PH vs TA

[Scooter68]

"Some chemistry text explains what it is really measuring. I'd dig to find the reference but I have a day job, it is dark out, my glass of wine is empty and it is my bed time."

Well said - The topic is quite deep and between chemists and Vintners they can really tie a mind into knots.

 

[morettisf]

Go with PH as your indicator for stability and adjust your Free SO2 accordingly. Sometimes wines can have a nice high TA number but the PH is off and high as well. Here's a great PDF that has a chart on how to adjust your SO2 doses for the PH level you read. See p.2 Vintner's Vault PDF

 

[Tnuscan]

Yes... I agree this has almost driven me nuts, and I have about driven ibglowin nuts.

But hey in't that what ibglowins are for?

 

[ibglowin]

Nah, trust me you are nowhere near the top!

 

[Johnd]

C'mon folks, you can make wine by monitoring only pH, but we all know that good winemakers pay attention to both. Don't talk yourself into taking the easy route, work your pH and TA together, do the best you can. Some wines will trap you with a low pH and TA, but that's a grape problem and a chance to grow and learn. Tackle it. Do the chemistry. Have fun solving the problems. Get fresh chemicals now, judgement day is at hand!

 

[Scooter68]

Yeah, I may check TA but honestly pH and a healthy tongue are the best tools. And in practical terms - As long at my pH meter is accurate to within .05 - good enough. We are shooting at moving target with wine. I'm not making any wine that will be destroyed or harmed if my meter is a little off - I'm more concerned about what it tastes like when I pop that cork - so you get it 'in range of your target' and go for it. Until someone has an inexpensive test that will tell me which acids are there and how much of each...

 

[ibglowin]

See my post #14 on this tired old thread. Ignore TA at great risk. You must manage both. It takes years and years to calibrate a mouth. It takes 10 seconds to calibrate a pH meter.

 

[Tnuscan]

I agree that knowing the pH is all that is needed to make a nice wine, how much SO2, where you need to be for MLF, how long you can cellar your wine etc. but the TA will help you DIAL it all in, gives you a better picture on how and why.

TA will help inform you which route you can take to bring the wine into balance. Every wine I drink that is off a little is usually within a decent pH range but the TA is way up or down.

You can do it by taste. I know someone that owns a successful winery, and has won many medals, and he just goes by pH and taste. And they are all balanced wines.

Every wine that I love to drink is always "IN BALANCE".

This is what I gather from my studies, now lets see if I can make a nice wine this fall. lol

 

[Scooter68]

OK let me ask this again - In doing a TA test with a pH meter I'm using a .2 normal Sodium Hydroxide reagent. What sample size do I use? 10ml or 15ml (Undiluted -clear must) I used a 15ml and my TA was pretty high(8ml) = .8 Obviously this would be the case if the proper sample size is 10ml. 5ml isn't big enough to get my meter into 10 or 15 will work.


I ask because when I tried to check the precise procedures my searches return all kinds of directions from 5ml straight must to 15ml diluted with 'Xml' of distilled water or even 'neutralized distilled water' I have issue with doing the TA but part of the issue is that directions seem a bit squirrely. Guess I could go look at a kit but again there seem to be different approaches.

Thanks - Just trying to use TA to check the calibration of my tongue

 

[ibglowin]

If you purchase a TA kit follow the directions. If you just cobbled together regents and so forth use the universal TA formula:

TA as tartaric acid (g/100 ml) = (V) (N) (75) (100) / (1000) (v)


V = ml of sodium hydroxide solution used for titration
N = Normality of sodium hydroxide solution
v = sample volume (ml)


If you want the most accurate TA reading you start with distilled water that you have added NaOH to until the pH is 8.2. I have done enough TA's both ways and the difference is only a drop or two of NaOH which is why you can use regular distilled water if you want.

 

[Tnuscan]

OK let me ask this again - In doing a TA test with a pH meter I'm using a .2 normal Sodium Hydroxide reagent. What sample size do I use? 10ml or 15ml (Undiluted -clear must) I used a 15ml and my TA was pretty high(8ml) = .8 Obviously this would be the case if the proper sample size is 10ml. 5ml isn't big enough to get my meter into 10 or 15 will work.


I ask because when I tried to check the precise procedures my searches return all kinds of directions from 5ml straight must to 15ml diluted with 'Xml' of distilled water or even 'neutralized distilled water' I have issue with doing the TA but part of the issue is that directions seem a bit squirrely. Guess I could go look at a kit but again there seem to be different approaches.

Thanks - Just trying to use TA to check the calibration of my tongue

Ok, if your using 0.2 then pull 15 cc or ml of your must or wine. Rinse syringe with distilled water, pull 10 cc or ml of the 0.2 normal.

Add 0.2 normal until color change or pH of 8.2

Each cc or ml will be your percentage -- 3 cc/ml =30%, 7 cc/ml = 70%

Using 0.2 normal you need to keep the must/wine sample at 15 cc/ml every time.


EDIT: this works with 0.2 normal (ONLY)

 

[Scooter68]

Thanks - Nice thing about using the pH meter - color of the wine does not matter.

But one question on that - Distilled water has it's own pH unless you adjust it to 8.2 won't that skew the test? (That was the guidance on at least one other document I found) Again using a pH meter the color of the wine doesn't matter, I'm watching meter numbers not the color and I'm not using the Phenolphthalein Color Solution either)

Personally I think using the pH meter for TA testing is well worth then investment - More and more I hear people leaning of pH as the required test to be sure your wine will keep. So if one is going to invest in a pH meter just get the Sodium Hydroxide and have the results of both tests quickly.

Note to all: - I got some oral syringes (10ml) free at Walmart Pharmacy today They just gave me 4 of them along with 4 Five ml syringes as well.

 

[Tnuscan]

Yes it will change it, I deleted that info in my last post. Every time something is added to the sample , it has an effect. I just went and checked and the addition of 20ml of the distilled water changed the 10ml of wine from 3.4 to 3.3, that along with a couple extra drops of NaOH could make unwanted mistakes.

 

[Scooter68]

Thanks - You are not the only one to do that. Same directions are on several sites including the directions on one vendors site for using their TA test kit.

 

[Tnuscan]

I purchased several different small box kits for testing acids in wine. Each were from different suppliers, each had different formulas to reach the end point. I remember having one that was giving me results that were odd. I called the company the man I was speaking with asks me to describe the small bottle. When I did he said that it had to be older than 5 years because they had replaced the label. lol

I wanted to share this because, if your going to test make sure your regents are fresh. I've stopped buying the small kits and now purchase from larger suppliers. Some of this stuff sits on the shelves too long.