I don’t care if freezing doesn’t kill the bugs. The flour will be used to cook something. It will go into a baked item or be used to coat something for frying. Now I am not saying we shouldn’t take precautions against infestation. What I am saying is there has to be a balance. At what cost (in money, time and effort) is it worth it to make something absolutely safe? Personally, I don’t want to lose focus.
Keep in mind is that temperature fluctuations can be as bad as a sustained high temperature. I don’t claim to know the science but what I have found is that food stored at a constant 80 degrees will hold better than food stored at 30 in the winter and 90 in the summer. Anecdotally, this is especially true of canned goods I have stored in my home.
Among the original residents was famed television newscaster Tom Brokaw, who lived there when he was just a boy along with his family. Brokaw wrote fondly about his time at Fort Igloo in his memoirs, “While my Dad was at work in igloo, Mother was at home with three boys under the age of four. My youngest brother, Mike, had been born at the base, just fifteen months after Bill. We were confined to that small space during the harsh winter months, and yet I cannot recall any sense of hardship or any bickering between my parents. As my mother likes to remind me, "Everyone was in the same boat."
Freeze-dried food is nothing new. As early as the 13th century, the ancient Quechua and Aymara people of Bolivia and Peru pioneered a form of the process by exposing potatoes to the freezing temperatures of the Andes overnight, then drying them in the sun. In 1937, Nestlé used industrial technology to create the world’s first freeze-dried coffee, and in the 60s and 70s, the US military shipped freeze-dried food rations to the troops in Vietnam.