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The choice of materials for food applications is
critical if we are not to poison someone.
As Masters of
Metals- ahem, machinists- many of us feel that there is no need to buy the
expensive store bought items that we can easily cobble together from a few
common on hand materials.
(Personally the
use of the galvanized garbage can doesn't bother me nearly as much as the
possibility of galvanized wire cages being used for grates for fire or grills
for food contact.)
I'll pass along
the University of Maryland's word of
caution to avoid zinc for food contact and high temperature
(fire) applications.
While the
temperatures involved in smoking foods are far lower than those encountered in
welding and metal flame cutting, the minimal risk of zinc is unnecessary.
The use of
galvanized (zinc containing) steel grates - from old refrigerators or
chicken cages or galvanized fencing should be avoided for applications
actually touching food.
So if you are determined to make your own Rube Goldberg food preparation equipment what
metal should you use?
(Stainless steel
baby! Use Stainless!)
National
Sanitation Foundation (NSF) recommends stainless steel:
NSF 51 Sect 7.1 Stainless steel
7.1.1
Stainless steel
used in food equipment shall be of a type in the AISI 200 series, AISI 300
series, or AISI 400 series.
7.1.2
When used in a
food zone, stainless steel shall have a minimum chromium content of 16%.
Stainless steel
with a chromium content of less than 16% may be used for cutlery, blades, and
similar applications requiring a sharp edge, provided the alloy has been
hardened or tempered by an appropriate post-weld heat treatment process.
We don't know why
NSF thinks that the heat treat needed is a post weld heat
treatment, (who is welding blades?) The blades may be quench and tempered to
develop microstructure and toughness… but we'll still trust their opinion
about the safety aspects.
Now who has a great recipe for a dry rub…
NSF 51 pdf
Garbage can smoker
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Re: Approved Stainless Steels for Your Rube Goldberg Kitchen Project
