Low- and no-alcohol wine products – understanding technical and sensory-related challenges and opportunities
Abstract
This project attempted to define the desirable sensory attributes of existing low- and no-alcohol wines or beverages in the market and use this information to support development of wine-like beverages with no- or low-alcohol that can satisfy consumer demands. No- and low-alcohol (NOLO) wines were found to lack some integral sensory attributes that are essential to wine, such as aroma/flavour characters and the textural, warming effect of alcohol. Chemical analysis also revealed that the de-alcoholisation process substantially reduced concentrations of most aroma/flavour compounds. An industry reference group was formed to help gauge interest and understand pain points with the category.
Summary
The category of no- and low-alcohol (NOLO) beverages has shown enormous growth over the past few years. Modern consumers are chasing products that contain all of the aroma, flavour and texture of traditionally produced alcoholic beverages but with little or no alcohol. A small number of Australian wine producers are embracing this market with much success, but the NOLO wine category is lagging behind both NOLO beer and spirits by value and volume, according to sales figures.
This report presents results from a two-year project on the opportunities and challenges associated with NOLO wines. It explores the current market offerings for NOLO wine in Australia, summarising sensory attributes, chemical composition and wine-likeness, as well as the opinions of varied wine industry professionals on where the category sits currently and where research and development efforts should be focused.
The project began by evaluating the NOLO products in the Australian marketplace. One hundred and twenty NOLO products including wine, wine-like products, grape-based products, cider, beer and spirits were evaluated. Initially, the wine and wine-like products were evaluated using a comparison scale, where the taster assessed the likeness to their concept of what wine should smell and taste like (the ‘vinosity scale’). This preliminary assessment tool was used to screen potential products for inclusion in a more rigorous study involving descriptive sensory analysis and evaluating chemical composition. Initial sensory evaluations highlighted the lack of wine-likeness in most products, with the sparkling and white NOLO categories having higher mean vinosity scores than the red NOLO category.
From this group of NOLO products 10 sparkling, 16 white and rosé, and eight red wines were selected for more comprehensive analysis. The products underwent compositional analysis and sensory descriptive analysis. Concentrations of monoterpenes, low molecular weight sulfur compounds, norisoprenoids, oak volatiles, fermentation products, organic acids, glycerol, tannin and colour were all analysed.
The results of the sensory evaluations were then paired with the vinosity scores from the initial product assessments, to highlight the sensory attributes that are most associated with the vinosity of the NOLO wines. For the sparkling wines, vinosity was associated with the sensory attributes ‘astringency’ and ‘banana confection’, but more importantly it was negatively associated with the attribute ‘sweet’, with most of the products being too sweet for the panellists to call wine-like. Another interesting result was that viscosity had neither a positive nor negative association with vinosity, which was surprising, as it was thought that the viscosity of a product would be correlated with its alcohol content, and therefore would affect vinosity ratings. Similarly for the white NOLO products, viscosity was neither positively nor negatively associated with vinosity. However, the attribute ‘warmth’ on the palate was strongly associated with vinosity. The two most wine-like products (highest vinosity scoring) were found in this category and both were Sauvignon Blanc-based products, suggesting that this variety may have good potential for NOLO products. Red NOLO products were less uniform in their sensory assessments with regard to vinosity, with three Shiraz and one Cabernet Sauvignon being the most vinous; however, with scores lower than the white examples. Sensory attributes related to lower quality or faulty wines (‘cheesy’, ‘barnyard’, ‘cooked veg’, ‘bitter’) were negatively associated with vinosity in this segment.
Compositional analysis highlighted one of the big issues in the dealcoholisation process, which is that the removal of alcohol from the product also removes most of the aroma/flavour component. Analysis of 66 different compounds showed that most were removed to concentrations well below their aroma thresholds. Some notable exceptions were 2-phenylethanol and ethyl butanoate, and the thiol compounds 3MH, 3-MHA and 4-MMP, which once again highlights the suitability of Sauvignon Blanc for these types of products, as these thiols are key contributors to Sauvignon Blanc flavour and aroma. The method of alcohol removal also appeared to affect the compositional make-up, with the wines produced using different methods exhibiting slightly different chemical fingerprints.
The product ‘piquette’ was also evaluated, from both a technical production and sensory standpoint. Piquette is a grape-based product made by fermenting rehydrated grape marc. Production of this product is difficult, as the marc is deficient in nutrients and sugar, and once primary fermentation is complete, the low alcohol concentrations do not protect the product microbiologically in the way that traditional wines are protected by their higher alcohol content. Over two years, multiple piquettes were produced from Shiraz, Chardonnay and Sauvignon Blanc marc, with different rehydration regimes, skin contact times, and fermentation on and off skins. These products tended to be between 2.5% and 6.5% alcohol (v/v) depending on the starting sugar level of the original must and the amount of water added at rehydration. Sensory evaluations of the various piquettes highlighted the lack of fermentation nutrients, as most piquette ferments without supplemental nitrogen exhibited reductive aromas and flavours. As a product, piquette shows good potential as a low-alcohol, grape-based beverage, with more savoury, herbal characteristics than traditional wine, and a ‘sustainability’ story regarding the use of what has traditionally been a waste product to produce a unique beverage.
Various flavour and textural additives were also evaluated for their effectiveness in recreating the sensory effects of ethanol in NOLO wines. Additives currently used in the NOLO beer industry were tested in a NOLO wine matrix, with varied results. Glycosides purified from spent grape marc were also evaluated in a NOLO wine matrix, as was the amino acid proline, which has been shown to increase the perception of sweetness in traditional wines. Proline additions were found to enhance flavour and the perception of sweetness in the NOLO wine matrix. The glycosides did not have a perceived effect when added on their own, but when combined with proline the NOLO wines appeared to have more flavour and more perceived sweetness than NOLO wines with just proline added. Additional work in this area is needed, however, there is some potential for the use of both of these compounds as flavour enhancers in NOLO wine production.
An important element of this project has been the formation of and collaboration with an industry reference group. This group involved industry members from across the breadth of the supply chain, ensuring a varied and comprehensive overview of industry wants and needs for NOLO wines. Regular interaction with this group helped to inform the direction of the project and has given confidence that the project deliverables and future projects are addressing the needs of the sector.