Why Filter Wine?
I am amazed at the number of people who filter their wines almost as a matter of course, without even waiting to see whether they have a clearing problem or not. So let me say filtering should not be necessary and will not improve the flavour of any wine. Nor will it remove cloudiness caused by the presence of pectin or starch.
The main drawback with filtering is that it very often causes over-oxidation. This is caused by long exposure to oxygen in the air, which the wine absorbs. A fully robust wine may lose much of its flavour after filtering. However, delicate wines or those with, let’s call them, ‘tender’ flavours, are likely to become quite flat and lifeless after filtering. They end up with none of the characteristics normally found in a wine. Beer is affected similarly. That occasional flat pint served over the bar is more often than not caused by oxidation.
There are modern means of avoiding this sort of thing, mainly by using various types of filters which have recently become available to home wine-makers. But this means a lot of expense for what is usually a very small quantity of wine, and I am the last person to advise unnecessary expense. For better to avoid the causes that make filtering necessary. I appreciate that most commercial wines are filtered, but commercial producers treating perhaps a thousand gallons at a time use high speed apparatus which precludes the possibility of oxidation.