0,45 micron is sterile as long as the media is "absolute". and not
"nominal" rating. There is no need to recircule the wine back to the
initial container, filtering twice the wine with the same media is a
waste of time and could affect the quality of the wine + you could need
higher level of free So2 to compensate for this second filtering. The
problem with sterile filtering is that even if you sterile filter the
wine your bottles, bottling device, corking device and environement are
not sterile. So, a small quantity of yeast cell could still end up in
your bottled wines and cause later problems. That's why I said that
sorbate is the best method for at least for amateurs winemakers. I can
understand large winery being equiped differently ( sterile equipment
and environement ) to do it properly but you are certainly not. This
is a risk that I would not take. With my Icewine production, I use
sorbate at 0,182gr/L ratio and I keep the free So2 in line with my pH
at a molecular level of 1ppm and I fine filter at 0,5 micron. I never
had a problem doing it this way since more than 10 years.

Séb

wrote:
> I realize I talk about sterile filtering alot here.... please forgive
> me-
>
> If I were to sterile filter my wine with full recycle (sterile filter
> and recirc back to the initial container to assist in removing
> impurities/building up cake) then what should I be afraid of?
>
> What methods of failure are lurking that I'm not aware of?
>
> And should I move to 0.2 micron filtration or is 0.4 micron filtration
> sufficient for that high-sugar wine?
>
> Jason
> Joe Sallustio wrote:
> > I would agree with everything Doug mentioned. I make some very fruity
> > higher acid wines from North Eastern fruit such as Catawba, Cayuga etc
> > along with other hybrids. If you don't sweeten them they are just too
> > unbalanced as to acid to be pleasant. They are just better with some
> > sweetness. Those are good anytime. Desert wines are often used at the
> > end of the meal although anyone who tells you there are hard and fast
> > rules about wines and pairings just does not realize the breadth of the
> > subject.
> >
> > Personal preferences often change with time. I do remember liking
> > Lambrusco when I was much younger. I'm not sure anyone will ever
> > convince me I need to make it for myself now though. There is a
> > natural progression with wines where new wine drinkers prefer sweet to
> > begin with then progress to simple whites, then more complex dry whites
> > and then the same gamut with reds, from lighter to more full bodied.
> >
> > I would say dessert wines don't actually fit into that progression;
> > most people like at least one type or another and always do. I like
> > cream sherry but not port. Go figure.
> >
> > Some dessert wines have had alcohol added to them to prevent
> > fermentation, a high proof alcohol is used to stop the fermentation.
> > They are very stable at that point. The idea is to get the alcohol
> > above the point the yeast tolerate.
> >
> > Joe