It seems someone got a stainless-steel bar for Christmas, which serves
to remove garlic and onion odors from the hands after chopping them. I
was curious if anyone here could describe how this works.
Spam-block in use. Remove the third letter of the alphabet from my username to reply.
Transition metal-catalyzed oxidation of low valent sulfur compounds.
A little hydrogen peroxide or dilute bleach will also do it. (Get a
garlic press and do it right.)
(Toxic URL! Unsafe for children and most mammals)
"Quis custodiet ipsos custodes?" The Net!
First tell us if it really works, not what it says on the box.
"Uncle Al" <Uncl...@hate.spam.net> wrote in message
>garlic press and do it right.)
I tried this and not only did it not remove the garlic smell ... it really hurt
my hand while i squeezed it ...
The stainless rod works much better ...
In the Village ....
I am not a number ... I am a free man !!!!
>> Hi! Sorry for not lurking before posting, but there was a question
>> raised on another group, and I thought you'd be the folks to answer
>> It seems someone got a stainless-steel bar for Christmas, which serves
>> to remove garlic and onion odors from the hands after chopping them. I
>> was curious if anyone here could describe how this works.
>Transition metal-catalyzed oxidation of low valent sulfur compounds.
>A little hydrogen peroxide or dilute bleach will also do it. (Get a
>garlic press and do it right.)
Sure does, somewhere I have an old International Nickel article on
such garlic odour removing properties of stainless steels, which has
apparently been known amongst French chefs ( surprise! ) for many years.
Stainless steels are effectively passivated by a strongly adsorbed layer
of oxygen. Sulphides ( and some other species, such as selenides ) are
even more strongly adsorbed, and destroy the passivity by displacement
of the adsorbed oxygen. The washing of hands under running water with the
bar apparently also facilitates rebuilding the oxide layer.
: (Get a garlic press and do it right.)
Thus adding cooking to the list of subjects on which Uncle Al refuses to
let his ignorance stop him from giving advice. . .
Richard Schultz sch...@mail.biu.ac.il
Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel
Opinions expressed are mine alone, and not those of Bar-Ilan University
"Logic is a wreath of pretty flowers which smell bad."
Though I love science, my interests tend more towards astronomy and
evolutionary processes. I'm afraid I never got the chemistry education
I would have liked, though I understand the (bare) basics. I think I
get the gist of your post, but was wondering if you'd be kind enough
to dumb it down a little for me.
>On Mon, 31 Dec 2001 04:33:11 GMT, B.Ham...@irl.cri.nz (Bruce
>>Sure does, somewhere I have an old International Nickel article on
>>such garlic odour removing properties of stainless steels, which has
>>apparently been known amongst French chefs ( surprise! ) for many years.
I haven't time to hunt through the basement for the article, so some
of the following relies on my fragile memory, and may be wrong..
>>Stainless steels are effectively passivated by a strongly adsorbed layer
>>of oxygen. Sulphides ( and some other species, such as selenides ) are
>>even more strongly adsorbed, and destroy the passivity by displacement
>>of the adsorbed oxygen. The washing of hands under running water with the
>>bar apparently also facilitates rebuilding the oxide layer.
>wondering if you'd be kind enough to dumb it down a little for me.
The reason that stainless steels are corrosion resistant, even though
they consist mainly of iron, is because they contain a minimum of 12%
chromium, usually along with some other metals.
Ordinary iron and steel alloys rust quickly because atomic iron is much
smaller than oxides formed by interacting with atmospheric oxygen and/or
oxygen dissolved in water. The oxides formed during rusting create a loose
layer that flakes away, exposing fresh metal to the corrosion.
Chromium, along with other metals ( such as nickel ), are added to
stainless steel alloys to help improve physical propeties and corrosion
resistance. The chromium in the stainless steel combines with oxygen,
forming a very thin passive film of chromium-containing oxides.
The sizes of chromium atoms and their oxides are similar, so they bind
together on the surface of the metal, producing a thin oxide layer only
a few atoms thick. If the surface is rubbed or damaged and the passive
film is broken in air or water, more chromium oxides will immediately form
and recover the exposed metal substrate surface, protecting it from
further oxidative corrosion. Note that the oxide film is not physically
strong, it just forms rapidly, and weakly adheres to the alloy, thus
protecting the metal below from further corrosion. It can be disrupted
and displaced easily by abrasion, so many common stainless steels aren't
suitable for corrosive situations where the surface is continually swept,
and special alloys, with other elements are used..
The passive film requires oxygen to self-repair, so stainless steels can
have poor corrosion resistance in situations where there is limited oxygen
or other elements or species will compete with the oxygen. The smelly
active sulphur species in garlic and onions; the volatile selenides in
garlic, cabagge, and broccili; and also the chlorides in salty water will
all attack and destroy the passive film of most stainless steels more
quickly than the film can be repaired in a low oxygen environment.
