Ajmassa
just a guy
If your borderline color blind it just doesn't work. What's even worse is trying to do a manual titration. Just got off the phone with Vinmetrica. They had to walk me through rebuting the meter. Seems OK now but they recommended I do a final test with cream of tartar. See below:
pH test with cream of tartar
A quick way to check your calibration and pH accuracy is to measure the pH of a saturated solution of cream of tartar which has a pH of 3.56 at 25 degrees celsius:
a. Get pure cream of tartar (grocery store stuff is fine, provided it’s pure), or even better is reagent grade potassium hydrogen tartrate, also known as potassium acid tartrate or potassium bitartrate. Call it KHT for short.
b. Place about 1/4 teaspoon of KHT in 20 mL of distilled water. Mix well for about 30 seconds. You want to be sure the solution is saturated, i.e., everything that can dissolve, has dissolved. There should be some undissolved solid left.
c. Decant or filter the solution off the solids.
d. This solution has a standard pH of 3.56 at 25 degrees C (78 degrees F). It should be within 0.02 pH of this value at temperatures from 20 to 30 degrees Celsius. Discard after 24 hours.
Yikes. Sounds like work. And a trip to store. Just stick it in another wine you made that you know the ph of.