I have been searching for the simplest automated / online tools that would let me calculate the "time-to-sterile" for hot water immersion. I can probably fake steady-state calculations, but that's not what we're looking for.
I did turn up useful information in my searches...
From my close, personal friend (Wikipedia):
"... There are two main types of pasteurization used today: High Temperature/Short Time (HTST) and "Extended Shelf Life (ESL)" treatment. ...
... is forced between metal plates or through pipes heated on the outside by hot water, and is heated to 71.7 °C (161 °F) for 15–20 seconds. ...
The HTST pasteurization standard was designed to achieve a 5-log reduction, killing 99.999% of the number of viable micro-organisms in [milk]. This is considered adequate for destroying almost all yeasts
, mold, and common spoilage bacteria ...
And, from my friend that I would like to be closer, and more personal (HBT):
"... looked through "Brewing, Science, and Practice" where I remembered reading about some pasteurization info.
Here's some quick info:
at 53C minimum time to kill population 56 min
at 60C minimum time to kill population 5.6 min
at 67c minimum time to kill population .56 min
And, because I need to dink around more on my computer than sleep, I found a TON of great calculations that I can't do any more, and settled for a simple conversion (thank you, Excel...):
53C = 128F
60C = 140F
67C = 152F
[C is degrees Centigrade, not Calories.
F is degrees Farenheit, not Frankenstein.]
So, a water bath LONG enough at a CONSTANT temperature, will do it. Steady-state is easy: Add a pound of ice and a pound of boiling water, mix well, and you have 2 pounds at 50C. We just can't mix the hot water INSIDE the bottles, so we have to wait. Is it done yet? Is it done yet? Is it don... sorry.
I'm still looking for the temperature -vs- time calcs (easy enough for me to do w/out relearning Biot's numbers, Fourier transforms, or how to use the charts from somebody who's name starts with an H... Whew. I need a cider again.
Failing that, you could do one of two things:
1) get the bottles swirling and turning, making the temperature more homogenous inside, approximating a solid with good heat conductivity, or
2) Put a thermometer into an open bottle and hope for the best.
I think I'm going to try the last one. Sweet(er) cider, here I come.