Detartrated

Grape juice ... is the only fruit juice that cannot be concentrated immediately after pressing because of the presence of potassium salts, commonly called tartrates, in the juice that cannot be filtered or centrifuged out. They have to be detartrated by gravity, a process that usually takes about six weeks.

In a large plant in California, the juice is first stored in large tanks under refrigeration. It is then partially detartrated by the ion exchange process.

Freshly made concentrate should be detartrated by storage in a settling tank for a week or two before use.

The detartrated juice that is to be preserved by pasteurization must be treated with bentonite in order to remove proteins which form an undesirable haze upon heating.

In each case the coagulant was added to 200 ml of the detartrated floe.

The detartrated cold wine is filtered in Gasquet filters, with addition of filter aid if needed. The detartrated wine may or may not be pasteurized, as its condition may indicate.