What causes a flat sour taste in home canned tomato juice?
Flat sour taste is a common problem in home canned tomato juice. It is caused by bacteria that thrive on heat. Although it is not a health hazard, it makes the juice unpalatable. To minimize the chance of flat sour spoilage, tomatoes should be washed and rinsed thoroughly to remove garden soil which contains bacteria. In addition, after processing, place jars on rack to cool as rapidly as possible. Do not stack hot jars or cover with a towel, which slows the cooling. The bacteria that cause flat sour spoilage grow well in warm areas.