> wrote in message
ups.com...
> John,
>
> Just curious, has anyone filtered with a .5 - 1 micron filter and have
> re-fermentation happen after bottling with R/S? According to the size
> of yeast cells , anything below 5 microns should filter them out. Do we
> have any winemakers out there with examples of re-fermentation or is
> the caution just been handed down from generation to generation without
> actual instances of this hapenning??
>
> Bob

Bob,

It depends on the type of filter used. A 0.45 micron (absolute) membrane
filter will not pass yeast or bacteria. A 0.5 (nominal) cellulose pad
filter will pass some yeast cells, and much yeast will be passed when the
filter start to blind. More info here
http://home.att.net/~lumeisenman/chapt16.html

Lum
Del Mar, California, USA