size at veraison were shown to result in lighter Sauvignon Blanc wines that had fewer green/vegetal flavours but still retained a relatively similar fruity expression. No other effects on the taste and mouthfeel properties of the wines were found.

• Post-fermentation sugar addition and/or de-acidification also reduced some of the less-desirable effects of lower-than-typical fruit maturity. The sensory effects were similar to those expected from greater fruit maturity at harvest, although they were smaller in magnitude. Once again, the flavour attributes remained more or less unchanged.

Tweaks in the winery

Sensory results have been presented annually at programme workshops for participating companies. Held every October since 2014, the workshops not only highlighted research findings – they often included wines (either research micro-vinifications or commercially produced offerings). Early tastings revealed how sensory effects changed with manipulations in the vineyard or winery. By highlighting the differences, the sensory research helped winemakers to identify and make the adjustments that would enable them to offer the all-important “like for like” experience that consumers were looking for in lighter wines.

Winemakers acted quickly to incorporate these findings into practice. Even in instances where a certain vineyard technique, such as canopy management, was shown to improve some of the flavour characteristics of lighter wines, some winemakers chose to make adjustments in the winery instead. As reported in a previous article in New Zealand Winegrower (“Winemaking Options for Lighter Wines,” Research Supplement, October/November 2018, page 126), at least one company has returned to an early-harvest regime supplemented by a tailor-made approach in the winery – including yeast selections that help to reduce malic acid.

“Sensory trials and analysis have helped winemakers understand that there is more than one route toward the creation of a lighter wine,” Jordan observes. “There is no silver bullet. Participants are using a range of inputs in the vineyard and the winery, thanks in no small part to the contributions from research throughout the life of the programme.”

Consumers respond

Subsequent trials indicated that New Zealand wine consumers’ sensory perceptions were a close match to those expressed by trained and expert assessors. Increases in perceived bitterness, viscosity, drying mouthfeel, heat, and length of palate, along with a reduction in perceived smooth/soft mouthfeel, were associated with increasing wine alcohol content from a lower to a standard level for New Zealand Sauvignon Blanc wine.

In addition, the lower-in-alcohol wines were characterised by consumers as being less complex than wines of systematically increased alcohol concentration. Included in the consumer study was a comparison of wines with low (5.8%) and high (10.1%) residual sugar (RS) levels. Of the two commercial lighter wines tasted, the one with the higher RS content was generally preferred. Consumers enjoyed Sauvignon Blanc wines that were sweeter and with less acidity and bitterness.

Consumer responses to the lighter Sauvignon Blanc wines tasted in the sensory study were positive. The wines were well accepted and were not reported as tasting unfamiliar, suggesting that they were not deemed greatly different from the more familiar regular-strength wines.

Although only a small number of consumers participated in the sensory research, nearly one-third of the group expressed a marked preference for the lighter wines. Those consumers were predominantly female and tended to consume Sauvignon Blanc wines less frequently than the balance of the group.

“Consumer research has consistently supported the findings of the sensory science, and we see this not only in the surveys that the programme has undertaken but also when we offer samples of NZ Lighter wines — the conversion-to-sales rate is better than for other wine styles, indicating the immediate appeal and satisfying a desire for lower-in-alcohol wines,” adds Jordan.

Assessments get an overhaul

Not all of the vineyard or winery trials showed significant differences in the resulting wines when they were put before sensory panellists. In 2017/18, the researchers decided to make a few tweaks of their own by reviewing the assessment criteria for tasting panels and how panelists reported their impressions (see below, “Building a better ballot”).

Research conducted on a set of eight within-brand pairs of commercial 2016/2017 lighter and regular-strength Marlborough Sauvignon Blanc wines generated three key results:

1. By this point, the NZ Lighter Sauvignon Blanc wines had evolved to more closely match their regular-strength counterparts. Despite the two wine styles still being characterised, on average, by different taste and mouthfeel properties, many of the wines shared similar overall sensory properties, including regional typicity.

