I have a BonVino Suprajet filter, and the finest filter pads I can get
locally are #3, which are described as 0.5 microns - sterile filtering. In
the interests of stabilizing a white wine I would prefer didn't go through
Malo - is this pad fine enough, or where can I get one fine enough? I have
consulted with a colleague who claims to use winery grade pads in his
Suprajet to filter out the wee beasties - but I didn't ask him for his
source.

Lysozome appears not to have done the trick - or wasn't done is sufficient
volume to slay them.

regards,
steve

"steve" > wrote in message
...
> I have a BonVino Suprajet filter, and the finest filter pads I can get
> locally are #3, which are described as 0.5 microns - sterile filtering. In
> the interests of stabilizing a white wine I would prefer didn't go through
> Malo - is this pad fine enough, or where can I get one fine enough? I have
> consulted with a colleague who claims to use winery grade pads in his
> Suprajet to filter out the wee beasties - but I didn't ask him for his
> source.

You'd need a 0.45 micron _absolute_ sterile membrane to filter out ML. A
0.5 micron nominal pad won't do it. Same goes if you are trying to remove
yeast from a sweet wine.

Tom S

>You'd need a 0.45 micron _absolute_ sterile membrane to filter out ML. A
>0.5 micron nominal pad won't do it. Same goes if you are trying to remove
>yeast from a sweet wine.
>
>Tom S

>You'd need a 0.45 micron _absolute_ sterile membrane to filter out ML. A
>0.5 micron nominal pad won't do it. Same goes if you are trying to remove
>yeast from a sweet wine.
>
>Tom S
>
This whole business of filtering out bacteria just doesn't make any sense to
me. As a person who has to rely on sterile technique, I can say that there's
no half way point with sterility. Things are either sterile or they're growing
bugs, though possibly not in as high numbers. When you use a filter, there's
lots of leakage and dripping, so even if the filter was 0.45 microns, there
would still be contamination.

Add to that the fact that there has GOT to be a variation in the pore size.
Even if the average size is 0.45, then there have to be some pores that are
much larger.

I think filters do a great job in clarifying wine, but I've never had any luck
filtering out organisms.

Lee

Lee - I used to deal with sterilization (pharmaceuticals - injectables,
preparation of sterile water for mfg. of liquid products, etc.) in my work.
We relied on filtration, albeit with 0.22 micron absolute filters, plus an
integrity check after filtration. IMO filtration can be used to remove
bacteria and yeast cells. Of course most home winemakers don't have the
ability to check filter integrity. And in my basement there is great
potential for contamination downstream from the filter. Still if you are
careful in your preparation, use 0.22 micron filters, sanitize the filter
tubing and receiving vessels you can knock the numbers of organisms down
significantly if not totally. I would much rather filter a sweetened wine
before bottling than just bottle and hope for the best.

Bill Frazier
Olathe, Kansas USA

"LG1111" > wrote in message
...
> This whole business of filtering out bacteria just doesn't make any sense
to
> me. As a person who has to rely on sterile technique, I can say that
there's
> no half way point with sterility. Things are either sterile or they're
growing
> bugs, though possibly not in as high numbers. When you use a filter,
there's
> lots of leakage and dripping, so even if the filter was 0.45 microns,
there
> would still be contamination.
>
> Add to that the fact that there has GOT to be a variation in the pore
size.
> Even if the average size is 0.45, then there have to be some pores that
are
> much larger.
>
> I think filters do a great job in clarifying wine, but I've never had any
luck
> filtering out organisms.
>
> Lee

"LG1111" > wrote in message
...
> >You'd need a 0.45 micron _absolute_ sterile membrane to filter out ML. A
> >0.5 micron nominal pad won't do it. Same goes if you are trying to
remove
> >yeast from a sweet wine.
> >
> >Tom S
> >
> This whole business of filtering out bacteria just doesn't make any sense
to
> me. As a person who has to rely on sterile technique, I can say that
there's
> no half way point with sterility.

That's true - but sterile filtration is orders of magnitude better than any
alternative. IOW, it's pretty damn good.

Things are either sterile or they're growing
> bugs, though possibly not in as high numbers.

Exactly! Orders of magnitude lower.

When you use a filter, there's
> lots of leakage and dripping, so even if the filter was 0.45 microns,
there
> would still be contamination.

Are you assuming that because a filter is leaking that it has also to be
backstreaming? Probably not.

> Add to that the fact that there has GOT to be a variation in the pore
size.
> Even if the average size is 0.45, then there have to be some pores that
are
> much larger.

Nope. That's why it's called an _absolute_ filter. And let me tell you,
those suckers are _expen$ive_!

