|The Guide To Halachic Food Measurements
Rabbi Dovid Heber, Star-K Kashrus Administrator
Conscientious observance of kashrus goes beyond the identification of kosher symbols on your supermarket shelf and the separation of meat and dairy foods and utensils in your kitchen. There are many food related halachos, in addition to those involving preparation and serving. Amongst them are the halachos of shiurim, measurements. They encompass a wide range of issues relevant to food consumption, and have important halachic ramifications.
How much must one eat to recite a bracha acharona, the blessing after eating? How much bread must one eat to be obligated in netilas yadayim, hand washing, or to fulfill one's obligation of seudas Shabbos? The answers to these and other questions relating to shiurim have been addressed by gedolei haposkim, but are often not well known. There are many age old opinions regarding shiurim and it is often difficult to translate the measurements of Chazal into today's terms.
Additionally, though Chazal chose to describe measurements in terms of commonly used items or foods such as a kizayis (olive) and a kibeitzah (egg), the size of a standard size egg 1800 years ago may have been larger than today's egg. Similarly, there are many varieties of olives, and we are uncertain which one is used for the kizayis measure. Therefore, shiurim must be defined in contemporary terms. This article will attempt to clarify the halachic parameters of food related measurements.1
As with all halacha, for a definitive psak one must consult his Rav. The halachic rulings regarding shiurim by Rabbi Moshe Heinemann, shlita, Rabbinic Administrator of Star-K, are as follows:
I. Kizayis Measurement2 - 1.27 fl. oz. (38 ml) - If one eats a kizayis3 of bread, he must recite birchas hamazon.4 Similarly, if one eats a kizayis of any other food, a bracha acharona must be recited.
Our testing indicates that this is the approximate size of a golf ball (40 ml) or a roll of quarters (37 ml). Approximately seven Manischewitz Tam Tams comprise a kizayis. Therefore, if one consumes this amount, an al hamichya blessing is required. A complete graham cracker (both halves) has a volume of approximately 27 ml. Therefore, if one eats only one graham cracker, a bracha acharona is not recited. An additional one half must be eaten in order to say the bracha acharona. A bracha rishona is required even for any amount less than a kizayis from which one is neheneh (derives benefit).
When eating bread or cake, one should calculate in his mind whether it has a volume of 38 ml (e.g. whether it has the volume of a golf ball). It is impossible to state how many slices of bread equal a kizayis, as bakeries and bread companies bake bread in many different sizes.
On the first two nights of Pesach one should eat two kizaysim of matzah at motzi matzah.5 This is equivalent to approximately one half of a standard size machine matzah or one third of an average hand matzah. If eating this amount is too difficult, one may eat one kizayis - i.e. one quarter of a machine matzah or one sixth of an average size hand matzah. A kizayis is also the amount of marror one must eat to fulfill that mitzvah.6
II. Kibeitzah Measurement - 2 kizaysim, 2.53 fl. oz. (75 ml) - The kibeitzah7 measurement is relevant to numerous halachos throughout the year. It is equivalent to approximately two golf balls. When washing before eating bread, one recites the bracha of al nitilas yadayim only if one intends to eat a kibeitzah of bread.8
It is preferable for one to eat more than a kibeitzah of bread at each of the three Shabbos meals and two Yom Tov meals. Similarly, on the first two nights of Sukkos, ideally one should eat this amount of bread9 in the sukkah.10 During the rest of Sukkos, if one eats more than a kibeitzah of bread or cake, a bracha of leishev basukka is recited.
III. Kidei Achilas Pras Time Measurement - Volume is not the only factor in determining whether a bracha acharona is recited. Chazal dictate that a bracha acharona is only recited if one eats a kizayis in the amount of time known as kidei achilas pras.11 This means, to recite a bracha acharona, one should eat a kizayis ideally within two minutes.12 For example, if one eats bread, one should consume a kizayis within any two minute span during the meal to recite birchas hamazon.13
To fulfill mitzvos requiring a kizayis the food must be eaten within the kidei achilas pras time period. For example, on the first two nights of Pesach one should eat a kizayis of matzah within a two minute period.
IV. Revi'is - The "classic" measurement of liquids is a revi'is.14 The Chofetz Chaim15 was of the opinion that this is 3.8 fl. oz. (112 ml). In order to recite a bracha acharona on any beverage, one must drink a revi'is.16 Similarly, the cups used for Kiddush, Havdalah and at the Seder on Pesach night for the four kosos, must hold a revi’is.
The standard measurement of a cup (as found in recipes or on measuring cups) is 8 fl. oz. Therefore, a revi'is is approximately one half of a cup. Four plastic "shnapps cups" that state on the bottom "1 fl. oz. - 29 ml" are also approximately a revi'is. As a point of reference, a can of soda is 12 oz. - slightly more than three times the revi'is measure.
Although a Kiddush cup must hold a revi’is, the amount of wine that one who recites Kiddush needs to drink is a m’lo lugmav, one cheekful.17 This amount is different for each person. In general, a m’lo lugmav for adults ranges between 1.55 fl. oz. and 2 fl. oz. The way each person calculates his own m’lo lugmav will be addressed in section VI-B.
