In a previous post I mentioned that I had incorrectly measured TA
because I used .1N NaOH in a TA test where I should have used .2
This lead me to the erroneous conclusion that I had the dreaded high
acid, high pH fruit. I proceeded down the path of fermentation followed
by MLF figuring I had to reduce the acidity even though it would raise
the pH.

Thanks to some help from Greg Boyd and Ben Rotter I was able to
backtrack and recalculate the original juice details where TA was half
of what I incorrectly measured:

1. So it turns out the original numbers from the juice we
Cabernet TA 0.475 pH 3.89 (TA mis-measured 9.5)
Zinfandel TA 0.55 pH 3.98 (TA mis-measured 11)
Merlot TA 0.6 pH 3.9 (TA mis-measured 12)
Chardonnay TA 0.675 pH 3.53 (TA mis-measured 13.5)

2. I discovered the error before adding MLF (to the reds) toward the
middle of primary fermentation and measured using the correct .2N NaOH:
Cabernet TA 0.76 pH 3.87
Zinfandel TA 0.9 pH 3.84
Merlot TA 0.84 pH 3.67
Chardonnay TA 0.88 pH 3.43

OK, still looks like high acid and pH though I can't quite relate these
numbers to the back calculated numbers in #1. Something just doesn't
seem right. At any rate given these numbers I thought I would put the
reds through MLF.

3. 5 Days of MLF lead to the following numbers:
Cabernet TA 0.5 pH 3.97
Zinfandel TA 0.65 pH 3.86
Merlot TA 0.64 pH 3.72

At this point I added 50ppm sulfite and moved them into a 58 deg cellar.

So now I am faced with a number of questions.
A. Not sure about the numbers in 1 and 2. Doesn't give me a lot of
confidence.
B. Seems that MLF went real fast. I did verify with paper
chromotography. Is 5 days common?
C. Do I add tartaric acid to these now post fermentation and MLF to
lower pH and increase acid? If so how much change should I try to
achieve?

By the way, these are the quantities I am working with:
Cabernet 18 liters
Zinfandel 36 liters
Merlot 19 liters

thanks for any help,
Dan

Dan - Did you degas your samples before measuring TA and pH. Wine samples
taken during fermentation will be full of CO2 and this will give you false
results unless you heat the sample to boil off the CO2 and then replace the
lost volume with distilled water.

Bill Frazier
Olathe, Kansas USA

"Daniel Tortorici" > wrote in message >
> 2. I discovered the error before adding MLF (to the reds) toward the
> middle of primary fermentation and measured using the correct .2N NaOH:
> Cabernet TA 0.76 pH 3.87
> Zinfandel TA 0.9 pH 3.84
> Merlot TA 0.84 pH 3.67
> Chardonnay TA 0.88 pH 3.43
>
> OK, still looks like high acid and pH though I can't quite relate these
> numbers to the back calculated numbers in #1. Something just doesn't
> seem right. At any rate given these numbers I thought I would put the
> reds through MLF.
>
> 3. 5 Days of MLF lead to the following numbers:
> Cabernet TA 0.5 pH 3.97
> Zinfandel TA 0.65 pH 3.86
> Merlot TA 0.64 pH 3.72
>

Dan,
I would agree with Bill, degas and remeasure.

Measure out either 50 or 100 ml of must or wine.

Heat in microwave until boiling.

Cool back to room temperature.

Add distillled water back to 50 or 100 ml.

Calibrate the pH meter.

Measure both TA and pH.

I use 10 ml for the sample and use 0.1 normal NaOH. You can check the
NaOH with Potassium Acid Phalate to get the actual normality and use
Bens formula, that is what I do.

Hope that helps.

Joe


"William Frazier" > wrote in message >...
> Dan - Did you degas your samples before measuring TA and pH. Wine samples
> taken during fermentation will be full of CO2 and this will give you false
> results unless you heat the sample to boil off the CO2 and then replace the
> lost volume with distilled water.
>
> Bill Frazier
> Olathe, Kansas USA
>
> "Daniel Tortorici" > wrote in message >
> > 2. I discovered the error before adding MLF (to the reds) toward the
> > middle of primary fermentation and measured using the correct .2N NaOH:
> > Cabernet TA 0.76 pH 3.87
> > Zinfandel TA 0.9 pH 3.84
> > Merlot TA 0.84 pH 3.67
> > Chardonnay TA 0.88 pH 3.43
> >
> > OK, still looks like high acid and pH though I can't quite relate these
> > numbers to the back calculated numbers in #1. Something just doesn't
> > seem right. At any rate given these numbers I thought I would put the
> > reds through MLF.
> >
> > 3. 5 Days of MLF lead to the following numbers:
> > Cabernet TA 0.5 pH 3.97
> > Zinfandel TA 0.65 pH 3.86
> > Merlot TA 0.64 pH 3.72
> >

No, I didn't de-gas before measuring during fermentation. Which way does
the CO2 effect readings for pH and TA - higher, lower?

