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.
For my many years of work as an editor with a wine and culinary focus, I always like to inform myself about special questions at Wine lexicon. Spontaneous reading and following links often leads to exciting discoveries in the wide world of wine.
Dr. Christa Hanten
Fachjournalistin, Lektorin und Verkosterin, Wien