mannoproteins are polysaccharides released from yeast cells during fermentation and by autolysis during lees ageing. Their release is generally considered beneficial and is encouraged by slightly higher fermentation temperatures and the length of time the wine is in contact with the yeast lees. Mannoproteins have the potential to protect white and rosé wine from protein haze and can inhibit tartrate crystal formation. They may also reduce the perception of astringency by disrupting the binding of salivary proteins with tannins. Finally, mannoproteins released during yeast autolysis have been demonstrated to improve the foaming properties of sparkling wine.
