[Avodah] K'zayis as weight not volume?

[Zev Sero]

R Davidovich wrote:
> I recently read a teshuva by R'Ovadia Yosef (Yechaveh Daat 1: 16) that 
> gives the measurement for the k'zayis as a weight, not volume.  Instead 
> of saying that the k'zayis is 28cc, which comes out to about  1/6 of a 
> hand-matza according to Rabbi Heinemann's water-displacing  tests, ROY 
> says that  it is 28 grams, which is the approximately the weight of half 
> a hand-matza.  (With standard issue hand matza, you get about 8 matzos a 
> pound, one slice is two ounces, or 56 grams.)

How did R Heinemann do these tests?  AFAIK the halachic standard is
to assume that bread and matzah have approximately the same density
as water, so that 1 ml weighs about 1 g.  See Shiurei Torah chapter 1,
footnote 33; chapter 2, para 1; and siman 3, footnotes 17 and 18. 

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Zev Sero               Something has gone seriously awry with this Court's
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