The temperature factor TF, from a storage temperature in °C.
Garetz states the rule in words, "the rate of deterioration is halved for
every 15 °C (27 °F) drop in temperature", and publishes it as a table. As
a formula:
TF=2^ ((T − 20) /15)
This is 1 at the 20 °C the percent-lost figures are quoted at, 0.5 at 5 °C,
and 0.226 at the −12 °C of a home freezer. The article's worked example uses
0.228 there, read off its table. The exponential form some
implementations use, 0.39685 · e^(0.046210·T), is the same curve: 0.046210
is ln 2 / 15 and 0.39685 is 2^(−4/3).
The temperature factor
TF, from a storage temperature in °C.Garetz states the rule in words, "the rate of deterioration is halved for every 15 °C (27 °F) drop in temperature", and publishes it as a table. As a formula:
This is 1 at the 20 °C the percent-lost figures are quoted at, 0.5 at 5 °C, and 0.226 at the −12 °C of a home freezer. The article's worked example uses 0.228 there, read off its table. The exponential form some implementations use,
0.39685 · e^(0.046210·T), is the same curve: 0.046210 isln 2 / 15and 0.39685 is2^(−4/3).