You can get sterile filtration equipment easily down to the 0.1 micron
range. I purchase 0.45 micron depth filters (nom), which (as of yet)
have not permitted any re-fermentation of any wine.

I'll let you know in 2 years whether or not the honey meads have
started back up.

The filter sheets run about 50 cents apiece, and are each easily
capapble of doing 10 gallons+.

Jason

RD wrote:
> Bob,
>
> It sounds like you're talking about the difference between 'polish
> filtration' and 'sterile filtration'. Polish filtration is often done
> with a 1 - 5 micron filter. It will not exclude yeast or many other
> microbes. If you need to remove yeast with certainty you need to
> filter through a 0.45 micron filter (or smaller).
>
> Having said this, Port is usually fortified to nearly 20% alcohol.
> That should be pretty effective at killing your yeast population.
>
> RD
>
>
> Bob Becker wrote:
> > I'm in the process of making a port wine kit.
> >
> > As part of the process they specify filtering to get rid of
> > the yeast to eliminate the possibility of further fermentation
> > of the residual sugars once the port is bottled.
> >
> > I just re-read the previous thread about filtering, but it seemed
> > geared toward clarification rather than filtering yeast.
> >
> > Is there a difference, or will any filtration system clarify
> > and also eliminate yeast?
> >
> >
> > --
> > Bob Becker
> >
> > www.becker.org