The question still remains - what do I do now? Can I raise acid with
tartaric post fermentation and MLF without bad consequences?

thx
dan


In article > ,
says...
> Dan,
> I would agree with Bill, degas and remeasure.
>
> Measure out either 50 or 100 ml of must or wine.
>
> Heat in microwave until boiling.
>
> Cool back to room temperature.
>
> Add distillled water back to 50 or 100 ml.
>
> Calibrate the pH meter.
>
> Measure both TA and pH.
>
> I use 10 ml for the sample and use 0.1 normal NaOH. You can check the
> NaOH with Potassium Acid Phalate to get the actual normality and use
> Bens formula, that is what I do.
>
> Hope that helps.
>
> Joe
>

Daniel Tortorici wrote "No, I didn't de-gas before measuring during
fermentation. Which way does
the CO2 effect readings for pH and TA - higher, lower? The question still
remains - what do I do now? Can I raise acid with tartaric post
fermentation and MLF without bad consequences?"

Dan - I think the question is...how confident are you in the post ML
numbers. Your acid numbers seem pretty good. The pH is high.

5 Days of MLF lead to the following numbers:
Cabernet TA 0.5 pH 3.97
Zinfandel TA 0.65 pH 3.86
Merlot TA 0.64 pH 3.72

I bet there's still some CO2 in solution that's affecting your pH and TA
measurements. Before I would consider adding anything to the wines I would
degas, retest and evaluate the wine flavor. In the end the real question
is; how does the wine taste.

Bill Frazier
Olathe, Kansas USA

Bill,
Thanks for the suggestions. When I get back home this weekend I'll degas
and retest as you suggested. As for taste the Cab is a little flat
otherwise the others seem fine.
dan



In article >,
says...
> Daniel Tortorici wrote "No, I didn't de-gas before measuring during
> fermentation. Which way does
> the CO2 effect readings for pH and TA - higher, lower? The question still
> remains - what do I do now? Can I raise acid with tartaric post
> fermentation and MLF without bad consequences?"
>
> Dan - I think the question is...how confident are you in the post ML
> numbers. Your acid numbers seem pretty good. The pH is high.
>
> 5 Days of MLF lead to the following numbers:
> Cabernet TA 0.5 pH 3.97
> Zinfandel TA 0.65 pH 3.86
> Merlot TA 0.64 pH 3.72
>
> I bet there's still some CO2 in solution that's affecting your pH and TA
> measurements. Before I would consider adding anything to the wines I would
> degas, retest and evaluate the wine flavor. In the end the real question
> is; how does the wine taste.
>
> Bill Frazier
> Olathe, Kansas USA
>
>
>

Daniel Tortorici wrote "No, I didn't de-gas before measuring during
fermentation. Which way does
the CO2 effect readings for pH and TA - higher, lower? The question still
remains - what do I do now? Can I raise acid with tartaric post
fermentation and MLF without bad consequences?"

Dan - I think the question is...how confident are you in the post ML
numbers. Your acid numbers seem pretty good. The pH is high.

5 Days of MLF lead to the following numbers:
Cabernet TA 0.5 pH 3.97
Zinfandel TA 0.65 pH 3.86
Merlot TA 0.64 pH 3.72

I bet there's still some CO2 in solution that's affecting your pH and TA
measurements. Before I would consider adding anything to the wines I would
degas, retest and evaluate the wine flavor. In the end the real question
is; how does the wine taste.

Bill Frazier
Olathe, Kansas USA

Two things:

First, distilled water (at least if you buy it off the store shelf)
usually is not pH 7. It reacts with CO2 in the air and becomes
somewhere between 5.6 and 7.0 from what I've read. Tested some from a
freshly opened jug here at work once and it was a ways from neutral -
don't remember the measurements now.

I guess it could be easily adjusted to 7, but would this affect the Ta
reading?

Second, shouldn't your pH have went up after boiling, Bill?

