Ben, I just saw this thread and I make the following comments:
- assuming that the amount of Malic present is as you say, you have been
given the correct suggestions. Whether you are prepared to implement
them or not, whether they are convenient or not, it's entirely your
decision.
- what type of fruit and what quantity of wine are you making that you
feel "compelled" to use it? Unless there is a reason, other than for
discussion purposes....
- If you must use such an unripe/unsuitable fruit to make wine, then you
are obviously prepared for the result: You MAY be able to make great
wine from great fruit, but you WILL NOT make great wine from poor fruit.
That simple.
- In your case, you do the best things you can (or retain practical),
and pray for a good result:
1. add Tartaric acid to adjust pH to its minimal acceptable level (at
3.5 I would leave it alone!);
2. do a pre-fermentation biological conversion of Malic acid (there are
enzymes also available);
3. use a yeast that 'eats up' Malic during fermentation;
4. provide nutrients and perform MLF (cold stabilisation may not help if
there is no Tartaric);
6. encourage longer lees contact;
7. blend with another fruit, preferably overripe;
8. sweeten/stabilise the wine prior to bottling.
The details of performing each step have been widely discussed in other
threads.

Cheers, Giovanni.


"Ben Rotter" wrote in message
om...
Thanks everyone for your replies. I will reply by method:

**CARBONATES

Bill Frazier wrote:
Consider dividing the wine into two fractions...

Does dividing and deacidifying give a significantly different pH to
deacidifying it all in one go?

If pH is too high to begin with make that adjustment before you
begin.

Are you suggesting I acidify to correct the pH and then deacidify for
TA? Seems counterproductive to me.

**COLD STABILISING

John Dixon wrote:
How would you go about determining what percentage of your acid is
Malic?

I am working with malic fruit (e.g. gooseberries, raspberries, etc) so
it's pretty certain.

I would add the additional tataric prefermentation and
precipitate out the excess later.

As the only method that is not a practical soltuion: you can correct
the pH with the tartaric acid, but once you remove it through cold
stabilising (and that's assuming you even if you manage remove it all)
you still have all the malic you started with.

**MLF

Tom S wrote:
It depends somewhat on whether it's a red or white wine, but I'd
probably
hit it with tartaric to get the pH down to something reasonable
(3.3?),
ferment it and let the ML go. I'm not a big fan of ML inhibition.
I want
my wines to be stable without having to sterile filter or
oversulfite them.

Firstly, if you have a malic dominant must then you're basically
suggesting you replace all that malic with tartaric and conduct a full
MLF (that's the only way you'll have secure stability without sterile
filtration). That is a possibility but it would change the acid
profile quite a bit.

Secondly, I'm often dealing with wines I'd rather not put through MLF
anyway (both in terms of the hastle of it and in terms of style), so
if I can find an alternative it'd be nice.

**COMBINED STRATEGIES

I have often thought of combining strategies. For example, you could
lower the pH with tartaric, then deacidify the malic portion of the TA
with MLF, then precipitate some of the tartaric out by cold
stabilising. But (1) this is an incredibly uncertain way of going
about things with all the unknowns on the shifts to both TA and pH
you'd incur, and (2) I'd rather not have to make so many adjustments
(somehow it seems to "damage" the wine).

More interestingly:

(1) you could deacidifying by using yeast 71B-1122. But even that will
only reduce like 20-40% of your malic, and when you have musts at 10
g/l that's just not enough. Anyone have any data on the TA reduction
caused by this in malic-dominant wines BTW?

(2) you could conduct a pre-fermentation biological deacidification of
malic acid by Lactobacillus plantarum. But I've only ever seen it sell
in LARGE packs which I am not prepared to buy.

Lots of ideas and lots of problems. Any solutions?

Thanks for your input,
Ben