How can I know if I need to sift flour in my country (Ecuador). I’ve been sifting for a few months and haven’t found anything. Is there ever a point when I can stop sifting?
It is hard to know without doing a thorough analysis of the frequency of infestation in your place. Nonetheless, it is still a good idea to continue to sift.
At the very least, it is recommended to buy triple sifted flour and store it in the freezer.
See here for a similar question.