As far as determining whether the filter is capable of true sterile
filtration, it's necessary to run a bubble point check on it. IIRC, you
push water through the filter using gas (nitrogen), increasing the pressure
slowly until the gas pushes through the membrane and produces bubbles on the
other side. The pore size can be calculated from the pressure required to
do this, which is a function of pressure and surface tension of water.

> I think filters do a great job in clarifying wine, but I've never had any
luck
> filtering out organisms.

You've never used a sterile membrane cartridge filter. They do this quite
well. The one thing I don't like about them is that they have a plasticy
kind of smell that they impart to the first few gallons of wine - at least
when they are new. Run some hot water through first. That helps get rid of
it.

Tom S

I guess this question is for Lum, will the set up he has documented in
his manual have the ability to sterile filter the wine with those $25
water filters?


Bob


"Tom S" > wrote in message .com>...
> "steve" > wrote in message
> ...
> > I have a BonVino Suprajet filter, and the finest filter pads I can get
> > locally are #3, which are described as 0.5 microns - sterile filtering. In
> > the interests of stabilizing a white wine I would prefer didn't go through
> > Malo - is this pad fine enough, or where can I get one fine enough? I have
> > consulted with a colleague who claims to use winery grade pads in his
> > Suprajet to filter out the wee beasties - but I didn't ask him for his
> > source.
>
> You'd need a 0.45 micron _absolute_ sterile membrane to filter out ML. A
> 0.5 micron nominal pad won't do it. Same goes if you are trying to remove
> yeast from a sweet wine.
>
> Tom S

"bob" > wrote in message
om...
> I guess this question is for Lum, will the set up he has documented in
> his manual have the ability to sterile filter the wine with those $25
> water filters?
>
>
> Bob

Hi Bob, the answer is no. Those $25 filter housing do not provide an
adequate seal with the membrane filter cartridges.
lum

Thanks Lum,

I was thinking about getting the Super Jet Buon Vino but noticed that
their "sterile" filter pads are .5 microns . I searched this newsgroup
and found another thread pertaining to this very subject. I guess .5
microns isn't "sterile" enough to inhibit MLF so I'm not sure what
good the Super Jet is over a plain $25 plastic cartridge filter. Do
you or anyone else out there have any suggestions , advice, experience
with a fairly inexpensive way of sterilizing 100 gallons of wine?
Should I just use sorbate instead? To explain the sitiuation exactly,
I have 100 gallons of eastern chardonnay that I'm about to add
bentonite to and cold stabilize. I'm looking to make the wine
semi-dry( more towards the semi than the dry ) and want to inhibite
MLF in the bottle. I am going to add sugar to the wine because it is
dry now. Should I just "rough" filter it and address the
re-fermentation and MLF in the bottle problem with sorbate and SO2?
Any input would be greatly appreciated.

Bob

"Lum" > wrote in message >...
> "bob" > wrote in message
> om...
> > I guess this question is for Lum, will the set up he has documented in
> > his manual have the ability to sterile filter the wine with those $25
> > water filters?
> >
> >
> > Bob
>
> Hi Bob, the answer is no. Those $25 filter housing do not provide an
> adequate seal with the membrane filter cartridges.
> lum

"bob" > wrote in message
om...
> Thanks Lum,
>
> I was thinking about getting the Super Jet Buon Vino but noticed that
> their "sterile" filter pads are .5 microns . I searched this newsgroup
> and found another thread pertaining to this very subject. I guess .5
> microns isn't "sterile" enough to inhibit MLF so I'm not sure what
> good the Super Jet is over a plain $25 plastic cartridge filter. Do
> you or anyone else out there have any suggestions , advice, experience
> with a fairly inexpensive way of sterilizing 100 gallons of wine?
> Should I just use sorbate instead? To explain the sitiuation exactly,
> I have 100 gallons of eastern chardonnay that I'm about to add
> bentonite to and cold stabilize. I'm looking to make the wine
> semi-dry( more towards the semi than the dry ) and want to inhibite
> MLF in the bottle. I am going to add sugar to the wine because it is
> dry now. Should I just "rough" filter it and address the
> re-fermentation and MLF in the bottle problem with sorbate and SO2?
> Any input would be greatly appreciated.
>
> Bob

Sterile bottling involves more than just putting wine through a tight
filter. Bottles, corks, corker, etc must all be sterile.

We use the following technique to make an off-dry wine at the winery every
year:
(1) Add frozen juice (or sugar) and potassium sorbate to the wine.
(2) Adjust the molecular SO2 to 0.8 milligrams per liter.
(3) Remove as much yeast as possible with a tight pad filtration.
(4) Observe the wine for several weeks to be sure it is stable before
bottling.

Good luck
Lum,
Del Mar, California, USA