I just tried this and was maybe at 195 for the first batch. I had one bottle go kablooie and the caps on two others fly off. Second batch was at about 170-175 and was fine. Is that high enough to have done the job?
The whole idea of pasteurizing is to kill the yeast. which, if you read some of the threads on HBT can be done at 100F-125F, but that would probably take several hours with your carbonated cider, and who wants a brew day to last that long? Also, you've got to do this fairly soon after reaching the proper carbonation - so don't wait too long, from what I've read. If you look in the past threads, it can be as low as 150F (lower in some cases) - as long as you leave it in long enough so that the whole bottle reaches the set point - I'd recommend using one of those remote thermometers (where you just use a probe in the bottle) and put that bottle in the center of the pile - then make sure that you keep it at the set temperature for the proper amount of time - that means wasting one bottle of cider (which you can drink, even tho it will be flat, not sparkling), but at least you have a liquid of the same density as the rest of the bottles ..... you can stick the probe thru a cork so that the water heating environment isn't affecting the temp of an open bottle. Remember, you have to heat a glass bottle to bring up the temps of the liquid inside of that bottle - it takes time because both don't heat at the same speed, the bottle heats slower than the liquid inside, that's why I put a thermometer in the water and a second thermometer (the one with a probe) in the cider bottle. That tells me when the cider has reached the proper temp for pasteurization. I followed Pappers' instructions for part of this - other than the temp/time itself, using the ideas of others for measuring the temps, and my cider worked out great. I first brought the water up to temp, put the bottles in one at a time, and didn't start the timer until the water temp was back up to my set-temp. I maintained the set-temp throughout the whole set-time. I don't drink cider but the wife does, so I haven't made it in a few years or so - she says it gets better with age! I'll try to backtrack this thread and see exactly what the temps and time are supposed to be and edit this when I come up with a more explicit answer ;>)
NOTE: Be sure you have something between the bottom of the bottles & the bottom surface of the water pot. I use a canning plate (looks like a false bottom, but the holes in it are about 1/2" in size), although some posters have said that a rag will do. Since I used an old canner pot for pasteurizing (you can tighten down the top to prevent bottle bomb problems) we still had the plate that goes with it - just take out the rubber pop-valve so you can put the probe and long-stemmed thermometer in!
OK, I read a few pages toward the front of the thread - Pappers says he puts room temp bottles into 190F water for 10 minutes and it usually drops the water temp to about 160F, so he apparently doesn't keep heat under it all the time. Another poster says 160F for 20 min. You might read pages 3&4 because supposedly certain yeasts are not affected by this pasteurization technique. On pg 7, post #61, Joe Sponge shows some calcs he found for pasteurizing
water as low as 128F/56 min., 140F/5.6 min., 152F 5.6 min as well as a lot of other good info if you have a scientific mind (I dont!). I believe I used 165F/20 min. as a set point/time, and had/have had NO bottle bombs. I think you went over the 190F too much and also you need to be sure you didn't over-carbonate as that will also cause bottle bombs, volcanoes/foam fountains, etc.
Just be sure you read thru the first 10 or 15 pages of this thread (and even take a look at the links to some other threads), so you're aware if the risks involved in pasteurizing! If you have questions, ask Pappers - he's the mod of this thread AFAIK.
BTW, one poster - cyberbackpacker - says that he visited Yeunglings Brewery and they told him that they pasteurize their
beer at 140F/12 min.
MT2sum