1,030. Sifting and Separating on Yom Tov

Shvisas Yom Tov 3:14

Even if flour was sifted and the bran removed on the day before yom tov, it may not be re-sifted on yom tov unless something like a pebble or a splinter fell into it. It is permitted to do so if one deviates from sifting in the usual fashion, such as by sifting on the back of the sifter or over a table.

Shvisas Yom Tov 3:15

On yom tov, it is permitted to remove grain from its husk or pulse from its pods, and then to wave over them with both hands as hard as one can in order to blow the undesirable portion away before eating. One may use a vessel that has compartments for this purpose but not a sifter or a strainer. Similarly, one who separates pulse on yom tov may do so in the normal manner into his lap or a pot but not using a strainer, a sifter or a board.