Efficient tartaric stabilisation of white wine with potassium polyaspartate

Höhere Bundeslehranstalt und Bundesamt für Wein-und Obstbau, Wiener Strasse 74, 3400 Klosterneuburg, Österreich, Austria

^a e-mail: Reinhard.Eder@weinobst.at, www.weinobstklosterneuburg.at

Abstract

The aim of this work was to test the tartaric stabilising effect of potassium polyaspartate (KPA) in comparison to metatartaric acid and carboxymethylcellulose (CMC). Wines of the varieties Chardonnay and Rheinriesling (vintage 2017) were used, furthermore their instability was increased by addition of potassium and tartaric acid. The samples were stored at 2 ^∘C and 20 ^∘C and analyzed after 70, 120 and 175 days. Results showed that the non-stabilized wines exhibited significant precipitations of potassiumhydrogentartrate at both temperatures. The stabilizer CMC could not prevent precipitation in the base wines at 20 ^∘C. For the enriched wines the stabilising effect of CMC was inadequate. Although metatartaric acid gave sufficient stabilization in most variants, in enriched Rheinriesling the stabilising effect lessened after prolonged storage at 2 ^∘C and a tartaric precipitate was detected. Only the wines stabilized with potassium polyaspartate remained blank at all dates and variants and showed no loss of potassiumhydrogentartrate. Control of the residual levels of tartaric acid and potassium after storage confirmed these results. Therefore it can be stated that of the three stabilizers tested, only potassium polyaspartate, even at half the recommended application rate, prevented the precipitation of Weinstein in all variants and thus had the best tartaric stabilising effect.