Chardonnay Acidity Questions
 

Hello all -

I made a barrel of Chardonnay this year from fresh fruit, and I
thought I'd appeal to the group to help me understand and solve a
couple of issues that have arisen.

I started with a ½ ton of BC Okanagan Chardonnay grapes, night picked,
when sugar content had reached 23 Brix and my farmer thought the
grapes had sufficient maturity. After crushing the following morning,
I measured 7.10g/L TA with pH 3.37.

I cold fermented at about 55 degrees F, warmed and ran ML (ah, and the
enjoyable butter it did produce!), and upon completion added S02 and
cold stabilised in my garage (near freezing) till the end of
December. However, when tasting the wine for the first time since
chilled, I found it flat with a degassed pH of 3.80. Yikes!

I added 0.90 g/l tartaric acid (after trials) and schlepped my tanks
back into the pseudo-cold of a BC coastal winter. Before bentonite
fining at the end of March, I noted that more tartrate salts had
precipitated in the tanks, it still tasted slightly flat, pH was 3.58,
and TA was skulking around 5.70g/L. I popped in another 0.30 g/L
tartaric and let it sit in my cellar (55 degrees) until last week.

My current sample weighs in at pH 3.55 and may yet be a bit flat. I
was worried about more precipitation from my earlier 0.30 addition, so
I chilled a sample in the fridge for the last week - nary a single
crystal, though.

I wonder:

1. Why won't this wine precipitate any further tartrate when I added
0.30g/L after cold stabilisation? Is it stable?

2. If I add another 0.20 g/L, filter with 50micron nominal pads, and
then bottle, am I going to be seeing white crystals in my future?

3. How can I mitigate this problem next year? I've been considering
front-loading tartaric acid before ferment (even though my must will
likely originate around pH3.37 with TA 7.1) or even halting ML
midstream by means of early S02 addition.

I'm trying to get my ducks straight this year, but I'm also leading a
club next year, so any advice would most appreciatively be
appreciated.

Best Regards & In Vino Veritas
Darin

Chardonnay Acidity Questions
 

One thought I have is that those cool-ripening grapes may have had
mostly malic acid and very little tartaric acid. I've seen that before
in grapes from cool climates.
When you do ML fermentation on such grapes, once the malic is converted
to lactic acid, there is little to no total acidity left.
Next year you may want to measure the malic acid content as well as the
total acidity to assess if this is what really happened to you.
If it is, you probably will want to add tartaric acid to the must.

Hope this helps.
Gene

Darin wrote:
> Hello all -
>
> I made a barrel of Chardonnay this year from fresh fruit, and I
> thought I'd appeal to the group to help me understand and solve a
> couple of issues that have arisen.
>
> I started with a ½ ton of BC Okanagan Chardonnay grapes, night picked,
> when sugar content had reached 23 Brix and my farmer thought the
> grapes had sufficient maturity. After crushing the following morning,
> I measured 7.10g/L TA with pH 3.37.
>
> I cold fermented at about 55 degrees F, warmed and ran ML (ah, and the
> enjoyable butter it did produce!), and upon completion added S02 and
> cold stabilised in my garage (near freezing) till the end of
> December. However, when tasting the wine for the first time since
> chilled, I found it flat with a degassed pH of 3.80. Yikes!
>
> I added 0.90 g/l tartaric acid (after trials) and schlepped my tanks
> back into the pseudo-cold of a BC coastal winter. Before bentonite
> fining at the end of March, I noted that more tartrate salts had
> precipitated in the tanks, it still tasted slightly flat, pH was 3.58,
> and TA was skulking around 5.70g/L. I popped in another 0.30 g/L
> tartaric and let it sit in my cellar (55 degrees) until last week.
>
> My current sample weighs in at pH 3.55 and may yet be a bit flat. I
> was worried about more precipitation from my earlier 0.30 addition, so
> I chilled a sample in the fridge for the last week - nary a single
> crystal, though.
>
> I wonder:
>
> 1. Why won't this wine precipitate any further tartrate when I added
> 0.30g/L after cold stabilisation? Is it stable?
>
> 2. If I add another 0.20 g/L, filter with 50micron nominal pads, and
> then bottle, am I going to be seeing white crystals in my future?
>
> 3. How can I mitigate this problem next year? I've been considering
> front-loading tartaric acid before ferment (even though my must will
> likely originate around pH3.37 with TA 7.1) or even halting ML
> midstream by means of early S02 addition.
>
> I'm trying to get my ducks straight this year, but I'm also leading a
> club next year, so any advice would most appreciatively be
> appreciated.
>
> Best Regards & In Vino Veritas
> Darin
>

