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:
> 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
> > ---------------------------------------------------------
> >
> >
> >
>
>