The acid testing kit comes with everything you need to take several tests a year. Taking a test at the very beginning of fermentation, just before you pitch the yeast, is a good habit because it is better to make adjustments before the fermentation rather than later on in the process. You can make adjustments all the way up to bottling time, but your adjustments will not be as beneficial as if you’d done them earlier in the process.
Grapes and other fruits have different levels of acidity and this level varies from year to year. A skilled winemaker adjusts the acid level of the wine must prior to fermentation. Correct acid balance eliminates the drinker’s perception of “off” flavors, inhibits bacteria, and is essential for healthy yeast. The BSG acid test kit instantly measures the acidic content in any wine or other liquid and provides a reading in measured in either the US Standard “Percent Tartaric Acid” or the European standard “Parts Per Thousand Sulfuric Acid”.
Acid content is measured by combining a small sample of wine, the acid indicator solution and the reagent solution. Reagent is added to the sample until a color change occurs and the amount of reagent used is calculated to provide the acid content.