For the source text click/tap here: Beitzah 29
To download, click/tap here: PDF
Because we are able to prepare food on Yom Tov, it is possible for people to find themselves in a situation in which they discover that essential ingredients for the meal are missing. Obviously they can go to their neighbors, borrow raw ingredients, and return them after Yom Tov is over. The last few Mishnayot in our perek relate to such transactions.
In general, it is prohibited to measure on Yom Tov, just as it is prohibited to measure on Shabbos. Thus, one may not measure out how much flour, sugar, or oil to use in a recipe (Shulchan Aruch Orach Chayim 506:1). However, one may approximate how much flour, oil, or sugar is needed. It is permitted to use a measuring cup, as long as one does not fill the cup exactly to its measuring points (Mishnah Berurah 506:3).
We examine the science behind measuring food and calories.