Along with Lab work I was also sampling and bottling but in this post I shall describe my time in the lab. It was to figure out the Brix (sugar level), TA (titrable acidity), and pH (acidity) of samples from different vineyards to decide when they should be picked.
Titrable Acidity is the amount of acid found the sample. It is figured out by taking a 5 ml sample of must (grape juice) and putting it with 25 ml of water. Next you put it on a magnetic stirrer and insert a pH reader. NaOH (sodium hydroxide) is slowly added through a burette until the pH is at 8.2. You put all of your numbers into this formula:
g/L = ml NaOH x normality NaOH x 0.075 X 1000
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Sample Volume (ml)
the final answer is grams of acid in 100 ml.
Brix was much easier to find out. I used an DMA 35 Portable Density Meter by Anton Paar. which just sucked up the grape juice and told you the amount of sugar in your sample.
pH was a also easy to get answers. You first calibrated the pH meter and then put the probe into your samples and the answer was given to you. Calibration was done by using 3 different samples one that had a pH of 7 followed by one with a pH of 4 and finished with a 10.
