Hi, I pressure canned some beans this evening (10 psi for 90 min). The beans have been cooling on the counter for a while and are still warm to the touch (maybe about 40C but definitely not boiling). The beans are still bubbling – any idea what this is or why this is happening?
by yoctowatt
1 Comment
Water under low pressure boils at a much lower tempereture than at sea level (normal pressure). It’s not unusual to see your goodies still bubbling/boiling as they cool even thought the temp is well below 212℉/100℃. because of the lower boiling point in the vacuum sealed jar.
This is also why canning process times are increased at higher altitudes, the “boiling” water is at a lower temperature than it would be at sea level so the processing time has to be longer.
I commonly see this phenomonon even in thicker goodies that have been water bath canned, so never above boiling temp. Even things like pasta sauce may boil for 10 minutes or more after being put on the cooling rack because of the very low pressure/partial vacuum in the jar.
TLDR; Yeah, that’s fine, in fact you want to see that as it’s a good indicator of a good vacuum & good seal.
EDIT; [Bonus chart](https://vacmobiles.com/wp-content/uploads/2021/08/vapour-image-2.jpg). If your goodies are still boiling at <40℃ it shows you’ve made/got a real good vacuum seal. Good work!