Some of the smelly compounds will bind to your hands ( onto proteins,
lipids etc ) and will become non-volatile ( non-smelly ), but the number
of binding sites is limited, hence any excess of smellies results in
By binding to the metals in the stainless steel bar, the unbound smelly
compounds on the surface your hands are transformed into non-volatile
( and thus non-smelly) compounds and complexes on the surface of the
stainless. The new surface layer, which is weakly adhering and fragile,
will be continuously abraded off by the active rubbing of the bar and
replaced by oxides using oxygen from air or water.
For many stainless steel items, especially those in contact with chemicals
or water, passivating metal finishing processes are applied ( such as
treatment with nitric acid ) when fabrication is complete. This ensures
they start life with a good, thick layer of oxide. Otherwise corrosion
may start in any crevices, scratches, or heat-affected areas ( welding ),
and unprotective deposits ( eg smutty black sulphur layers ) may form in
low oxygen environments, such as water.
I hope the above is more understandable, and addresses your questions.
"Bruce Hamilton" <B.Ham...@irl.cri.nz> wrote in message
You've made it very clear to me in a way that I understand. Thanks so
much for taking the time to do so...you've taught me something, and I
value anyone for doing that.
Well, maybe yes. There are some purists who
would insist that steel or cast-iron cookware
provides a superior flavor. At this juncture,
you have to deal with the nuances in cookware
care...how you maintain your tools. This is,
of course, a subject best discussed in other,
more appropriate, groups. Chemists traditionally
eat shit without a qualm, having destroyed their
senses with long periods of exposure to chemicals
that would etch the eye-balls of a virgin within
a few seconds.
Mark (I can't believe I said that! Is 2002
_really_ a war year? Bush must be nuts!)
"Mark Tarka" <ma...@in-tch.com> wrote in message
Cast iron cookware is often considered to contribute off flavours,
and carbon steel cookware is usually coated with vitreous enamel
( which chips easily and decreases thermal conductivity ) to prevent
rusting and corrosion.
The main advantages of iron is the improved thermal conductivity,
when compared to stainless, although there is a lot of stainless
steel cookware with copper and aluminum bases. When cookware is
being purchased, I suspect that thermal conductivity is of far
greater significance than potential slight flavour changes due
to contact with the cookware surface, particularly given the
surface area to volume ratios of most cookware.
>Come to think about it, I have seen iron frying pans and
>woks. Also, there are tinned copper pans as well.
Chefs tend to prefer copper, usually tinned or stainless steel
lined, mainly because the heat transfer is so good that heat input
to food can be rapidly and accurately controlled. Aluminium pots
can be corroded in dishwashers and are also attacked by some foods,
and so are less favoured, even with good conductivity.
That's very well, but the garlic odor compounds diffuse into the skin,
and only slowly diffuse out. There's nothing in the stainless bar that
can make them diffuse out faster. And insofar as they do diffuse out,
you can wash them away with soap and water. The only way the stainless
bar might improve the situation is if it were coarsely ground, so that
rubbing it abraded away the surface layers of the skin -- but to achieve
that effect, an even better way would be to wash one's hands with
(Yes, I just tried it: I rubbed my palm with garlic, then washed it with
detergent and water (which didn't completely remove the odor), then
rubbed it with a stainless bar under water (which didn't do much to the
Norman Yarvin norman...@snet.net
I assume you used cold water, as warm or hot water are contra-indicated
for removing such smells from skin, as they open pores and drive the
smell deeper. Obviously your brave experiment has validity, but there
does appear to be a valid mechanism ( refer my subsequent post ) however
I've no idea whether the kinetics permit effective smell removal before
people die of old pneumonia or old age..
My recollection of the article was that the bar ( as in a soap
bar, not rod or pub ) surface was coarsely wire brushed, not polished.
The colour picture showed a rough matt surface and, IIRC, the article
specified the alloy used, but I can't recall if the extent and type of
passivation were described. If I haven't thrown the article out, I'll
try and find it over the next week or so.
The bar could be also abrading the skin, as some of the other recommended
treatments ( rubbing with salt before washing with cold water ) possibly
do as well. However a quick check of the WWW indicates that various
stainless steel surfaces are claimed to be effective at cooking sites.
Whilst extensive appearance on the WWW may indicate a popular
Urban Legend, various sites claim stainless steel is effective for
removing garlic and onion smells - with some emphasising that you should
use the bar immediately after handling the garlic to avoid the oil
One post in rec.foods suggests the bars have been tested by Consumer
Reports and claims they were found effective, but no reference is given.
Another site also claims anecdotal evidence of effectiveness.
I wasn't planning on adding it to the FAQ ( only been asked once ) but
would be very interested in any evidence that helps determine whether the
bars ( or other stainless items ) are effective.
>Hi! Sorry for not lurking before posting, but there was a question
>raised on another group, and I thought you'd be the folks to answer
>It seems someone got a stainless-steel bar for Christmas, which serves
>to remove garlic and onion odors from the hands after chopping them.
To clarify, that's after chopping the onion and garlic; not the hands.
I use mechanic's hand cleaner sold in automobile parts stores
to clean my hands of garlic and onion odor.
It entirely removes the odor.