2. The differences in basic chemical composition between commercial NZ Lighter and regular-strength wines had been reduced, with the pH and titratable acidity of the lower-in-alcohol wines in line with the regular-strength wines.

3. The NZ Lighter Sauvignon Blanc wines now encompassed different sensory variants in perceived aroma intensity, predominating flavours, acidity and sweetness, along with judged levels of freshness, complexity and Marlborough typicity.

Like-for-like experience

Since then, NZ Lighter wines have come of age. Thanks in no small part to the information gleaned through the sensory assessments, participating companies are now confidently crafting wines with lower ABV. They are using a wide range of inputs in the vineyard and the winery while respecting consumer expectations of enjoying the same fresh, fruity characteristics they’d experience in a regular-strength wine of the same variety and vintage.

As Bob Campbell noted in his write-up of the NZ Lighter tasting, “Five years ago I regarded low alcohol wines as a curiosity. Now I see them as a welcome and viable extension to the New Zealand wine list.”

Building a better ballot

In the first sensory investigations conducted in 2014 for the NZ Lighter research programme, a set of lighter and regular-strength New Zealand Sauvignon Blanc wines were evaluated, and the results highlighted profound sensory differences between the two wine styles.

By 2017, however, the sensory properties of commercial lighter wines had evolved to match more closely those of their full-strength counterparts; a similar evolution had taken place in wine chemistry, with the pH and titratable acidity (TA) of the lighter wines becoming aligned with those of regular-strength Sauvignon Blanc wines. Only the alcohol by volume and the higher residual sugar concentrations remained to differentiate lighter wines – and those characteristics were deemed positive attributes.

To ensure that expert panellists were still generating reliable sensory data, researchers revised the sensory test protocols, and, most importantly, reviewed and defined the key sensory attributes to be used to characterise and compare wines in the future.

A new ballot resulted, which reflected the range of terms typically used by wine experts to describe NZ Lighter and regular-strength Sauvignon Blanc wines. Definitions were established for each of the 18 sensory attributes and concepts and were included on the ballot form.

In addition to good varietal expression, “ripe greens”, encompassing a specific category of herbaceous flavour nuances, and “fresh, mouth-watering” acidity were revealed to be key defining characters of Marlborough Sauvignon Blanc wine. Wine experts’ judgments of complexity and Marlborough typicity were also revealed to be exactly the same for NZ Lighter and regular-strength styles.

The revised sensory evaluation ballot and sensory test procedure generated positive feedback from the 15 wine experts who first used it – a number of whom held winemaking roles at companies participating in the NZ Lighter programme.

Andy Petrie, Winemaker at Wither Hills Winery in Marlborough, took part in the process. “Benedicte Pineau, one of the leads on the sensory research team, coordinated a couple of sessions for wine practitioners and sort of ‘mind-mapped’ all of our input. The process was very collaborative, and the really good thing about it was that it was all practitioner focused,” he says.

From there the group prioritised important characteristics, followed by a “calibration session” to nut out the generally understood meanings of terms such as “aromatics” or “herbaceous”. The sessions led to the revised ballot featuring not only sliding scales for a number of terms (see the sample shown in Figure 1) but also “tick boxes” to highlight notable attributes as defined by the team.

“As a winemaker, you develop your own process for tasting wine over time, so it was really useful to break down the tasting process as a panel and take on board each other’s experience,” Petrie adds.

Since then, Petrie has occasionally utilised the ballot for in-house tastings by the winemaking team at Wither Hills because, he notes, “It’s useful to get everyone on the same page about what they’re tasting and what we’re aiming for.”

* The 18 New Zealand wine companies participating in this initiative are: Accolade Wines, Allan Scott Wines, Constellation Brands, Forrest Wines, Giesen Wine Estate, Indevin, Kono, Lawson’s Dry Hills, Marisco Vineyards, Mount Riley Wines, Mt Difficulty Wines, Pernod Ricard, Runner Duck Estate, Spy Valley Estate, Villa Maria, Whitehaven Wine Company, Wither Hills, and Yealands Wines.

This article first appeared in the February/March 2020 issue of the New Zealand Winegrower Magazine.