Dave Breeden ) wrote:

...have you removed all the CO2? That will falsely raise your TA values.

Dave,

1) Will adsorbed CO2 distort the pH value as well, or just the TA?

2) Can you (or anyone else) suggest a few methods that home winemakers might
use for this procedure.

I saw a few methods described at
http://groups.google.com/groups?q=re...rect.ca&rnum=4.

Not everyone has a vacuum pump handy, but the "wine whip" sounds promising.
Still, we only need to degas the sample that we are using to test the TA/pH,
right?

Would the following procedure work? Put the sample in an Erlenmeyer flask or
small wine bottle, and seal it with a rubber stopper. Shake the bottle
gently. Remove the stopper slowly. Seems like this would get rid of most of
the CO2 without any special equipment. Comments?

Would the following procedure work? Put the sample in an Erlenmeyer flask
or
small wine bottle, and seal it with a rubber stopper. Shake the bottle
gently. Remove the stopper slowly. Seems like this would get rid of most
of
the CO2 without any special equipment. Comments?



That's about how I do it, but just use the fat of my hand to seal the flask
and shake it "not-so-gently".

After several times (no pressure builds) it gets pretty well degassed.

clyde

I've been following a procedure from a basic wine analysis video from
Southwest Missouri State Univ.: bring 100ml of distilled water to a boil in
a microwave, then pipette in 5 ml of wine - this immediately degasses the
sample - you'll visually see the CO2 being released. Then put the sample in
a cool water bath or refrig to get it to room temp before testing.

Hope that helps,

Ed


"Negodki" wrote in message
...
Dave Breeden ) wrote:

...have you removed all the CO2? That will falsely raise your TA values.

Dave,

1) Will adsorbed CO2 distort the pH value as well, or just the TA?

2) Can you (or anyone else) suggest a few methods that home winemakers
might
use for this procedure.

I saw a few methods described at

http://groups.google.com/groups?q=re...rect.ca&rnum=4.

Not everyone has a vacuum pump handy, but the "wine whip" sounds
promising.
Still, we only need to degas the sample that we are using to test the
TA/pH,
right?

Would the following procedure work? Put the sample in an Erlenmeyer flask
or
small wine bottle, and seal it with a rubber stopper. Shake the bottle
gently. Remove the stopper slowly. Seems like this would get rid of most
of
the CO2 without any special equipment. Comments?

"Clyde Gill" wrote:

That's about how I do it, but just use the fat of my hand to seal the
flask
and shake it "not-so-gently".

After several times (no pressure builds) it gets pretty well degassed.

Thanks Clyde. I have NOT been degassing my samples, which may explain why my
taste tests don't always correspond to the numbers. I shall do so in future.

I figured "shake it gently" so it doesn't spurt all over the place when I
move my thumb, but I guess it doesn't have the same amount of CO2 as a
bottle of soda pop.

Hi: The established chemical procedure is to boil the solution to be
titrated for about 5 min. Cool quickly and titrate.

Joe
"Negodki" wrote in message
...
Dave Breeden ) wrote:

...have you removed all the CO2? That will falsely raise your TA values.

Dave,

1) Will adsorbed CO2 distort the pH value as well, or just the TA?

2) Can you (or anyone else) suggest a few methods that home winemakers
might
use for this procedure.

I saw a few methods described at

http://groups.google.com/groups?q=re...rect.ca&rnum=4.

Not everyone has a vacuum pump handy, but the "wine whip" sounds
promising.
Still, we only need to degas the sample that we are using to test the
TA/pH,
right?

Would the following procedure work? Put the sample in an Erlenmeyer flask
or
small wine bottle, and seal it with a rubber stopper. Shake the bottle
gently. Remove the stopper slowly. Seems like this would get rid of most
of
the CO2 without any special equipment. Comments?

I don't boil that long, I boil less than 10 seconds. I pull the
sample with a glass syringe, so the partial vacuum always indicates
whether the sample contains gas. The shorter boil seems to work for
me. I use a microwave and cool the sample in cool water before
measuring.
Regards,
Joe


"Joe Yudelson" wrote in message ...
Hi: The established chemical procedure is to boil the solution to be
titrated for about 5 min. Cool quickly and titrate.

Joe
"Negodki" wrote in message
...
Dave Breeden ) wrote:

...have you removed all the CO2? That will falsely raise your TA values.

Dave,

1) Will adsorbed CO2 distort the pH value as well, or just the TA?

2) Can you (or anyone else) suggest a few methods that home winemakers
might
use for this procedure.

I saw a few methods described at

http://groups.google.com/groups?q=re...rect.ca&rnum=4.

Not everyone has a vacuum pump handy, but the "wine whip" sounds
promising.
Still, we only need to degas the sample that we are using to test the
TA/pH,
right?

Would the following procedure work? Put the sample in an Erlenmeyer flask
or
small wine bottle, and seal it with a rubber stopper. Shake the bottle
gently. Remove the stopper slowly. Seems like this would get rid of most
of
the CO2 without any special equipment. Comments?

Negodki ) wrote:
Dave Breeden ) wrote:

...have you removed all the CO2? That will falsely raise your TA values.

Dave,

1) Will adsorbed CO2 distort the pH value as well, or just the TA?

Yes, but wine is highly buffered (50% wine, 50% water has the same
pH reading as 100% wine), so the effect is negligible.


2) Can you (or anyone else) suggest a few methods that home winemakers might
use for this procedure.

Find a way to draw a vacuum, or boil the sample, or shake it until
no more Co2 froth occurs.

