New Post on MLF Two Questions LONG was: Observations about MLF

New Post on MLF Two Questions LONG was: Observations about MLF

Post by Glen Duf » Mon, 13 Dec 2004 00:12:17



Steve and others,

I could have almost written your post exactly as you did and signed it,
knowing that is precisely my experience with whites (gewurztraminer,
riesling, pinot grigio and a variety called geisenheim).  Perhaps the
only exception to your post is that I have not made a serious attempt at
really fine filtration.  Due to the fact that I have a Buon Vino
Superjet as you do, I believe we are limited to .5 microns.  I will now
use this routinely on my whites although the medium filter seemed to
clear my wines more than adequately.  I guess the real issue is
stabilization.

Like you I tried the lysozyme route and had mixed results even when
generous doses were used.  Man does that stuff foam when added to the
must!!!  This year I plan to be a little more agressive with the SO2
maybe taking it up to 50 ppm's although reluctantly.  My philsophy has
been to minimize SO2, one of the advantages IMHO of home winemaking.

Apart from sterile filtration and the need to purchase more equipment or
the use of sorbate which I do not like, I am pretty well resigned to the
fact that we have oenococcus all over our cellar and about all I can do
is try to minimize the problem.  I rarely have ML in bottles as I bulk
age my whites for at least a year in glass before bottling and if it's
going to go through ML it usually happens by then.

I am purchasing a chromatography kit as there is some guesswork when a
wine is fermented in our cool ba***t as that can drag on for a long
time especially the last phase from 1.000 to 0.992.

Two questions:
1) When is it a good time to sulfite for bulk aging in whites you do not
want to undergo MLF and at what levels.  When I wait till the ***ic
fermentation is pretty well complete I am concerned that MLF is already
underway.  I usually start with juice that is in the 20ppm range at the
time of yeast fermentation so I am thinking by the time the SG is around
1.000 I should probably up it to around 40 or 50 ppm's.

2) I understand there is a Lalvin strain that is recommended for
aromatic wines.  I would be interested in any experience with this agent.

Any thoughts from the above two questions would be appreciated.

Glen Duff

 
 
 

New Post on MLF Two Questions LONG was: Observations about MLF

Post by LG11 » Wed, 15 Dec 2004 02:02:26


For whatever it's worth, I've had reasonably good luck with lysozyme.  Usually
I get an immediate precipitate and I know that, at the very least, "something"
is happening.  About 2 months ago I began a batch of voignier in a cool 55
degree cellar.  I treated it immediately with lysozyme.  Last night, after the
primary fermentation was completed, I racked and, just for the hell of it, I
re-treated with lysozyme (for exactly the reasons that you've stated).  But
this time, I got absolutely no precipitate, so maybe the initial treatment
actually worked.  

Lee

 
 
 

New Post on MLF Two Questions LONG was: Observations about MLF

Post by Lum » Wed, 15 Dec 2004 03:34:48



Quote:
> For whatever it's worth, I've had reasonably good luck with lysozyme.
Usually
> I get an immediate precipitate and I know that, at the very least,
"something"
> is happening.  About 2 months ago I began a batch of voignier in a cool 55
> degree cellar.  I treated it immediately with lysozyme.  Last night, after
the
> primary fermentation was completed, I racked and, just for the hell of it,
I
> re-treated with lysozyme (for exactly the reasons that you've stated).
But
> this time, I got absolutely no precipitate, so maybe the initial treatment
> actually worked.

> Lee

Lee and All,
Lysozyme is a protein and like other proteins (egg white, gelatin, etc) it
reacts with phenols and precipitates.  I suspect your first addition drooped
out what little tannin there was in the wine.  There wasn't much tannin
left, so the second addition didn't cause a significant precipitate.
Lum
Del Mar, California, USA
 
 
 

New Post on MLF Two Questions LONG was: Observations about MLF

Post by frederick ploegma » Thu, 16 Dec 2004 01:08:59


Hi Glen

Comments interspersed:


<snip>

Quote:
>This year I plan to be a little more agressive with the SO2 maybe taking it
>up to 50 ppm's although reluctantly.  My philsophy has been to minimize
>SO2, one of the advantages IMHO of home winemaking.

If you look up "living conditions" for ML Bacteria, it will tell you what
conditions they require and what conditions they are unable to tolerate.
Generally, they cannot tolerate_too_much acid, _too_much ***, or
_too_much molecular SO2.  These things are then the vulnerabilities
that can be used to control this bacteria.  Too much acid and/or ***
presents us with "balance" problems, so the usual method of controlling
MLB is through the use of an "aseptic" level of molecular SO2.

