One of the biggest reasons wine consumers reject a wine is finding potassium bitartrate crystals (KHT) in the bottle. Three processes are commonly used in the wine industry to prevent post-bottling KHT: cold stabilisation, subtractive techniques which remove one or more compounds involved in KHT and additive techniques using protective colloids or inhibitors such as metatartaric acid (AMT), carboxymethyl cellulose (CMC), mannoproteins and gum arabic.
Additive techniques are generally more tolerant to the sensory qualities of wine, more environmentally friendly and cost less than subtractive techniques. However they have performance, quality, time and cost limitations, and until now there have been limited options suitable for achieving long-term stability in both white and red wines, without the loss of colour and/or positive sensory attributes.
Zenith is a liquid preparation and has numerous advantages over other additives. The secret ingredient is potassium polyaspartate (KPA), a molecule developed by Enartis specifically for tartrate stabilisation of wine.
Potassium polyaspartate (KPA)
KPA is molecule shown to be effective for tartrate stabilisation of wine. After its discovery through a European research project at Stabiwine, KPA underwent three years of in-depth study to better understand its potential for winemaking. Its efficacy in tartaric stabilisation of wines, combined with its safety for human consumption, led to its approval and inclusion in the OIV International Code of Oenological Practices in 2016. It was subsequently approved for use in Australian wines by Food Standards Australia New Zealand in 2019, and in American wines by the Alcohol and Tobacco Tax and Trade Bureau (TTB) in February.
A recent trial conducted by the Australian Wine Research Institute (AWRI) evaluated the performance of KPA on 13 white, rosé and red wines from various regions in Australia and America treated with Enartis’ Zenith Uno. The wines were tested for tartrate stability over a six-month period alongside untreated (unstable) control wines. All 13 wines were filtered and then treated with the KPA product at a dose rate of 1 ml/litre.
Three of the wines deemed to be protein (heat) stable were also subjected to high temperatures (40 °C) for a 14-day period to mimic the potential effect of heat exposure during shipment of export wines.
KPA performance results
KPA effectively achieved tartrate stability in a range of white, rosé and red wines over a six-month period. In cold hold tests, no tartrate formed in any of the KPA-treated wine samples even after 20 days at -4 °C, up to and including three months post-treatment. The control samples however showed significant tartrate formation after three days at -4 °C.
All wines treated with KPA continued to exhibit tartrate stability with no discernible tartrate crystals formed during the cold hold tests and relatively low conductivity changes, indicating ongoing tartrate stability.
Importantly there were no changes to the colour profile of colour-stable red wines tested and potassium concentration levels in the control and treated wines were comparable across the sample set.
Zenith addresses the limitations of other stabilising techniques. The range consistently performs better than CMC for tartrate stabilisation. As the most effective tartrate stabiliser on the market, KPA has exceptional cost-saving advantages over other options for cold stabilisation. By avoiding the chilling process, there’s less opportunity for oxidation and greater preservation of the wine’s natural acidity. Winemakers also avoid the significant energy and cleaning requirements of traditional cold stabilisation.
Zenith offers a high stabilising capacity over an extended duration with no impact on the wine filterability, no negative interaction with the wine’s colour and no changes in the wine’s sensory properties. It’s added to filtered wines that are protein stable just before bottling. After the addition, the wines are stable for potassium tartrate formation..
Lida Malandra | 082 656 3685 | email@example.com | enartis.com