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Weekly Shabbos Halacha Series
Halachos Series on Hilchos Shabbos

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Published by
Pirchei Shoshanim

A Project of
The Shema Yisrael Torah Network

Written by

Rabbi Dovid
Ostroff, shlita


These Halachos were shown by Rabbi Ostroff to
HaGaon HaRav Moshe Sternbuch, shlita



Questions for the Week of Parshas Balak


Hilchos Berachos part VII

Amount necessary for bracha acharona

Although one recites a bracha rishona on even a minute amount of food, [1] one must eat a certain amount within a certain time frame to recite a bracha acharona, whether it is birkas hamazon, al hamichya (meein shalosh) or boreh nefashos. [2]

We need to clarify the amount needed to be eaten; whether food and beverages are the same; the time frame.

What is the required amount?

The required amount of food needed to be eaten to recite a bracha acharona is a kzayis, the size of an olive. Since the possuk says and eating in the Torah is a kzayis, a bracha acharona may only be recited when a kzayis is eaten. And even though this possuk refers to eating bread, Chazal instituted all after brachos in this fashion. [3]

How much is a kzayis?

Many intricacies involve calculating the shiur of a kzayis, which we will spare you of; [4] however, it is known that

Rav Chaim Naeh - 27cc or 1oz

Chazon Ish - 45-50cc or 1.65oz. [5]

Rav Moshe Feinstein ztzl - 31cc or 1.1 oz. [6]

What is the halacha?

Contemporary poskim rule [7] that based on custom, one will recite a bracha acharona after consuming a kzayis according to Rav Chaim Naeh. [8]

There are those that follow the stringency of the Chazon Ish and will only recite a bracha acharona upon consuming 50cc of food.

One who wishes to be stringent should not consume more than 27cc and less than 50cc because it involves a safek bracha, rather consume at least 50cc and recite a bracha acharona.

What is the time frame?

The time frame is something called , which according to R Chaim Naeh [9] is 4 minutes and according to Rav Moshe Feinstein it is less than 3 minutes. [10]

This means that one who ate a kzayis within this time frame must recite a bracha acharona.

If one is in doubt whether one ate a kzayis within 4 minutes or more, one will not recite a bracha acharona, because it is a safeik and when in doubt one does not recite a bracha. [11]

Do the same rules hold for liquids?


One who consumes a (a quarter of a log) will recite a bracha acharona. Here too we find a machlokes, where

Rav Chaim Naeh - 86cc or 2.9oz

Chazon Ish 150cc or 5oz.

Rav Moshe Feinstein 93cc or 3.3oz.

What is the time frame?

According to some opinions, beverages have a different time frame, something called . It is very unclear what this shiur is. Some say that it is according to how people normally drink a beverage, which the Mishna Berura explains to be in two swallows. [12]

Others explain that one swallow means the cup is continuously held to ones mouth and one downs the reviis without removing the cup from ones lips, and two swallows mean that the drink was consumed in two quick sessions, while removing the cup once from ones lip. [13]

Many others hold that liquids share the same time frame as foods, i.e. . [14]

What is the halacha?

The Mishna Berura writes [15] that custom is that if one imbibed a beverage in the time frame longer than , one will not recite a bracha acharona. In effect one would need to consume 86cc (which is not that much) in one or two gulps.

Many others have the custom to recite a bracha acharona if the beverage was consumed within 4 minutes. [16]

[1] MB siman 210:3.

[2] Siman 210:1.

[3] MB siman 210:4.

[4] For more detail see the seforim written on brachos.

[5] The Chazon Ish really held that a kzayis is a third of an egg, which is 17cc, but because of a safeik he preferred one be stringent and consume the large amount before reciting a bracha. See in the , at the end of the sefer.

[6] Hagodas Kol Dodi b, see Beirur Halacha in '.

[7] See the Beirur Halacha ibid citing Rav Shlomo Zalman Auerbach ztzl and HaRav Eliashiv shlita.

[8] See also Biur Halacha 271:13.

[10] " " " .

[11] MB siman 207:4.

[12] Shaar Hatsiun siman 210:11.

[13] See in the name of Kol Dodi in the sefer .

[14] See MB 210:1 citing the Vilna Gaon.

[15] Ibid.

[16] " cites Rav B. Zilber, Rav Eliashiv, Chazon Ish and the Steipler. Rav Sternbuch shlita follows the opinion that holds that one makes a b'racha acharona when consumed within .


Vort on the Parsha

If G-d looks at the future and acts on it in the present, as we see that he told Bil'am that he wants to curse a nation who will perform aliya laregel at the Beis Hamikdash three times a year, then why when Balak took Bil'am to Rosh Hapisga, where B'nei Yisroel would sin, did Hashem not act on that?

The Parshas Derachim (Mishne Lamelech) answers that Hashem looks into the future and acts on it in the present when it is favorable and does not act on it when it is not.

Hashem sees and knows that one will improve and therefore he is protected on account of the beautiful tree that is now only a seed, sometimes rotting in the ground.

Am Yisroel will serve Hashem.


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