Chardonnay Acidity Questions
 

On Jun 27, 8:22 pm, Darin > wrote:

>
> I wonder:
>
> 1. Why won't this wine precipitate any further tartrate when I added
> 0.30g/L after cold stabilisation? Is it stable?
>

Hard to say as the wine was never brought back to cold temperatures
again. You should weigh pros and cons of having possibly some small
amount of crystals in the wine in the end vs. overworking the wine
with repeated cold stabilizations.

> 2. If I add another 0.20 g/L, filter with 50micron nominal pads, and
> then bottle, am I going to be seeing white crystals in my future?

If the wine is unstable then yes, filtering won't help because there
are no crystals at this point.

>
> 3. How can I mitigate this problem next year? I've been considering
> front-loading tartaric acid before ferment (even though my must will
> likely originate around pH3.37 with TA 7.1) or even halting ML
> midstream by means of early S02 addition.

You can do either, the 1st option is easier and if you'll work with
the same grower, you have the advantage of knowing better what to
expect from the wine. In your case it sounds like you could add about
2g/L tartaric before fermentation without issues.

Pp

>
> I'm trying to get my ducks straight this year, but I'm also leading a
> club next year, so any advice would most appreciatively be
> appreciated.
>
> Best Regards & In Vino Veritas
> Darin

Chardonnay Acidity Questions
 

"Darin" > wrote in message
oups.com...
Hello all -

I made a barrel of Chardonnay this year from fresh fruit, and I
thought I'd appeal to the group to help me understand and solve a
couple of issues that have arisen.

I started with a ½ ton of BC Okanagan Chardonnay grapes, night picked,
when sugar content had reached 23 Brix and my farmer thought the
grapes had sufficient maturity. After crushing the following morning,
I measured 7.10g/L TA with pH 3.37.

I cold fermented at about 55 degrees F, warmed and ran ML (ah, and the
enjoyable butter it did produce!), and upon completion added S02 and
cold stabilised in my garage (near freezing) till the end of
December. However, when tasting the wine for the first time since
chilled, I found it flat with a degassed pH of 3.80. Yikes!

I added 0.90 g/l tartaric acid (after trials) and schlepped my tanks
back into the pseudo-cold of a BC coastal winter. Before bentonite
fining at the end of March, I noted that more tartrate salts had
precipitated in the tanks, it still tasted slightly flat, pH was 3.58,
and TA was skulking around 5.70g/L. I popped in another 0.30 g/L
tartaric and let it sit in my cellar (55 degrees) until last week.

My current sample weighs in at pH 3.55 and may yet be a bit flat. I
was worried about more precipitation from my earlier 0.30 addition, so
I chilled a sample in the fridge for the last week - nary a single
crystal, though.

I wonder:

1. Why won't this wine precipitate any further tartrate when I added
0.30g/L after cold stabilisation? Is it stable?

2. If I add another 0.20 g/L, filter with 50micron nominal pads, and
then bottle, am I going to be seeing white crystals in my future?

3. How can I mitigate this problem next year? I've been considering
front-loading tartaric acid before ferment (even though my must will
likely originate around pH3.37 with TA 7.1) or even halting ML
midstream by means of early S02 addition.

