Why is there sediment in my wine?
Sediment is a naturally occurring by-product of the ageing process of red wines. As a wine ages the pigments tend to drop out of suspension. This is often added by the tannins that bond together, forming long chains that become too heavy to remain in suspension within the liquid.
Sediment is totally natural and harmless, though it can impart a muddy, bitter flavor to your wines. So, it’s best to stand the bottle up a few days before drinking and then decant the wine off the sediment into a clean decanter or just another clean bottle.