Similarly, a m’lo lugmav must be drunk for Havdalah. At the Pesach Seder, for each of the four cups one must drink at least a rov revi’is (2 fl. oz.) or a m’lo lugmav whichever is larger.18
V. Halachic Time Frame When Drinking Beverages - As with eating, Chazal dictate that a bracha acharona is only recited if one drinks a revi’is within a stipulated amount of time. Unlike food where this time is kidei achilas pras, the “time limit” for beverages is “kidei shtiyas revi’is.”19 This means that to recite a bracha acharona on wine or any other beverage, one must drink 3.8 fl. oz. within a thirty second span.20
It is difficult to drink a hot beverage such as coffee within the thirty second time span, as hot drinks are generally sipped slowly. If 3.8 fl. oz. are not consumed during any thirty second span, a bracha acharona is not recited. The same applies to hot soup. Although a hot beverage is initially too hot to drink in the halachic time limit for drinking, eventually, if it cools and 3.8 fl. oz. are drunk within 30 seconds, a bracha acharona is required.21
VI. Cholim - Shiurim For One Who Is Ill On Yom Kippur
A. Food - Someone whose life may be in danger by fasting on Yom Kippur is obligated to eat. Not all cholim who are obligated to eat on Yom Kippur have the same halachic dispensation. There are cholim (who may be in danger) whose illness only warrants minimal eating or drinking. Minimal consumption is termed pachos mi’keshiur - below the minimal portion that qualifies for halachic22 eating and/or drinking. What is pachos mi’keshiur for eating and drinking? On Yom Kippur the pachos mi’keshiur requirement is the volume of food that is less than a koseves hagasa, a type of large date. The volumetric measurement of a koseves hagasa23 is more than 1.5 fl. oz. (44 ml). Therefore, one who is ill (as above) may eat 1.5 fl. oz. (which is less than a koseves hagasah) of food every nine minutes. A practical way for the patient to do this is as follows: Fill 11/2 "shnapps cups" that are marked "1 oz. - 29 ml" with compacted24 bread, crackers or cereal, and consume that amount every nine minutes.
Note: If it is determined that this amount is insufficient and one's life may still be in danger, the patient must eat as much as necessary, even if it is more than the shiur of volume and less time than kidei achilas pras.
B. Beverages on Yom Kippur - The minimal volume for beverages that qualifies for pachos mi’keshiur (minimal consumption by a choleh whose life may be in danger) is less than a m’lo lugmav, a cheekful of liquid. Unlike food, the shiur of liquids differs with each individual's capacity to hold liquid in his or her mouth. The larger the mouth, the larger the m’lo lugmav. Conversely, the smaller the mouth, the smaller the m’lo lugmav. For purposes of drinking on Yom Kippur we say an average adult has a m’lo lugmav25 that is larger than 1.5 fl. oz. (44 ml). A teenager may have a smaller m’lo lugmav. One can ascertain his or her personal m’lo lugmav by filling his mouth completely with water, expelling the water into a measuring cup and dividing the amount in half.26 This number is the amount held by one cheek - a m’lo lugmav.27 Pachos mi'keshiur is slightly less than this amount. This "test" should preferably be conducted before Yom Kippur.
How infrequently should a person who is forced to drink on Yom Kippur take a drink so that his intake does not qualify for halachic drinking?28 Ideally, less than a m’lo lugmav may be consumed and then repeated up to every seven minutes. If this amount of liquid is insufficient for the patient, one may drink this amount of liquid every two minutes.
Note: If it is determined that this amount is insufficient and one's life may still be in danger, the patient must drink as much as necessary, even if it is more than the shiur of volume and less than the shiur of time.
On Yom Kippur, the pachos mi’keshiur amounts of food and drink are independent of each other. This means the two shiurim do not combine and one can simultaneously eat and drink a pachos mi’keshiur of both. The waiting times are also calculated independently.29
If one must eat on Yom Kippur, the following sample schedule of eating pachos mi’keshiur may be implemented: Eat and drink at 8:00 a.m., drink - 8:07, eat - 8:09, drink - 8:14, eat - 8:18, drink - 8:21, eat - 8:27, drink - 8:28, drink - 8:35, eat - 8:36, etc. This schedule is for someone who wishes to eat as much as possible pachos mi’keshiur30 in the shortest amount of time. Obviously, a choleh may eat and/or drink pachos mi’keshiur less frequently (e.g. eat and drink pachos mi’keshiur at 8:00 a.m., then eat and drink again pachos mi’keshiur at 8:15 a.m., etc.). If possible, the decision whether one may eat or must eat - pachos mi’keshiur or more than the shiur - should be discussed with a competent halachic authority before Yom Kippur.
VII. Hafrashas Challah - Min haTorah, the amount of flour one must knead to be obligated in hafrashas Challah is an “asiris ha’aifa.” This is equivalent to the volume of 431/5 eggs.31 Regarding hafrashas Challah, the exact volume of this shiur is in doubt.32 L’halacha, one should be mafrish Challah when kneading 2.6 lbs. of flour, which on average is equivalent to 82/3 cups of flour.33 However, a bracha is not recited for this amount. If one kneads a smaller amount of flour, one is not mafrish Challah.34
There are two customs as to the amount that must be kneaded to require a bracha. Some individuals recite a bracha when kneading 3.675 lbs. or more of flour (on average, 121/4 cups).35 Many only recite a bracha when kneading 4.95 lbs. of flour (i.e. almost the entire contents of a 5 lb. bag of flour on average, 161/2 cups of flour).36 Individuals should follow their family custom.37
Whether we are gathered at the Shabbos table, celebrating and preparing for our beautiful Yomim Tovim, or just enjoying a midnight snack, shiurim play a vital role. By understanding and knowing them, we can measure up to the task of fulfilling these mitzvos L'shem U'ltifares.
The author wishes to thank Dr. Yossi Scheller and Mrs. Paysach Freedman for their assistance in the preparation of this article.
1. Note: It is important to emphasize that shiurim are measured in terms of volume, not weight. For example, a kizayis of sponge cake will volumetrically equal a kizayis of potato kugel, yet the weight of the potato kugel will exceed the weight of the sponge cake.