Recommended headspace is 1 1/4".

NCHFP: "Fill jars with pieces and hot broth, leaving 1-1/4 inch headspace."

But if you had lots of siphoning that is normally caused by fluctuations in the pressure due to too many heat adjustments. Once you get siphoning out of the jar then the grease and particles that get on the jar rim often prevent sealing. You can always reprocess with new lids and clean jar rims if done within 24 hours.

Dave

Thanks digdirt! Next time I'll be more careful about headspace--I might have been a little shy of 1 1/4 inch.

My husband "mans" the canner and monitors the pressure, and he said there was no fluctuation. So I'm guessing it must have been a headspace issue.

Thanks again for your advice!

Could be but pressure fluctuations, enough to cause siphoning, can't really be "seen". ;-)

Even with eyeballs on the gauge - one reason why using weights is so much better than gauges. Once it is up to pressure all it takes is a infinitesimal drop for siphoning to happen. That's why if the heat level is changed in any fashion once it is up to pressure you'll get siphoning.

Dave

Interesting information, digdirt. We do use a dial gauge canner, so we certainly could have had some fluctuations that didn't register. We were set up in our garage, with the garage door open for ventilation. Outside temp was about 55, but not much breeze. Maybe that was part of our problem! I don't think we've canned before this late in the year.

Next year we'll definitely can our turkey(s) earlier in the year--we just ran out of time this fall! Lesson learned!