Used to check acidity levels of juice. The kit contains plastic syringe, testing cup, sodium hydroxide solution, phenolphthalein color solution and 2oz of acid blend. Dont let the big words scare you! It is easy to use. Simply use the syringe to draw off a sample (15 cc) of the juice and put into the small measuring container. Add 3 drops of the color solution. Wash out the syringe and draw 10 cc of Sodium Hydroxide. Add it slowly to the container of juice. The juice will turn dark - continue to add until it stops changing color. White wines will change to light red and red wines turn bluish grey. Check the amount of cc that were used from the syringe. Each "cc" of Sodium Hydroxide used indicates percentage of acid. Therefore, if it takes 5 cc to attain the color change, the acid is .5%. Wine juice contains 3 main acids: malic, citric and tartaric. These 3 acids are blended together and sold as Acid Blend. 1 oz of acid blend to 6 gallons of must will increase the acid by .15% Desirable acids levels: Fruit Wines .60% Red Wines .65% White Wines .75%