"Alan Shutko" > wrote in message
...
> writes:
>
>> Charcoal briquettes sure do have a flavor, the flavor of the coal that
>> is used to make them.
>
> Charcoal is not made from coal.
Real charcoal is not, but charcoal briquettes contain coal. You may find
this of interest.
Charcoal
This interesting description of the charcoal briquette manufacturing process
was posted to another list to which I subscribe. I thought some of you
might find the description of the process and even more, the extra
ingredients incorporated into the briquettes very interesting, in light of
several threads on this list in the past.
Rodney
Recently, I had a chance to tour a BBQ charcoal test lab and thought it
might be of interest to some of you. A friend works for the parent company
that owns this charcoal briquette company and invited me up for a tour. I
have been asked to not use the name of the parent company or the name of the
briquette charcoal maker, but I can tell you that it is the largest supplier
of cooking briquettes in the country and it's name is usually the first one
mentioned when talking about charcoal briquettes.
Their high-volume > manufacturing facilities are located in about 6
locations in North America, but their R&D/test lab is just up the road in
Pleasenton, Cal. I also found out that the barbecue cooking charcoal
industry was started by Henry Ford, who wanted to do something with the
scrap wood, shavings and sawdust byproducts from his automobile
manufacturing plants. The model T used wood spoke wheels, while wood braces
were also used extensively throughout the body. This will also give a hint
as to the name of the briquette company.
Its funny how this lab resembled a large pyro work shop. There were several
55gal drums of various types of charcoal, charcoal grinding machines,
tumblers and mixing bowls. There were also electro-hydraulic presses for
pressing single briquettes and a really neat machine that would mass produce
the briquettes. Some parts of this lab were also dirty, with tools coated
with a fine charcoal dust.
The briquettes can be made from retort produced charcoal and retort produced
low-sulfur coal. Chunky charcoal was passed through a grinder to get the
desired particle size. This ground charcoal looked to have variable mesh
sizes from airfloat to ~10 mesh. There were also some drums of uncarbonized
wood chips, like sawdust, that might be added for a smoky flavor. Burn-rate
stabilizers, like sodium nitrate are used, as are corn starch binders and
limestone, which acts as a burn-rate inhibitor. When these briquettes are
used for pyro effects, it could be a combination of things that give the
longer lasting sparks and the general poor performance when used in
lift-quality BP.
I was surprised that coal was used. The various charcoals and limestone
powder were weighed and put into a large tumbler, minus the grinding media,
for a thorough mixing of the dry materials. The starch binders are added to
water and cooked to form a sticky liquid. After cooking, the sodium nitrate
is added to the liquid, followed by the mixed dry materials. All of this
composition is put into a large mixing bowl, like those found in a bakery,
and the entire batch is blended. It looked like a big batch of charcoal star
composition.
Another interesting bit of information is that the formula in these
briquettes is not the same from one mfg. plant to another. The various
plants make use of the local available natural resources and thus, the types
of wood used, the amount of retorted coal and the amount of additives can
vary. What they strive for is uniform burn performance when cooking food and
the formula is modified to give the desired uniformity.
Individual briquettes could be pressed with one of the hydraulic presses by
using a split-mold. Scoop some moist comp into the mold and press to the
desired pressure. The more interesting briquette maker consisted of multiple
cavity, rotating circular molds, that resembled ~18" diameter stainless
steel discs, about 4-5" thick. These were very heavy and were paired to give
briquettes of different shapes and sizes. These discs rotated on powered
axles that were parallel to the floor and were positioned such that the
circumferential surfaces of both circular molds were in contact with each
other.
Each wheel had machined into its outer surface, several 1/2 briquette
cavities and the wheels were timed with respect to each other, so that the
cavity on one wheel met the cavity on the other wheel at the horizontal
tangential spot between the two axles. The right wheel rotated
counterclockwise, while the left wheel rotated clockwise. This is hard to
explain, but imagine what the old-fashioned washing machine wringers looked
like. Now imagine short wringers with cavities machined into each surface.
There was a large funnel-shaped hopper above the rotating wheels, that the
moist comp was poured into. Gravity allowed the moist comp to fall into the
rotating dies, where it would fill each of the cavities. As the wheels
turned, the cavities (filled with comp) would come together and form a
rotary pressed briquette, which would fall out as the wheels separated and
continued to rotate. Overflow comp was collected at the bottom and replaced
into the hopper. I looked at this and imagined a spherical star making
machine pressing hundreds of stars a minute.
The newly pressed briquettes were collected on large screens and put into
drying ovens. Once dried, they could be tested for ease of ignition, burn
rate, heat output, etc.
It was an interesting tour.