Hilchos Berachos part VII

Amount necessary for b’racha acharona

Although one recites a b’racha rishona on even a minute amount of food, [1] one must eat a certain amount within a certain time frame to recite a b’racha acharona, whether it is birkas hamazon, al hamichya (me’ein 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 b’racha acharona is a k’zayis, the size of an olive. Since the possuk says åàëìú åùáòú åáøëú and eating in the Torah is a k’zayis, a b’racha acharona may only be recited when a k’zayis is eaten. And even though this possuk refers to eating bread, Chazal instituted all after b’rachos in this fashion. [3]

How much is a k’zayis?

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

Rav Chaim Na’eh - 27cc or 1oz

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

Rav Moshe Feinstein ztz”l - 31cc or 1.1 oz. [6]

What is the halacha?

Contemporary poskim rule [7] that based on custom, one will recite a b’racha acharona after consuming a k’zayis according to Rav Chaim Na’eh. [8]

There are those that follow the stringency of the Chazon Ish and will only recite a b’racha 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 b’racha, rather consume at least 50cc and recite a b’racha acharona.

What is the time frame?

The time frame is something called ëãé àëéìú ôøñ, which according to R’ Chaim Na’eh [9] is 4 minutes and according to Rav Moshe Feinstein it is less than 3 minutes. [10]

This means that one who ate a k’zayis within this time frame must recite a b’racha acharona.

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

Do the same rules hold for liquids?

Volume

One who consumes a øáéòéú äìåâ (a quarter of a log) will recite a b’racha acharona. Here too we find a machlokes, where

Rav Chaim Na’eh - 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 ëãé ùéòåø ùúééú øáéòéú. 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 one’s mouth and one downs the revi’is without removing the cup from one’s lips, and “two swallows” mean that the drink was consumed in two quick sessions, while removing the cup once from one’s lip. [13]

Many others hold that liquids share the same time frame as foods, i.e. ëãé àéìú ôøñ. [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 ëãé ùéòåø ùúééú øáéòéú, one will not recite a b’racha 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 b’racha acharona if the beverage was consumed within 4 minutes. [16]

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