One may crack nuts on Shabbat, even though this constitutes removing food from its casing. This is not considered Dash because Dash is a melakha that is done commercially in the field or factory at the end of the harvesting process. Examples of this include removing kernels of grain from stalks in order to sell them or bring them to a mill, or removing peas and beans from their pods in order to sell them to the masses. In contrast, Dash does not apply to a fruit that is normally removed from its outer layer before eating. Since nuts are normally cracked right before eating, doing so is not considered Dash.
Similarly, one may shell peanuts and slide off their thin, papery covering on Shabbat. Although nowadays the vast majority of nuts are shelled in the factory, nevertheless, since nuts are sold in their shells as well, cracking them in order to eat them is still not considered Dash.
Almonds have an outer green hull and an internal hard shell. Generally almonds are sold with the outer hull already removed and the hard shell still intact. One may remove the hard shell in order to eat the almonds. But if the green hulls were left on the almonds, one may not remove them because of Dash (Rema 319:6; MB ad loc. 24). In contrast, one may remove the hull of a single almond and eat it, and then remove the hull from another one and eat it. Since one is shelling and eating only one almond at a time, this is not the normal, commercial way that Dash is performed, but rather derekh akhila (Kalkelet Shabbat).
. According to Rif, Rambam, Rosh, and Ramban, the permission granted in Beitza 13b to rub wheat stalks manually with a shinui refers to Shabbat, while on Yom Tov one may do so even without a shinui. According to Rashi and Tosafot, the permission to rub the stalks by hand with a shinui refers to Yom Tov, while on Shabbat even with a shinui one would be transgressing a rabbinic prohibition. The halakha is in accordance with those who are lenient, since this is the opinion of most poskim. In addition, this is a case of doubt about a rabbinic mitzva, where we are generally lenient. This is also the ruling of SA 319:6. See Rema 510:1.. Shevet Ha-Levi 1:81 is stringent regarding shelling multiple almonds. Menuĥat Ahava 2:6:3 rules similarly regarding almonds and peanuts. SSK ch. 3 n. 104 is lenient regarding shelling multiple almonds in order to eat them, maintaining that since they are generally sold with the hard shells, the removal of the latter is not derekh melakha but derekh akhila. Az Nidberu 12:7 rules similarly regarding peanuts. Since this is a case of doubt about a rabbinic law (since the peeling is done by hand and not with a utensil), the halakha follows those who are lenient, as does the custom here. One may also remove a peanut’s thin, reddish-brown peel. This is the approach of Or Le-Tziyon 2:31:7 and Yalkut Yosef 319:59. One who wishes to act in accordance with all the opinions should shell and eat the almonds and peanuts one at a time. This is because according to Tzemaĥ Tzedek and Kalkelet Shabbat, when done this way there is no prohibition of Dash at all. See Menuĥat Ahava, n. 16. In any situation where one is in doubt about whether removing a shell raises a problem of Dash, it is preferable to avoid the problem by shelling the units of food one by one and eating them. Similarly, when shelling with a shinui, such as with one’s fingertips, there is no prohibition of Dash.