Work out come up time for retort instantly with clear inputs, formula shown and shareable results.
In the straight-line portion of a heat penetration curve, time is fh x log10(g0/g), where g is the difference between retort and product temperature. The heating rate index fh is the time for that difference to fall by a factor of ten and is determined experimentally for each container size and product.
Heat penetration
Time = fh x log10((T_retort - T_initial) / (T_retort - T_product))
Retort process schedules must be established from measured heat penetration data at the slowest heating point by a recognised process authority.
The driving temperature difference shrinks as the product approaches retort temperature, so the approach is asymptotic. Reaching within 1 degree takes as long again as reaching within 10.
Yes, and it can be significant at retort temperatures. Full process design integrates lethality from the start of heating, which is why measured heat penetration data is required.