More Discussions for this daf
1. Borer 2. Rava and Abaye 3. Tosofos DH v'Chi Mutar
4. Borer According to Rashi 5. Maga B'Tumas Meis vs. Maga B'Mais 6. Listing Ofeh insted of Bishul
7. Why can't we asked Rav Chisda's question on Abaye? 8. Why aren't temporary knots prohibited? 9. Kotesh
10. Prohibition Of Medicine Use 11. The Shi'ur of Chalah for practical purposes 12. משכן מקדש
13. בורר ואוכל בורר ומניח 14. הבורר תורמוסים מתוך פסולת 15. האי מאן דשדא סיכתא לאתונא
16. האי מאן דעבד חלתא

Pesach Feldman asked:

On Shabbos 76B regarding the requirement to separate Chalah, you write (Background to the Daf) that we separate Chalah with a Berachah only for dough made from the volume of 43.2 Beitzim of flour (about 10 1/2 cups or 2.48 liters). An amount about half that much requires Chalah to be separated without a Berachah.

I am curious about your calculation. I think that R. Chayim Na'eh considers a Beitzah to be about 2 fluid ounces or 57 milliliters, so 43.2 eggs comes out to your Shi'ur with a Berachah, the Chazon Ish Shiur would be about 70% bigger. My Sidur and Rav say to separate on 1.2 Kilos without a Berachah, and 2.25 Kilos with a Berachah ­ I have measured several times, always getting about 7 cups per kilo, we don't make a Berachah on less than 16 cups!

My questions therefore are as follows:

1. Why separate for half that amount without a Berachah? We should not separate for less than that amount at all!

2. Why do we give a Shiur in weight and not volume? The Shiur given by Chazal is in volume!

Thank you,

Pesach Feldman, Jerusalem, Israel

The Kollel replies:

A kilo of flour is a measure of weight, not volume. When it comes to water, we can use the kilogram as a measure of volume, since by definition a gram is the weight of 1 milliliter of water; thus a liter weights 1 kilogram.

Flour is lighter than water so a kilogram of flour has a much greater volume. The Rishonim say it is 1/3 lighter; today's flour seems to be half the weight of water. This makes the R' Chaim Na'eh shiur 1.25 kilo and the Chazon Ish shiur about 2.2 kilo of flour.

Be well,

Mordecai Kornfeld