TA test not going as expected?

[jasonclick]

newbie winemaker question... i put together 2 wines last year... the white (muscadine) in August and the red (cab sav) October. Anyways after primary fermentation i transferred these to 5 gallon stainless kegs and haven't touched them since. Before i transferred them the white TA was 9g/L and the red was 7.5g/L.
I did a TA test this morning (Titratable Acidity Testing Kit from morewinemaking.com) and didn't get a color change from either. When i measured the pH of the wines with my pH meter, the white was 2.93 and the red was 4.04.
Any reason why the pH would be low but test shows no TA? maybe a need a refresher on how to do the test?
Help! I'm off today for our little hurricane happening so i'd like to get these wine chores done today.

 

[cmason1957]

Instead of trying to guess when the color change happened, put your ph meter to use. The color change happens at a ph of 8.2 so titrate until that point. Go slowly once you get close.

If your cab Sauv ph is 4.04,you probably need to add some tartaric acid, but let taste be the guide. I would assume it might taste a bit flabby and boring, but it might be fine.

 

[jasonclick]

thanks for the reply. i'll give another shot using the ph meter

 

[GreginND]

is your sodium hydroxide still good?

 

[jasonclick]

is your sodium hydroxide still good?

i'm not sure. i bought it about a year ago. so not sure the shelf life.

 

[Johnd]

i'm not sure. i bought it about a year ago. so not sure the shelf life.

At a year or more of age, it'd be worth every penny to get some fresh stuff, it loses it's potency over time and will give you TA levels that are not correct.

 

[Sailor323]

The published shelf life of N 10 NaOH is about 2 years. That being said, I just compared a 20 year old sample with a brand new one and there was no significant difference. You can Standardize your solution with Potassium Acid Phthalate. pH does not test for TA.