Field Testing of Nanofiltration for Tartrate Stabilisation of Wine at Berri Estates Winery
Nanofiltration (NF) is an unproven alternative process technology to cold stabilisation for tartrate stabilising white wines. This process concentrates the wine, instead of cooling, to induce precipitation of tartrate salts. Recent laboratory scale studies by the authors have clearly demonstrated the technical feasibility of NF for tartrate stabilization of commercial white wines. As a consequence, production-scale field testing was undertaken at a major commercial winery, Berri Estates Winery. The testing was performed with a tartrate unstable Colombard wine. The NF system was adapted from an existing membrane system already employed at the winery. The tests were performed as a sequence of processing steps. NF was employed to concentrate the wine causing tartrate crystal formation in the retentate. The use of seeding the retentate, i.e. addition of tartrate seed crystals to accelerate precipitation of tartrate salts, was evaluated. The tartrate crystals in the retentate were separated by centrifugation. The clarified retentate and permeate from NF were blended to reconstitute the wine. Testing was performed to compare the stability and physical and chemical characteristics of the stabilized wine from NF with that produced by cold stabilisation. In addition, sensory testing was conducted to identify whether NF produced any adverse effects on product quality. This paper documents and presents the results from this field tests.