Miker wrote >
> First, distilled water (at least if you buy it off the store shelf)
> usually is not pH 7. It reacts with CO2 in the air and becomes
> somewhere between 5.6 and 7.0 from what I've read. Tested some from a
> freshly opened jug here at work once and it was a ways from neutral -
> don't remember the measurements now.
>
> I guess it could be easily adjusted to 7, but would this affect the Ta
> reading?
>
> Second, shouldn't your pH have went up after boiling, Bill?
Yes Miker, it seems like the pH should have gone up. Maybe stay the same
but not go down. Back when I worked in a pharmaceutical lab you would stick
a pH probe in distilled water. The pH reading would wander around and never
settle. That was very good quality distilled water and the pH readings were
what I would expect. I don't expect the same result from grocery store
distilled water but it should be better than what I would experience with
Johnson County, Kansas tap water. The pH of our local water is near 9
because of addition of chlorine, chloramine and slaked lime.

I'll give a try to grocery store reverse osmosis water and report back.

Bill Frazier
Olathe, Kansas USA

Miker wrote >
> First, distilled water (at least if you buy it off the store shelf)
> usually is not pH 7. It reacts with CO2 in the air and becomes
> somewhere between 5.6 and 7.0 from what I've read. Tested some from a
> freshly opened jug here at work once and it was a ways from neutral -
> don't remember the measurements now.
>
> I guess it could be easily adjusted to 7, but would this affect the Ta
> reading?
>
> Second, shouldn't your pH have went up after boiling, Bill?
Yes Miker, it seems like the pH should have gone up. Maybe stay the same
but not go down. Back when I worked in a pharmaceutical lab you would stick
a pH probe in distilled water. The pH reading would wander around and never
settle. That was very good quality distilled water and the pH readings were
what I would expect. I don't expect the same result from grocery store
distilled water but it should be better than what I would experience with
Johnson County, Kansas tap water. The pH of our local water is near 9
because of addition of chlorine, chloramine and slaked lime.

I'll give a try to grocery store reverse osmosis water and report back.

Bill Frazier
Olathe, Kansas USA

Dan - Did you degas your samples before measuring TA and pH. Wine samples
taken during fermentation will be full of CO2 and this will give you false
results unless you heat the sample to boil off the CO2 and then replace the
lost volume with distilled water.

Bill Frazier
Olathe, Kansas USA

"Daniel Tortorici" > wrote in message >
> 2. I discovered the error before adding MLF (to the reds) toward the
> middle of primary fermentation and measured using the correct .2N NaOH:
> Cabernet TA 0.76 pH 3.87
> Zinfandel TA 0.9 pH 3.84
> Merlot TA 0.84 pH 3.67
> Chardonnay TA 0.88 pH 3.43
>
> OK, still looks like high acid and pH though I can't quite relate these
> numbers to the back calculated numbers in #1. Something just doesn't
> seem right. At any rate given these numbers I thought I would put the
> reds through MLF.
>
> 3. 5 Days of MLF lead to the following numbers:
> Cabernet TA 0.5 pH 3.97
> Zinfandel TA 0.65 pH 3.86
> Merlot TA 0.64 pH 3.72
>

Dan - Did you degas your samples before measuring TA and pH. Wine samples
taken during fermentation will be full of CO2 and this will give you false
results unless you heat the sample to boil off the CO2 and then replace the
lost volume with distilled water.

Bill Frazier
Olathe, Kansas USA

"Daniel Tortorici" > wrote in message >
> 2. I discovered the error before adding MLF (to the reds) toward the
> middle of primary fermentation and measured using the correct .2N NaOH:
> Cabernet TA 0.76 pH 3.87
> Zinfandel TA 0.9 pH 3.84
> Merlot TA 0.84 pH 3.67
> Chardonnay TA 0.88 pH 3.43
>
> OK, still looks like high acid and pH though I can't quite relate these
> numbers to the back calculated numbers in #1. Something just doesn't
> seem right. At any rate given these numbers I thought I would put the
> reds through MLF.
>
> 3. 5 Days of MLF lead to the following numbers:
> Cabernet TA 0.5 pH 3.97
> Zinfandel TA 0.65 pH 3.86
> Merlot TA 0.64 pH 3.72
>

Two things:

First, distilled water (at least if you buy it off the store shelf)
usually is not pH 7. It reacts with CO2 in the air and becomes
somewhere between 5.6 and 7.0 from what I've read. Tested some from a
freshly opened jug here at work once and it was a ways from neutral -
don't remember the measurements now.

I guess it could be easily adjusted to 7, but would this affect the Ta
reading?

Second, shouldn't your pH have went up after boiling, Bill?

Two things:

First, distilled water (at least if you buy it off the store shelf)
usually is not pH 7. It reacts with CO2 in the air and becomes
somewhere between 5.6 and 7.0 from what I've read. Tested some from a
freshly opened jug here at work once and it was a ways from neutral -
don't remember the measurements now.

I guess it could be easily adjusted to 7, but would this affect the Ta
reading?

Second, shouldn't your pH have went up after boiling, Bill?