Testing for TA

[pkeeler]

Ok, I have a pH meter which makes testing red wines easy. However, to save NaOH solution (and wine), it makes sense to use like 10 ml of wine, and some 8.2 pH dilution fluid to cover the probe. Got it. However, I've had a tough time making 8.2 solution from distilled water and NaOH. First, the distilled waters I've tested don't show as 7.0 pH. Does the lack of any ions throw off the pH meters?

I also think it is the lack of buffer of any kind that makes adjusting DI water to 8.2 tough (or maybe I'm a spaz). Why not use tap water? If the pH of the dilution solution is 8.2, does it matter what it is?

Sorry for such technical questions in the beginners forum, but I couldn't find a "Vintner's Science" forum ;-)

I have a few wines going, and if I bring out the pH meter, I'd like to sample them all. Today, I finally got some water to read 8.2 and used it to read a sample. Ok, but now the water wasn't 8.2 anymore (must have got a drop of wine in there or something). Instead of making more solution, I simply poured my finished sample (at 8.2 pH) into the next sample to dilute it. Anything wrong with that? Results seemed to work. Even did a commercial wine last and the TA was reasonable.

 

[Randoneur]

Distilled water has a pH somewhere around 4.9 because it absorbs CO2 out of the air. The rest is beyond me, I don't know how to make buffers.

 

[djrockinsteve]

Be sure you ph meter is currently calibrated. You may use tap water as long as it's reasonably clean. Strive to have as close to 10ml sample as even a few drops more will give you a different reading. It's not an exact science wine making but getting close is fine.

There is a tutorial section on here about acid readings with a ph meter if you haven't seen it yet,

http://www.winemakingtalk.com/forum/showthread.php?t=11244

I like using the small plastic clear cups (similar to the ones you get with NyQuil) for my tests. The 10ml mark is on mine and is (after several tests) acurate, it is wide enough for my meter to fit in and cover the probes plus it is deep enough to hold the Sodium Hydroxide needed to reach the 8.2 reading.

Keep things simple and use your tap water, cool as hot would go thru your hot water tank. Lots of minerals in there.

 

[pkeeler]

The cups from medicine is a good idea. I switched to a shot glass; shows where my mind is LOL

 

[Tom]

The cups from medicine is a good idea. I switched to a shot glass; shows where my mind is LOL

LOL U fit right in