Removing CO2 prior to testing TA

...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

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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?

Reply to
Negodki
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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

Reply to
Clyde Gill

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

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Reply to
Ed Marks

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. :)

Reply to
Negodki

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

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

Dave

Yep!

-- Dave

**************************************************************************** Dave Breeden snipped-for-privacy@lightlink.com
Reply to
David C 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.

Reply to
Rene

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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

Reply to
Tom S

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