I'm trying to get my ducks straight this year, but I'm also leading a
club next year, so any advice would most appreciatively be
appreciated.

Best Regards & In Vino Veritas
Darin


Darin,
Potassium bitartrate precipitation slows down when most of the excess
potassium is gone.
I would add 0.5 g/l of citric acid to a sample of your current batch of
Chardonnay and taste it. Citric acid wont precipitate, so it wont change
the stability and the slight "citric" taste often enhances white wines.
Lum

Chardonnay Acidity Questions
 

On Jun 28, 5:59 pm, "Lum" > wrote:
> "Darin" > wrote in message
>
> oups.com...
> Hello all -
>
> I made a barrel of Chardonnay this year from fresh fruit, and I
> thought I'd appeal to the group to help me understand and solve a
> couple of issues that have arisen.
>
> I started with a ½ ton of BC Okanagan Chardonnay grapes, night picked,
> when sugar content had reached 23 Brix and my farmer thought the
> grapes had sufficient maturity. After crushing the following morning,
> I measured 7.10g/L TA with pH 3.37.
>
> I cold fermented at about 55 degrees F, warmed and ran ML (ah, and the
> enjoyable butter it did produce!), and upon completion added S02 and
> cold stabilised in my garage (near freezing) till the end of
> December. However, when tasting the wine for the first time since
> chilled, I found it flat with a degassed pH of 3.80. Yikes!
>
> I added 0.90 g/l tartaric acid (after trials) and schlepped my tanks
> back into the pseudo-cold of a BC coastal winter. Before bentonite
> fining at the end of March, I noted that more tartrate salts had
> precipitated in the tanks, it still tasted slightly flat, pH was 3.58,
> and TA was skulking around 5.70g/L. I popped in another 0.30 g/L
> tartaric and let it sit in my cellar (55 degrees) until last week.
>
> My current sample weighs in at pH 3.55 and may yet be a bit flat. I
> was worried about more precipitation from my earlier 0.30 addition, so
> I chilled a sample in the fridge for the last week - nary a single
> crystal, though.
>
> I wonder:
>
> 1. Why won't this wine precipitate any further tartrate when I added
> 0.30g/L after cold stabilisation? Is it stable?
>
> 2. If I add another 0.20 g/L, filter with 50micron nominal pads, and
> then bottle, am I going to be seeing white crystals in my future?
>
> 3. How can I mitigate this problem next year? I've been considering
> front-loading tartaric acid before ferment (even though my must will
> likely originate around pH3.37 with TA 7.1) or even halting ML
> midstream by means of early S02 addition.
>
> I'm trying to get my ducks straight this year, but I'm also leading a
> club next year, so any advice would most appreciatively be
> appreciated.
>
> Best Regards & In Vino Veritas
> Darin
>
> Darin,
> Potassium bitartrate precipitation slows down when most of the excess
> potassium is gone.
> I would add 0.5 g/l of citric acid to a sample of your current batch of
> Chardonnay and taste it. Citric acid wont precipitate, so it wont change
> the stability and the slight "citric" taste often enhances white wines.
> Lum

Exactly what I was thinking, just follow Lum's advice to add it to a
sample first and not the whole batch. I think you are getting close
to having it where you will want it. Citric acid is usually a good
choice for touching up wine acidity. You don't have a pH problem so
that helps since citric won't swing pH as much as tartaric. Go by
taste now and then measure. You don't want to get too caught up on
the numbers; you are are making food not building a deck. :)

That is one of the problems with ML fermentation, you want that butter
so you need to do it. If you wanted it a little less complex but
tarter foregoing the ML might have been an option to consider. Your
grapes sounded pretty good so I would have done exactly what you did.

