May I wrap the challa on the urn with a towel?
Many are accustomed
to place challa above the urn, on Shabbos or before and indeed there
is nothing wrong in doing so. As explained in previous shiurim,
challa is a baked solid and may be reheated above yad soledes bo
in the permitted manner, i.e. above an urn or other container,
on the hotplate or blech.
The problem is that
one may not do hatmana, even before Shabbos.
What is hatmana?
Enveloping a food
item with towels, sheets or cloth near or on a heat source is
hatmana that adds heat.
Although the wrappings do not add heat, the entire arrangement does,
as we view the wrappings together with the heat source as a method
that adds heat.
But I am wrapping the challa before
prohibited this even before Shabbos. This does not mean that you may
not place a towel over challos; it means that you may not do
hatmana. Because the normal manner to contain heat is by
completely enveloping the food item or container, wrapping a towel
in a way that the challa is not totally enveloped is
permitted. Leaving a noticeable section uncovered is not hatmana.
I would suggest
that you leave the entire end of the challa unwrapped.
Does the same halacha apply to containers
on the blech or hotplate?
Yes it does. One
may not use a towel to completely envelope any single container. If
the towel is placed so that a noticeable section of the container
remains uncovered it is not hatmana.
Consequently one may place a towel over a couple of containers on a
heat source because the towel only wraps a portion of each container
and not an entire container. It is also accepted that surrounding on
all sides except the lid is not hatmana.
What about an urn surrounded by an
This would seem to
be a perfect case of prohibited hatmana. The sleeve is
intended to ‘add’ heat to the electric urn and since it almost
completely surrounds it. It is hatmana that may not be done
even before Shabbos.
Which hatmana is permitted?
Shabbos in the absence of a heat source: I have seen people
remove the soup from the heat source close to Shabbos for the Friday
night meal and store it in feather downs. This is perfect hatmana,
as the down completely envelops the container of soup. However,
since this is performed before Shabbos and there is no heat source
it is permitted. This is different to the challa on the urn that is
close to a heat source.
And on Shabbos?
Such wrapping, even
in the absence of a heat source, is prohibited on Shabbos.
For example, the cholent container was removed from the heat
source. It then became apparent that the d’var torah was
taking longer than expected. The container had been placed on the
counter without the intention of returning and thus cannot be
returned back to the heat source. To save the day, the host then
wished to wrap the container in a towel to conserve heat, until
ready for serving. This is forbidden, being a classical case of
hatmana. The container of cholent may however be
partially wrapped in a way that a noticeable section of the
container is exposed.
May one fill a thermos with water from the
urn on Shabbos?
The point is that
on the one hand a thermos bottle contains and preserves heat because
of the wrapping of the inner container, which would appear to be
hatmana. On the other hand it is a single k’li and
hatmana is usually the wrapping of a k’li with other
items. For the same reason food wrapped by the container itself is
permitted. Common custom is to use the thermos bottle on Shabbos for
A) It is a single k’li. B) The prohibition of hatmana
only applies to the k’li that is or was on the heat source.
If its contents are transferred to another k’li, it may be
May I place a pulka inside the cholent
container to heat it up?
cholent container is off the fire, because you would be doing
prohibited chazora by ‘returning’ the pulka to the
heat source. The halachic issue is whether hatmana
applies to food within food.
The answer is that
hatmana only applies to food in a container and not directly
Accordingly the pulka may be put inside the cholent off the
An egg in its shell might be subject to the constraints of
hatmana, because it is viewed as food within a k’li.
One may therefore not place a cooked egg inside a cholent to reheat
unless a noticeable portion of the egg emerges from the cholent sea.