[level h3=”White flour” gen=” gb=”1″ us=”1″ il=”2″]
Sift the flour through a fine sifter (70 mesh, i.e., 70 holes in a linear
inch = 14 holes in ½ centimeter). It is best to buy a sifter (manual or electric) with a certification by a kashrus organization as to the density of the holes.
If many insects or worms are found in the sifter after sifting, it is recommended not to use the flour (Illustrations 257, 258).
Cleaning the sifter
After each use the sifter should be banged out well to remove remnants of flour. Every six or eight weeks, it should be taken apart, soaked in soapy water, and rinsed well. (If the sifter is kept in the refrigerator or freezer in a plastic bag, it does not have to be cleaned.) To facilitate putting the sifter back together, put the mesh part into a bowl of hot water and re-attach it to the plastic ring while it’s still hot. Flour sifters should not be stored in a cardboard box, because book lice may develop in the cardboard.
Flour that is ground immediately after Pesach (in Israel) is more likely to harbor infestation, due to the insects that proliferate in the idle machinery during Pesach.
Sifted flour can be stored in the refrigerator for up to a month, and in the freezer indefinitely.
[level h3=”Whole wheat flour” gen=” gb=”1″ us=”1″ il=”2″]
1.Whole wheat flour, which is coarser than white flour, does not go through a 70-mesh sifter. The best approach is to use special “bug-free” whole wheat flour that is produced under reliable supervision and is then either vacuum-packed, kept refrigerated, or packaged with nitrogen gas. The flour must have the approval of a certified kashrus organization attesting that it is bug-free and does not require sifting.
2.If such flour is not available, sift the flour through a 50-mesh sifter (50 holes per linear inch = 10 holes in ½ centimeter), spread out the flour that remains in the sifter on a white surface in a thin layer and check it well. If infestation or webbing is found, do not use the sifted flour, because smaller insects may have gone through the sifter.
Whole wheat flour that was milled in a regular mill must be sifted, even if you bought it on the same day it was ground, or even if it was kept refrigerated from the time of milling. Do not rely on assurances from the shopkeeper or owner of the plant that it does not require sifting.
Note: to kashrus mashgichim: At the end of the third volume of the sefer Bedikas HaMazon K’Halachah in Hebrew there is a detailed appendix about flour mills
