What is an Acid test kit? How do I use it?

An Acid test kit allows the measurement of tartaric acid (the most important of the several acids present). A wine too high in acid is sharp and tart. One too low is flat or “flabby”. The acid test kit usually contains a container to put a measured sample of wine in, a color indicator and a neutralizer. Follow the directions of the kit to determine the acid content, then make any adjustments, if needed. The best time to measure and adjust is prior to adding yeast, and also before adding any sulfite to kill wild yeast. Adding a measured amount of water can reduce a must that is too high in acid. Adding acid blend (a balanced blend of tartaric, malic and citric acid) can increase one too low in acid. Consult a good reference book for further details.