Some of the comments in this string include the news that small pressure cookers may not be safe for canning. This web site has a summary on the USDA uncertainty: [...]Note the use of verbs "may" and "can." "Later research published in journals has not resulted in an absolute recommendation either. Therefore, in the late 1980s the USDA published its recommendation to not use pressure saucepans (small cookers) for home canning."Bottom line: A bigger canner, the kind studied in the 1940s, holds heat longer and that *may* result in significantly different required processing times. Then again, subjecting jars to an hour of the temperature generated at 15 psi near sea level just might kill every living thing in even the smallest pressure cooker. In any case, if you were a pressure cooker manufacturer's lawyer, what would you recommend they say?Golly it would be swell if the USDA could arrive at definitive and useful canning advice, like it did back in the 1940s.