Normal filtration involves the wine being forced directly through a membrane, but this results in pores eventually clogging. With cross-flow, also known as reverse osmosis, it’s possible to remove the alcohol, along with some water and organic acids, but leave all the other flavour components in the wine.
The best technology for this, however, is spinning cone. In this process, a series of cones rotates rapidly, and this centrifugal force turns the wine into a film. In the first step, nitrogen is introduced and a fraction is taken off that consists of the aromatic molecules. Then the temperature is increased and the next fraction, which consists of mostly alcohol. The remaining de-alcoholised wine is then recombined with the aromatic fraction.
The spinning cone column, developed by Conetech, has been integral to the production of reduced alcohol wines, and also the no-low alcohol wines. “We have been very much involved in the creation of these products,” says Conetech’s Dann, “as our state-of-the-art technology for conservation of all the fragile aroma/flavour compounds is essential to the task.” He thinks good quality lower-alcohol wines can’t be achieved just in the vineyard, and that it represents a serious winemaking challenge. “Many wines are simply not suitable for ‘conversion’ to a reduced alcohol role. Counter-intuitively, ripe fruit with really good flavour development is essential (in spite of correspondingly high initial sugar and consequent alcohol), and so is planning for balance after the subtraction of alcohol. That means selecting and blending wines with relatively low phenolics so that the balancing effect of alcohol is not missed in the final product.”
But if producing good lower-alcohol wines is a challenge, making tasty no-low wines is even more tricky. “No matter what dealcoholisation method is used, the wine is so completely ‘gutted’ that some delicate reconstruction is called for,” says Dann.
The breakthrough for no-low alcohol wines came largely through the work of one company. Spanish giant Torres has achieved great success with its Natureo range. “The trend began almost 10 years ago with the launch of the first really delicious non-alcoholic wine brand, Natureo, from Miguel Torres,’ says Dann. As with other products of its kind, Natureo isn’t completely alcohol free (it’s technically very difficult to eliminate all alcohol) and so is labelled 0.5% alcohol, although the actual alcohol level will be lower. Dann thinks Natureo’s success – sales are now around the million case mark – stems from both using the spinning cone and also because Torres took the winemaking side seriously. “The project team – led by Mireia Torres Maczassek – worked for more than three years on the project,” says Christoph Kamuller of Torres. “The reason it took so long is because it’s not so easy to make a de-alcoholised wine.”
AROMA BALANCE
Kamuller adds: “In the case of de-alcoholised wine the equipment is extremely important, because by reducing alcohol the aroma balance is profoundly altered. People sometimes forget that ethanol is the second most important component in wine after water. Therefore we tested several de-alcoholisation methods. We found that the spinning cone column retained the maximum of the original organoleptic characteristics.” The success of Natureo has prompted other players to follow suit, such as Les Grands Chais de France and Zimmerman Graff, as well as many smaller producers. Conetech is providing services to many of them and says that the volume through its Spanish plant doubled in 2017 and looks set to double again in 2018.
