This wine defect is caused by oxidative processes in the wine, which is caused, among other things, by rotten and contaminated grapes. In the initial stage, the wine takes on a golden yellow colour (high colouring), which then changes to brownish. In this stage, one also speaks of a brown tinge. If the oxidation processes take a long time to react, tannins (phenols) and proteins can polymerise (cake together), which is then called brown fracture. The resulting compounds are insoluble and precipitate.
Such a wine shows a fine flaky turbidity. The white wines get a yellow-orange to brownish-yellow colour, the red wines a dull red to ochre-brown colour. The wine shows aromas of pears, bread crust and dried fruit with a stale, oily and empty nut tone. In red wine, this can lead to a complete loss of colour. If iron is also involved, the flakes take on a blue-green to blackish-green colour, which is called black break. The unpleasant wine defect is prevented or combated by sulphurisation.
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