Aqueous solution of potassium metabisulphite, pale straw yellow in color and with a characteristic odor of sulfur dioxide. It is an indispensable additive in the oenological sector as it performs various functions: ability to coagulate during the clarification phase; ability to solubilize polyphenols; antiseptic capacity against undesired microflora; acidifying function; antioxidant and antioxidant capacity.