Presto 18qt this time, 50332 weight set. I PCed 4 quarts of strained tomato juice (put through Victorio, then through mesh strainer, boiled on stove before filling jars). There might have been a few teeny red specks in the canner water (3 qts) after PCing for 17 minutes (added 2 minutes to be safe, we're at 997ft to the foundation) at 10psig. I figured I was golden - the weight set never stopped rocking, I had the burner set to High (10) to heat the water and the jars, turned it to Off when it started boiling, filled the jars, and then turned it to 8 and left it there through the 10 minute vent, coming to pressure, 17 min processing time, then of course turned it Off when time was complete, after depressurization and the lid lock dropped I removed the weight, then opened the lid, waited 10 more minutes to remove the jars. HS was 1" following Ball Complete instructions for Tomato Juice. Of course I acidified - 1/2tsp CA per quart.

I reduced the strained solids (mixed with more tomatoes I milled and didn't strain) by about 1/3 for what I thought was "thin" sauce per NCHFP. Same procedure except this time I left 3/4" HS b/c I was not sure whether Ball 1" was correct or I should go with NCHFP (which says 1/2" for juice and 1/4" for sauce). I think every jar siphoned b/c the water was yellowish and I have tomato gunk around the threads and down the sides of the jars. I did add a little water to the canner, maybe a pint at most, to replace what evaporated (vented) while doing the juice. It did seem to be a little low when I opened the canner after PCing the sauce. Maybe I should have dumped the water out after that batch and refilled after measuring 3 qts per the manual.

So did my sauce siphon b/c I had too much (or too little, according to Ball Complete) HS? Because the sauce was thicker? B/c I had too little water in the canner? B/c my glass top burner cycles, even though I didn't touch the control and the weight/pressure stayed over 10 psi (11 by gauge, I do think I saw it hit 12 at one point)?

I just took the rings off, even the quarts of juice seemed a little sticky so they probably siphoned too, just the clear stuff not the pulp.

Granted I use a dial gauge. Once I'm up to pressure, I turn my burner down to about 2. 2 keeps it at pressure.

You don't get siphoning turning the heat down after it's at pressure? I thought that was a major cause of siphoning - my thread from last fall I said I was at 7 and turned down to 6.5, Dave told me that likely caused it.

From NCHFP:

"After the canner is completely depressurized, remove the weight from the vent pipe or open the petcock. Wait 10 minutes; then unfasten the lid and remove it carefully. Lift the lid with the underside away from you so that the steam coming out of the canner does not burn your face."

Whose HS recommendations should I use in the future though - Ball Complete or NCHFP? I can't believe they're so different!

As far as after processing, yes the NCHFP site is correct to remove the weight and wait 10 minutes before removing the lid. FWIW, my Ball Complete Book of Home Preserving does say to remove the weight and wait 10 minutes too.

I also have a glass top stove and I move my canner off the burner to a cool burner and don't have issues with siphoning. I think siphoning mostly comes from not enough HS and a rapid decrease in temps. If you continue to have problems, next time remove the weight and wait 10 minutes, remove the lid and wait another 10 minutes before removing the jars.

It really shouldn't matter if you have the heat cranked since the weights will just vent the extra pressure and the temperature should remain the same. However, I do wonder if all the furious boiling water might be jiggling the jars too much. Could the jars be giggling enough to splash the contents up on the lid?