Wine filtering is thought to have negative impacts on the character of each wine, resulting in less flavour in the wine. Unfiltered wines keep the particles intact at the bottom of the wine bottle, which is thought to allow the wine to age better because the natural flavours are kept to infuse into the wine creating a bolder taste over time. The sediment build up in red wines in a good indication that the wine is ageing well.
The filtering process removes components of the wines natural body, which is thought to be unnatural, however, this is at large debate. When drinking unfiltered wines, it is recommended to pour the wine slowly and carefully, so the sediment is not carried with the wine, leaving around an ounce in the bottle with the sediment. The use of a decanter can make this priceless easier and more thorough. The leftover particles are from the fermentation and are not harmless, however, may be to drink.