Metal
in Coffee - Yes
it happens from time to time, fortunately not that often, but it only needs to
get into someone’s coffee and they have the possibility of grinder damage.
Sweeping with a metal detector is one option, but many are set to discriminate
out long thin objects like nails!! There are a plethora of smaller hand held
sensors on e-bay, but made in china and probably not that effective on very
small metal objects. The real hand held security scanners are quite expensive,
but again probably won't help you detect pins and staples within the
coffee.
In
general, most of the metal in coffee is going to be magnetic, your are less
likely to find copper, aluminium or stainless steel. In the case of Copper and
Aluminium, being quite soft possibly won't cause as much (if any) grinder burr
damage as Stainless Steel. So weeding out all the magnetic objects, is going to
solve a big part of any potential problem.
I
had considered Ferritic Magnets, cheap, cheerful and a nice big hand sized block
is around £8-9, this large magnet could be used to sweep the coffee, but does
rely on remembering to do it and also doing it properly. I decided that this was
all a bit too much hassle and prone to error. Instead
I opted for small neodymium magnetsthese
are extremely powerful for their size and if the correct type are sourced, fit
nicely in the Cooling Tray exit chute of the Toper Cafemino. This means your
beans are automatically magnetically swept each time you empty the cooling tray
into a container, you can never forget!
I
sourced the magnets from http://www.uk-magnet.com and went for the neodymium
rectangular block magnets, part number EP647, 10 magnets measuring 25mm x 10mm x
3mm, cost £9.05 inc delivery. These fit very nicely in the
roaster exit chute as you can see from the pictures, and because they are
magnetic, they just stick there under their own magnetism. They are also on so
strongly, they won't ever fall off
It is worth mentioning that you should let your coffee cool before allowing
it out of the chute to prevent heat affecting the magnets
I did post about this article on TMC hoping to get some sensible feedback and
information, but unfortunately nothing much came from it. Only one silly comment
that metal doesn't even figure in the list of defects for coffee and that good
coffee won't have metal in it (and further comments to imply that I wasn't using
good coffee). I assure you that any coffee can have metal in it, from a simple
staple (if they have been stapling anything to the bag), to small iron nails,
often used to hold together wooden frames and implements around the drying area
or during storage and bagging..
My view is that out of respect for your customers you should do everything
reasonable to ensure a clean product. Even if the metal is a once in a blue moon
occurence....because it's not your grinder is it!