Quote:
> Apart from sterile filtration and the need to purchase more equipment or
> the use of sorbate which I do not like, ...

Sorbate inhibits yeast.  It does_not_ inhibit MLB.  In fact, MLB will
consume sorbate resulting in the "geranium" effect we so often hear
about.

<snip>

Quote:
> Two questions:
> 1) When is it a good time to sulfite for bulk aging in whites you do not
> want to undergo MLF and at what levels.

Since MLF can and does occur in_parallel_with the yeast fermentation,
you must start your SO2 regimen from the very beginning. (even before
the yeast is added)  To do this you must establish an initial "aseptic"
level in the must.  MLB has a much lower tolerance for molecular SO2
than does the commercial yeasts we use, so there is no problem with
conducting a normal ferment.

Quote:
>When I wait till the ***ic fermentation is pretty well complete I am
>concerned that MLF is already underway.

It probably is.

Quote:
>I usually start with juice that is in the 20ppm range at the time of yeast
>fermentation so I am thinking by the time the SG is around 1.000 I should
>probably up it to around 40 or 50 ppm's.

The "aseptic" (molecular) level of SO2 is effected by the pH of the wine.
So working blindly with only "free SO2" numbers just doesn't hack it.
You will need to achieve a_minimum_level of 0.8 ppm_molecular_SO2
if you hope to control this bug.

In addition.  You will find that_most_ of the initial addition of sulfite
gets
either bonded or is blown off during the ferment.  Thus it requires a
further addition of sulfite at first post ferment exposure to get the level
back up to "aseptic".  So long as this "aseptic" level is thereafter
maintained in the wine (up to and including the bottling step), there is
no risk that MLF will occur in that wine.  HTH

<snip>

        Frederick

 
 
 

New Post on MLF Two Questions LONG was: Observations about MLF

Post by benrot.. » Thu, 16 Dec 2004 08:30:01


Glen,

You should sulphite as soon as the fermentation ends (which would be <
SG 1.000). Sulphiting during fermentation is pointless (and potentially
harmful) since all the SO2 added will simply bind to acetaldehyde. I
recommend you also give the must a decent dose of SO2. Of course, there
will be a small window of opportunity for MLB during fermentation (when
SO2 levels are very low due to binding & "blow-off") and you can try
and control them with a low temperature (wouldn't you be doing a cool
ferment with Gewurz and Riesling anyway?).

HTH,
Ben

Improved Winemaking
http://members.tripod.com/~BRotter/MLF.htm

 
 
 

New Post on MLF Two Questions LONG was: Observations about MLF

Post by Glen Duf » Fri, 17 Dec 2004 06:24:27


Thanks Frederick & Ben for your helpful comments.

Ben, You're right the temperature of my fermentation is quite cool and
my Gewurz, Riesling and Pinot Grigio are nearly finished fermenting, now
down in the 1.000 range.  I just added SO2 to bring the level up to 0.8
ppm molecular as based on the pH of each, ranging from 3.33 down to 3.22.

Thanks again to both of you.

Glen Duff
----------------------------

Quote:

> Glen,

> You should sulphite as soon as the fermentation ends (which would be <
> SG 1.000). Sulphiting during fermentation is pointless (and potentially
> harmful) since all the SO2 added will simply bind to acetaldehyde. I
> recommend you also give the must a decent dose of SO2. Of course, there
> will be a small window of opportunity for MLB during fermentation (when
> SO2 levels are very low due to binding & "blow-off") and you can try
> and control them with a low temperature (wouldn't you be doing a cool
> ferment with Gewurz and Riesling anyway?).

> HTH,
> Ben

> Improved Winemaking
> http://members.tripod.com/~BRotter/MLF.htm

 
 
 

New Post on MLF Two Questions LONG was: Observations about MLF

Post by pp » Sat, 18 Dec 2004 07:02:59


Wouldn't it be better to wait with the SO2 addition until the wine is
really finished fermenting (assuming the intention is to ferment to
dryness)? I thought that the binding with aldehydes would happen even
when the wine is under 1.000 as long as it's still actively fermenting
(which most wines are).

Pp

 
 
 

New Post on MLF Two Questions LONG was: Observations about MLF

Post by pp » Sat, 18 Dec 2004 07:06:01


Wouldn't it be better to wait with the SO2 addition until the wine is
really finished fermenting (assuming the intention is to ferment to
dryness)? I thought that the binding with aldehydes would happen even
when the wine is under 1.000 as long as it's still actively fermenting
(which most wines are).

Pp