Dave


Would the following procedure work? Put the sample in an Erlenmeyer flask or
small wine bottle, and seal it with a rubber stopper. Shake the bottle
gently. Remove the stopper slowly. Seems like this would get rid of most of
the CO2 without any special equipment. Comments?

Yep!



--
Dave
************************************************** **************************
Dave Breeden

Joe,
Might be my logic is off, but it seems that boiling the sample for 10
minutes would effectually concentrate the sample and alter the results of
your test. I have put my samples in the microwave usually in a water glass,
brought it to a good boil and then tested. My other method is to stir
vigorously or shake the heck out of it in a bottle.
John Dixon
"David C Breeden" wrote in message
...
Negodki ) wrote:
Dave Breeden ) wrote:

...have you removed all the CO2? That will falsely raise your TA
values.

Dave,

1) Will adsorbed CO2 distort the pH value as well, or just the TA?

Yes, but wine is highly buffered (50% wine, 50% water has the same
pH reading as 100% wine), so the effect is negligible.


2) Can you (or anyone else) suggest a few methods that home winemakers
might
use for this procedure.

Find a way to draw a vacuum, or boil the sample, or shake it until
no more Co2 froth occurs.

Dave


Would the following procedure work? Put the sample in an Erlenmeyer flask
or
small wine bottle, and seal it with a rubber stopper. Shake the bottle
gently. Remove the stopper slowly. Seems like this would get rid of most
of
the CO2 without any special equipment. Comments?

Yep!



--
Dave

************************************************** **************************
Dave Breeden

You measure 5 ml sample, then boil. The idea is that the acids are not
volatile, it doesn't matter whether the sample afterwards is
concentrated.
I agree 10 min is abolutely not necessary for wine.

Rene.
"J Dixon" wrote in message t...
Joe,
Might be my logic is off, but it seems that boiling the sample for 10
minutes would effectually concentrate the sample and alter the results of
your test. I have put my samples in the microwave usually in a water glass,
brought it to a good boil and then tested. My other method is to stir
vigorously or shake the heck out of it in a bottle.
John Dixon
"David C Breeden" wrote in message
...
Negodki ) wrote:
Dave Breeden ) wrote:

...have you removed all the CO2? That will falsely raise your TA
values.

Dave,

1) Will adsorbed CO2 distort the pH value as well, or just the TA?

Yes, but wine is highly buffered (50% wine, 50% water has the same
pH reading as 100% wine), so the effect is negligible.


2) Can you (or anyone else) suggest a few methods that home winemakers
might
use for this procedure.

Find a way to draw a vacuum, or boil the sample, or shake it until
no more Co2 froth occurs.

Dave


Would the following procedure work? Put the sample in an Erlenmeyer flask
or
small wine bottle, and seal it with a rubber stopper. Shake the bottle
gently. Remove the stopper slowly. Seems like this would get rid of most
of
the CO2 without any special equipment. Comments?

Yep!



--
Dave

************************************************** **************************
Dave Breeden

Rene,
Here's what I was thinking- you start out with let's say a cup of must
and boil 10 minutes. Now you end up with 1/2 cup after boiling and then take
your 15ml sample of must. Have you not theoretically double the acid content
per volume? I suppose if you started out with 15ml and then boiled it then
you would have the same amount of acid in the end no matter the end volume,
but I don't think that is what he was saying.
John Dixon
"Rene" wrote in message
om...
You measure 5 ml sample, then boil. The idea is that the acids are not
volatile, it doesn't matter whether the sample afterwards is
concentrated.
I agree 10 min is abolutely not necessary for wine.

Rene.
"J Dixon" wrote in message
t...
Joe,
Might be my logic is off, but it seems that boiling the sample for
10
minutes would effectually concentrate the sample and alter the results
of
your test. I have put my samples in the microwave usually in a water
glass,
brought it to a good boil and then tested. My other method is to stir
vigorously or shake the heck out of it in a bottle.
John Dixon
"David C Breeden" wrote in message
...
Negodki ) wrote:
Dave Breeden ) wrote:

...have you removed all the CO2? That will falsely raise your TA
values.

Dave,

1) Will adsorbed CO2 distort the pH value as well, or just the TA?

Yes, but wine is highly buffered (50% wine, 50% water has the same
pH reading as 100% wine), so the effect is negligible.


2) Can you (or anyone else) suggest a few methods that home
winemakers
might
use for this procedure.

Find a way to draw a vacuum, or boil the sample, or shake it until
no more Co2 froth occurs.

Dave


Would the following procedure work? Put the sample in an Erlenmeyer
flask
or
small wine bottle, and seal it with a rubber stopper. Shake the
bottle
gently. Remove the stopper slowly. Seems like this would get rid of
most
of
the CO2 without any special equipment. Comments?

Yep!



--
Dave


************************************************** **************************
Dave Breeden

"Negodki" wrote in message
...
Dave Breeden ) wrote:

...have you removed all the CO2? That will falsely raise your TA values.

Dave,

1) Will adsorbed CO2 distort the pH value as well, or just the TA?

2) Can you (or anyone else) suggest a few methods that home winemakers
might
use for this procedure.

I saw a few methods described at

http://groups.google.com/groups?q=re...rect.ca&rnum=4.

Not everyone has a vacuum pump handy, but the "wine whip" sounds
promising.
Still, we only need to degas the sample that we are using to test the
TA/pH,
right?

Would the following procedure work? Put the sample in an Erlenmeyer flask
or
small wine bottle, and seal it with a rubber stopper. Shake the bottle
gently. Remove the stopper slowly. Seems like this would get rid of most
of
the CO2 without any special equipment. Comments?

Just put the sample in the microwave and heat it until it just starts to
boil. The dissolved gases will all be gone.

Tom S