Effect of Copperoxychloride on the Fermentation of Must and on Wine Quality

Abstract

A Chenin blanc and a Colombar vineyard was sprayed with copperoxychloride (CuOCI) in different spraying programs. A laboratory trial was conducted where copper in different concentrations was added to grape must and fermented. Copper concentrations were determined in musts and wines, fermentation curves established and wine quality assessed. Results show that spraying a vineyard with CuOCI for 5 or 6 consecutive sprays up to 14 or 3 days before harvest respectively caused copper concentrations of 13-44 mg// in the settled musts. Spraying a vineyard at 14 + 7 + 3 days before harvest yielded a must with a copper concentration of 16 mg//. These musts as well as a must to which 10 mg/ I of copper was added, underwent slower fermentation than their respective controls. Wine quality was seriously impaired. It is concluded that the closer to harvest the last copper spray is applied, the more problems will be encountered.

Chemistry of copper in white wine: a review

“…The sources of copper (Cu) in grape juice and wine have been well documented. Although the application of Cu‐based vineyard sprays can lead to a carryover of residual Cu from the surface of the grape into the fermentation, depending on rate and timing of application as well as weather conditions (Tromp and de Klerk , García‐Esparza et al. , Provenzano et al.…”

“…Thus the Cu from vineyard sources is significantly decreased with the removal of yeast cells during clarification of the wine (Hsia et al. , Tromp and de Klerk , Junghans and Straube ). Some bacteria also have the potential for removal of Cu (Schut et al.…”

What’s in organic wine consumer mind? A review on purchasing drivers of organic wines

“…It has been shown [102] that from 10 mg/l it inhibits fermentation, as do agrochemicals residues, but often this is compensated for in treated wines by adding significant amounts of modified yeasts. This is a common practice in wines when fungicides are applied in the vineyard and detected as major pesticides in non-organic wines [60], since most natural yeasts are killed by fungicides.…”

A New pH-Dependent Macrocyclic Rhodamine B-Based Fluorescent Probe for Copper Detection in White Wine

“…The wine industry has become one of the leading sectors in agriculture in Europe (accounting for 60% of world production), followed by the United States, Australia, China, and South Africa [4]. Despite its importance in wine production, copper can lead to a deterioration of the quality of wine by either the formation of volatile sulfur compounds, or turbidity formation, or oxidation [5]. Therefore, it is of great importance to be able to carefully monitor and control the copper content in wine samples.…”