In the grand scheme of things, making our
Sojos natural pet food mixes is a
relatively simple process. We source the ingredients
(typically in 50 lb. sacks), carefully blend them together
in the correct proportions, bag the mix, and it’s ready
to go. After all, the whole point of fresh, raw
pet food is to leave the ingredients
in tact so that the naturally-occurring nutrients and enzymes
are present. On the other hand, manufacturing
kibble or extruded pellets is not quite as simple. It is
an extremely complicated process, the end result of which
is quite different than the original ingredients used.
So
how in the heck are those little mystery pellets made? Well
it all starts with a bunch of dry ingredients. Because extruded
pet food is made in massive quantities, ingredients are purchased
by the truck-load and are typically stored in silos. The first
step in making extruded pet food is that a machine called a
hammer mill grinds the ingredients to a precise size so that
they can be used to create a completely homogenous product.
If the particles are too small or too large, they won’t
absorb the correct proportion of water and the kibble won’t
cook correctly. Typically ingredients are ground to the size
of coarse flour.
Next the ingredients are blended together
using a machine called a ribbon mixer (which is the same machine
that Sojourner Farms
uses to mix ingredients in our natural pet food). Computers
control the scales and assure precise proportions of each ingredient.
Next the mixture must be pre-conditioned
before moving onto the extrusion process. Preconditioning is
the process by which
the dry ingredients are mixed together with wet ingredients
including the fats and the meat along with hot water and pressurized
steam. This hot water and steam begins the cooking process,
and the starch in the ingredients begins to gelatinize. Approximately
1/4 of the cooking takes place at this time. Once preconditioned,
the ingredients are ready for extrusion.
The extruder is like
a massive metal tube with a giant screw inside of it. Originally
these machines were designed for the
plastics industry. Dough is fed in one end and on the other
end is a die, which determines the shape of the kibble. The
walls of the tube are heated to a high-temperature so that
the ingredients cook as they touch the wall, moving through
the tube as they’re propelled forward by the screw. The
tube is also filled to the point where there is a massive amount
of pressure inside, which, along with the heated walls of the
tube brings the dough to extremely high temperatures. This
typically causes the naturally-occurring nutrients to be destroyed.
As the dough is squeezed out through the die and cut by a knife,
it is released from the pressure and hits open air. This causes
the kibble to expand about 50%. These puffed-up kibbles are
hot and soft.
Finally a process called enrobing occurs.
The food goes into dryers where it is hardened. Because much
of
the nutrition
has been cooked out of the kibble, synthetically-formulated
nutrients must be sprayed on, along with flavor enhancers in
the form of liquids or powders. Now the kibble dries again,
and finally it is ready to be weighed and bagged.
So what are
the pros and cons of extruded food? The number one advantage
is convenience. Much like fast food for humans,
kibble doesn’t require a lot of effort. You simply open
the bag and pour it into a bowl. The other advantage is a relatively
long shelf life, due to the high heat and preservatives that
have been applied during processing. The down-side to kibble
is that you don’t get any of the naturally-occurring
nutrients which are destroyed during all of the pulverizing,
processing, cooking, and preserving that goes on. Synthetic
nutrients aren’t as easily absorbed by the body and,
despite kibble’s long shelf-life, synthetic nutrients
are less shelf-stable and can be destroyed during storage or
shipping. Another disadvantage is that the artificial preservatives
used in kibble can cause dog health
problems. It’s also
important to beware of a product trying to extend shelf-life
by using
natural
preservatives like vitamin E, as they aren’t as shelf-stable
and can spoil or lose their effectiveness over time.
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Sojourner Farms. All rights reserved.
