[Avodah] re Halachic guidlines for kashrut

[Micha Berger]

On Sat, Dec 03, 2011 at 10:51:57PM -0500, Harry Weiss wrote:
: On minor quip, what Reb Moshe ztl allowed was peanut oil, with Mei
: Kitniyot being an additional leniency.

I wonder, given a similar rationale to the one RHW suggests, why we
avoid corn syrup -- liquid from a source that we couldn't have been
using when the minhag started.

But that's not that RMF actually wrote about peanuts. From
<http://www.ok.org/Content.asp?ID=172> R' Berel Levy of OK Labs,
a translation of IM OC 3:63:
    Concerning peanuts, which were called stashkes in Europe --
    they have been accepted as being permitted on Pesach and are not
    considered kitniyos (legumes that are forbidden on Pesach) because
    all the reasons for the prohibition of kitniyos do not apply to
    peanuts. Peanuts are not sown in fields (with grain), and even if
    they were there is no fear that grain would be mixed together with
    the peanuts; bread is not baked from peanuts; and generally speaking
    though they are vegetables they have the appearance of nuts rather
    than kitniyos. And even though I have heard that in some places they
    were considered kitniyos, peanuts should not be forbidden in places
    where it is not known for certain what the custom had been in their
    city, because, with reference to kitniyos, when in doubt one should
    be lenient.

    Therefore you may give certification for peanuts and the oil
    derived from them, and they will be permissible to the majority of
    persons. Those who know for certain that the custom of their city
    was not to eat peanuts on Passover should not eat them; others are
    permitted to eat them.

Not specifically the oil; no need for a second tzad heter. However,
RMF acknowledged that some (minority) forms of the minhag of qitniyos
do prohibit peanuts.

There was a long period in US O history when peanut oil was the oil most
homes used for Pesach.

Tir'u baTov!
-Micha

-- 
Micha Berger             One doesn't learn mussar to be a tzaddik,
micha at aishdas.org        but to become a tzaddik.
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