Joe

Chardonnay Acidity Questions
 

Darin wrote:
> Hello all -
>
> I made a barrel of Chardonnay this year from fresh fruit, and I
> thought I'd appeal to the group to help me understand and solve a
> couple of issues that have arisen.
>
> I started with a ½ ton of BC Okanagan Chardonnay grapes, night picked,
> when sugar content had reached 23 Brix and my farmer thought the
> grapes had sufficient maturity. After crushing the following morning,
> I measured 7.10g/L TA with pH 3.37.
>
> I cold fermented at about 55 degrees F, warmed and ran ML (ah, and the
> enjoyable butter it did produce!), and upon completion added S02 and
> cold stabilised in my garage (near freezing) till the end of
> December. However, when tasting the wine for the first time since
> chilled, I found it flat with a degassed pH of 3.80. Yikes!

A quick rule of thumb for pH adjustment. Say you want to shoot for pH
3.5. To calculate the amount of acid to subtract the desired pH, from
the starting pH, and the divide by 0.15. Hence (3.8-3.5)/0.15 = 0.3/0.15
= 2 g/L. This is how much I would have added then. Generally about half
of the acid would have dropped out straight away, and a bit more down
the track, but in your case this would not have happened.

Check the pH TA after malolactic. If the pH is greater than 3.65, then
cold stabilising will raise the pH. If it is less than 3.65 then the pH
will drop during cold stabilising. Hence upon completion of malo check
pH, TA, and adust pH down to say 3.5 or 3.4 if you have room without
blowing you TA too high. Remember that SO2 works much better at a pH 3.4
or 3.3 than at 3.6, and hence the wine will last much longer. Earlier
you add the acid, the less affect it has on the final TA. Be brave early
on and you will have a wine which lasts well.


James.




>
> I added 0.90 g/l tartaric acid (after trials) and schlepped my tanks
> back into the pseudo-cold of a BC coastal winter. Before bentonite
> fining at the end of March, I noted that more tartrate salts had
> precipitated in the tanks, it still tasted slightly flat, pH was 3.58,
> and TA was skulking around 5.70g/L. I popped in another 0.30 g/L
> tartaric and let it sit in my cellar (55 degrees) until last week.
>
> My current sample weighs in at pH 3.55 and may yet be a bit flat. I
> was worried about more precipitation from my earlier 0.30 addition, so
> I chilled a sample in the fridge for the last week - nary a single
> crystal, though.
>
> I wonder:
>
> 1. Why won't this wine precipitate any further tartrate when I added
> 0.30g/L after cold stabilisation? Is it stable?
>
> 2. If I add another 0.20 g/L, filter with 50micron nominal pads, and
> then bottle, am I going to be seeing white crystals in my future?
>
> 3. How can I mitigate this problem next year? I've been considering
> front-loading tartaric acid before ferment (even though my must will
> likely originate around pH3.37 with TA 7.1) or even halting ML
> midstream by means of early S02 addition.
>
> I'm trying to get my ducks straight this year, but I'm also leading a
> club next year, so any advice would most appreciatively be
> appreciated.
>
> Best Regards & In Vino Veritas
> Darin
>

Chardonnay Acidity Questions
 

Gentlemen - sage advice from all and I really appreciate your
comments.

I hadn't considered citric acid before because of a perception that it
is readily noticeable in a non-fruit-forward wine like Chardonnay.
That said, I'm going to assemble a panel of critics - otherwise known
as friends, family, and neighbours - and run them through a series of
citric addition trials. We'll see how it goes.

I like the idea of determining malate before ferment and correcting
the must accordingly. I haven't researched this yet, but wonder
what's involved in the testing. I currently do free S02 by vacuum
aspiration, TA by titration, and pH by meter. First year chemistry
was a few years (decades..) ago, but I'm remembering more with every
vintage.

Interesting comment on the direction of pH swing during cold
stabilisation. Why would the pH go down if hydrogen ions were being
used up to form potassium bi-tartrate? I thought the process always
drove the number up.

Thanks again and best regards,
Darin