Is there a good way to test the accuracy of the acid test kit. I am doubting my results. I tested some fresh white grape juice and it took 1.5 ccs of the reagent to get to the color change. It is the cheap baker and crosby kit sold by Midwest supply. The instructions say for each cc to the end point indicates .1% acid which would mean the juice is only .15. And that seems very low to me. I thought about testing a little distilled vinegar of a known value, (5%). Does that seem possible. I would have to dilute the vinegar with water to get it to something like .5% in order to test it. I really would like to know the real acid content of the juice before I start the fermentation. Need some sound scientific advice on this.