I have finally moved from the Brew King kits to buying grapes. I picked up
100 pounds of Cabernet grapes the other day and they are happily fermenting
away (still on the skins). OG was 21.3°P and TA was between 60 and 70 I
should have used smaller increments but WTF, it was my first time measuring
TA). What is the difference between TA and pH? I have a chem degree some a
technical answer is welcome. I haven't measured pH yet as my meter needs new
batteries.

-Danno

--
email me at s_danno at msn dot com
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danno wrote:
I have finally moved from the Brew King kits to buying grapes. I picked up
100 pounds of Cabernet grapes the other day and they are happily fermenting
away (still on the skins). OG was 21.3°P and TA was between 60 and 70 I
should have used smaller increments but WTF, it was my first time measuring
TA). What is the difference between TA and pH? I have a chem degree some a
technical answer is welcome. I haven't measured pH yet as my meter needs new
batteries.

-Danno



Hi Danno

TA is a measurement of the amount of acid in your sample usually stated
as a ratio of ml/L. When you measure pH you are measuring the strength
of those acids.

Regards

Frank

On 10/22/03 5:07 PM, in article ,
"danno" wrote:

I have finally moved from the Brew King kits to buying grapes. I picked up
100 pounds of Cabernet grapes the other day and they are happily fermenting
away (still on the skins). OG was 21.3°P and TA was between 60 and 70 I
should have used smaller increments but WTF, it was my first time measuring
TA). What is the difference between TA and pH? I have a chem degree some a
technical answer is welcome. I haven't measured pH yet as my meter needs new
batteries.

-Danno

Since you have a chem degree, you know pH is a measure of the Hydronium ion
concentration in solution (H20 + HX --- H3O+ + X-). The pH is highly
subject to the buffering action of the other substituents in the wine
(potassium salts, etc). The TA number (titratable acidity) is a measure of
how many acidic protons can be neutralized with NaOH, but it refers to a
standard. Typically, the TA 0.60-0.70 referes to the percent of tartaric
acid (2 equivalents of H+) present in the wine. Some standards use H2SO4 as
the standard the TA is related to. Sometimes you will see TA represented as
percent, and sometimes as g of the specific standard acid per L.

Go to Jack Keller's site. He has a pretty good description.

Ray

"danno" wrote in message
...
I have finally moved from the Brew King kits to buying grapes. I picked up
100 pounds of Cabernet grapes the other day and they are happily
fermenting
away (still on the skins). OG was 21.3°P and TA was between 60 and 70 I
should have used smaller increments but WTF, it was my first time
measuring
TA). What is the difference between TA and pH? I have a chem degree some
a
technical answer is welcome. I haven't measured pH yet as my meter needs
new
batteries.

-Danno
.
--
email me at s_danno at msn dot com
---------------------------------------------------------

"danno" wrote:

What is the difference between TA and pH? I have a chem degree some a
technical answer is welcome. I haven't measured pH yet as my meter needs
new
batteries.

TA is the percent by weight of acid in solution, expressed in terms of
tartaric, i.e. grams tartaric / ml solution * 100, or grams tartaric per 100
ml. solution.

[From the ph faq]

pH is related to an acid's strength in wine, while the TA relates to the
amount of acid. Although interrelated, they are not the same thing. A
solution containing a specific quantity of a relatively weaker acid such as
malic acid will have a different (higher) pH than a solution containing the
same quantity of a stronger acid such as tartaric.

The pH of a solution is defined as the -log of the hydrogen ion. Given the
measurement is logarithmic in nature, a solution with a pH of 3.0 is ten
times stronger than a pH of 4.0. The total quantity of hydrogen and
hydroxyl ions is constant in a solution, as one increases the other
decreases. Acidic solutions contain more hydrogen ions than hydroxyl ions;
basic solutions contain more hydroxyl ions than hydrogen ions. A pH of 7 is
neutral (neither acid or base) as the concentration of hydrogen ions and
hydroxyl ions are equal at that point.

HTH

Great. Thanks! Jack explained the two quite well and I can now move on to my
next question for which I will create a new topic.

-Danno

--
email me at s_danno at msn dot com
---------------------------------------------------------


"Ray" wrote in message
...
Go to Jack Keller's site. He has a pretty good description.

Ray

"danno" wrote in message
...
I have finally moved from the Brew King kits to buying grapes. I picked
up
100 pounds of Cabernet grapes the other day and they are happily
fermenting
away (still on the skins). OG was 21.3°P and TA was between 60 and 70 I
should have used smaller increments but WTF, it was my first time
measuring
TA). What is the difference between TA and pH? I have a chem degree
some
a
technical answer is welcome. I haven't measured pH yet as my meter needs
new
batteries.

-Danno
.
--
email me at s_danno at msn dot com
---------------------------------------------------------