K A S H R U T . C O M_©

September 20, 2017 from Hakhel Organization:
FLOUR ALERT! In past years, after baking challah or kneading the dough, some have noticed insects in the challah or dough, and have had to dispose of the food and their hard work with it. We are not currently aware of any current insect advisory with respect to flour--however, "an ounce of prevention" is in order as the heavy challah and cake baking season begins. Below are the recommendations of a Rav HaMachshir expert in this field:

1. Especially buy flour from a store that has a high product turnaround so that the flour has not been sitting on a shelf or in storage for a while. 　
2. Even if the flour is ‘pre-sifted’--the label may also state that it is recommended to be sifted. One should not treat this recommendation lightly--as in the post-summer period that we are in there are higher levels of infestation. 　
3. The specially packaged ‘Wonder Flour’ is an excellent choice--because of the excellent seal that is placed around the flour when produced. 　
4. Flour should be sifted with a 70 mesh sifter. The electric Pelematic sifter is highly recommended for large amounts. 　
5. Since whole wheat flour cannot be sifted, one should place several samples of the flour on a plate and then scatter the flour around and look for black or crawling objects.