Origin of flat sour
Examples from the Web for flat sour
Historical Examples of flat sour
This "flat-sour" is not harmful and must not be confused with "botulinus," which is harmful.
However, the taste and odor are so disagreeable you will have no desire to eat "flat-sour" canned goods.
Flat-sour often causes annoyance to beginners in canning some vegetables, such as corn, peas, beans and asparagus.