... adding 24% hydrochloric acid, then dissolved. (4) to neutral to take the sample solution plus excess 0.1mol / ... materials, concentration ratio, the acidity of the different products to control, generally: soft drinks 1.2 ~ 1.5g ... used for jams and jellies, to keep the products, pH value of 2.8 to 3.5 more appropriate. ... Add the jam, in addition to ...