Ph and TA difference
 

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
---------------------------------------------------------

Ph and TA difference
 

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

Ph and TA difference
 

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.

Ph and TA difference
 

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
> ---------------------------------------------------------
>
>
>

Ph and TA difference
 

"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

Ph and TA difference
 

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
> > ---------------------------------------------------------
> >
> >
> >
>
>