Wine Volatile Acidity
Acetic acid is commonly formed during yeast growth in the early stages of fermentation. The rate and amount of acetic acid formed is partially dependent on the pH, sugar levels, available nitrogen, and temperature of the system. Typical VA levels post-fermentation range from 0.2 - 0.4 g/L. Any level higher could indicate microbial involvement and potential spoilage.
Below are the most common products measuring volatile acidity during the wine making process.
A variety of titrations systems are available including one that is programmed with only wine methods including volatile acidity, total titratable acidity, formol number, and free and total sulfur dioxide. Titration systems are available with 1 or 2 analog input boards that allow multiple sensors to be used. These systems can also be configured to have one or two dosing pumps. Having multiple dosing pumps allow for the use multiple titrants.
For high throughput some of the titration systems can be connected to an auto sampler for automated analysis of multiple samples.
A variety of pH electrodes are available that include application specific versions made specifically for grape juice and must. These versions feature a ground glass junction with a plastic sleeve. These features are part of Hanna CPS (clogging prevention system) technology to prevent clogging of the reference junction by solids found in grape juice and must.
In this category are pH calibration buffers including pH 8.2 used in the titration of volatile acidity, total titratable acidity and Yeast Assimible Nitrogen. The pH calibration buffers are available in a variety of sizes from single use sachets to bottles.
In this category are the solutions used to maintain pH electrodes that are used in volatile acidity titrations. These solutions include reference electrolyte fill solutions, storage solutions and application specific cleaning solutions used to remove wine stains and deposits.