Interestingly, New Zealand winegrowers have recently launched a NZ$17 million research programme focusing on lifestyle wines, which aims to focus on ways of making lighter-styled wines in the vineyard and through the use of special strains of yeast, rather than reducing alcohol by technological means.
They are convinced the market wants high quality wines at lower alcohol levels and with fewer calories, and believe that, because of its climate, New Zealand is in an ideal position to achieve this. Already, naturally lighter Sauvignons have seen some market success, such as Bella by Invivo.
Technical aspects
This is where we need to look at how lower alcohol wines are made. There are a number of ways of achieving a lighter wine, and some are better than others.
The simplest is to pick grapes early, before they have accumulated much sugar. Some vineyards lend themselves well to this; others don’t. It limits the style of wine you can make, and the results are often lacking in flavour and frequently show undesirable green unripe characters.
The second is to stop fermentation early, leaving a lighter-style wine with quite a bit of sweetness. This can work very well – think Mosel Riesling or Moscato d’Asti – but the wines are sweet and will only satisfy a subset of consumers or drinking occasions.
The third way – and the cheapest – is to add water, flavourings and acid, making a confected wine-based beverage. This is the dark side of lighter wine, and gives the category a bad name. There are plenty of these products around, filling in at the bottom end of the market.
Finally, there are technological solutions for removing alcohol from finished wine. The first and most successful of these is the spinning cone column, which was pioneered by US firm Conetech.
It contains around 40 upside-down cones, half of which are fixed and half spin. In a vacuum environment, the cones spin the wine into thin liquid films and a cool vapour rises off the wine, carrying the volatiles from the liquid. In the first pass, the ultra-light component consisting of the delicate flavours and aromas is carried off and condensed. This is known as the ‘essence’, and it is saved for later, to be recombined with the wine. The second pass takes off as much alcohol as you want to remove. This reduced alcohol wine can be used for blending.
The other technique currently used to reduce alcohol is reverse osmosis, which is a type of filtration system. It works in a similar way to the body’s kidney: while conventional filtration systems have their flow blocked by the filtration membrane, which becomes clogged, here the flow is tangential to the membrane, which helps prevent the pores becoming blocked, although it requires a much larger membrane surface. It’s also known as ‘cross-flow’ filtration.
Expensive process
The consequence of this is that you need lots of very long filtration tubes all bundled together for reverse osmosis, making the system expensive compared with standard filtration systems, although it is still portable and very much cheaper than the spinning cone column.
The cost of the spinning cone machine is around US$1 million, whereas a reverse osmosis machine costs around US$30,000 and is small enough to be moved around, making it possible to do alcohol reduction in the winery.
Conetech is the leading provider of dealcoholisation services, and these come complete with the winemaking guidance for creating successful lighter style wines.
It now has six staff winemakers involved worldwide in California, Chile, South Africa and Europe.
For a while, Conetech made lighter-style wines under its own brand, TFC, but has now reverted to being a service provider. It has spent a lot of time working out how best to make lighter-style wines. “The keys to success in making lighter style wines are selecting the right base wines for removal of alcohol, using the right technology with the gentler spinning cone column, and the final blending and finishing of the wines,” says Jane Milligan, consultant winemaker for Conetech.
