Hazes

Copper haze

Symptoms

Slight cloudiness with a brown/red deposit at the bottom.

Appears when wine exposed to light for a long while.

Test a wine sample

Seal a bottle of a mixed solution of wine plus 30 mg/L SO₂ and stand it the light at 30 °C. 7 days later, if no haze has appeared that means the wine is stable.

Confirm copper haze

Ask a laboratory for a sodium acetate plus hydrozylamine hydrochloride test to confirm the presence of copper haze.

Prevention

Add arabic gum only if copper concentration is around 1.5 mg/L.

Treat with Bentonite, chitosane.

Heat the wine around 55-60°C to cause flocculation then rack.

Treat the wine with potassium ferrocyanide (forbidden for red wines).