Intro: While the siman on kneading on Yom Tov is relatively long in the Shulchan Aruch (9 paragraphs), Rav S. B. Cohen summarized its halachos in just 1½ pages! We will follow the Rav’s lead and present an abridged summary of the halachos of kneading as well, even incorporating excerpts from his sefer, The Laws of Yom Tov.
“Kneading. One of the thirty-nine ‘avos melachos’ (main categories of forbidden labors on Shabbos) is ‘lisha’/kneading. Kneading is defined as binding together small particles (e.g. flour), by means of a binding agent (e.g. water), to form one mass. While the most common case of kneading is making dough, there are many other examples of this melacha such as mixing baby cereal with milk to form a porridge.” (The Laws of Yom Tov by Rav Simcha Bunim Cohen, Chap. 10, pp. 83)
Kneading on Yom Tov. (To quote MBY Archives 495 – section 1): “In practice, we follow the Rama’s opinion, and consequently, the only melachos which are permitted are those which must be done on the day of Yom Tov itself, or else the taste or freshness of the food will be compromised. That still leaves quite a few melachos that are permitted, notwithstanding the modern methods of refrigeration and storage that we have today. Thus, slaughtering (‘shochait’), cooking (‘bishul’), kneading (‘losh’) and baking (‘ofeh’) fresh breads and cakes are all permitted on Yom Tov! [Note: This stringency of the Rama is a Rabbinic fence, intended to get people to work less and relax more on Yom Tov! If a person did not do those melachos that he could/should have before Yom Tov (i.e. the ones which Mechaber permits and Rama prohibits, e.g. stewing fruit, baking hard noodles etc.), he may do them on Yom Tov with a ‘shinui’ (i.e. in an unusual manner) and, under extenuating circumstances, even in the normal manner.”
On the question of whether or not kneading on Yom Tov ever requires a ‘shinui’, Rav Cohen writes (Ibid.): “However, in most cases, a food mixture loses some flavor if prepared a day in advance, and therefore, one may do the kneading on Yom Tov in the usual fashion.” Included in the examples of kneading one is permitted to do on Yom Tov in the usual manner, Rav Cohen lists: dough, instant potatoes, baby cereal (of any consistency) and chopped egg or tuna with oil or mayonnaise. [Ed. For an appreciation of how the halachos of ‘lisha’ on Yom Tov are more lenient than those of ‘lisha’ on Shabbos, I invite you to review your MBY notes of MBY 321:13-16 Halachos related to food preparation (parts 4 and 5). Holler if you would like me to send them to you!]