When
an animal is alive, its skin is soft, flexible, very tough and hard
wearing: it has the ability to allow water vapour to pass out, but
it will not allow water in.
When the skin dies it loses these characteristics: if it is kept
wet it rots, and if it is dried it goes hard and brittle.
The process of tanning is to retain the skin's natural properties,
to stabilise its structure and at the same time to chemically process
it so it will no longer be subject to putrefecation. Thus, leather
is animal skin that has been treated such that its natural properties
are retained.
Skin is made up of many bundles of interwoven protein fibres which
are able to move in relation to one another when the skin is alive.
When the skin dies, these fibres tend to shrivel and stick together.
Essentially, the purpose of tanning is to permanently fix the fibres
apart by chemical treatment, and to lubricate them so they can move
in relation to one another.
Well tanned leather, therefore, retains the properties of flexibility,
toughness and wear.
It also continues to 'breathe', allowing water vapour to pass through
but remaining reasonably water-proof.
It is this characteristic which accounts for the comfort of genuine
leather shoes and clothing.
The chemistry of the leather industry
https://nzic.org.nz/app/uploads/2017/10/5C.pdf
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Commercially
used;
Acids in Oak trees for tanning the hide
Quercitannic and Gallotannic acids
Quercitannic acid is one of the two forms of tannic acid found in
oak bark and leaves.
The other form is called gallotannic acid and is found in oak galls,
https://en.wikipedia.org/wiki/Quercitannic_acid
The quercitannic acid molecule is also present in quercitron, a
yellow dye obtained from the bark of the Eastern black oak (Quercus
velutina), a forest tree indigenous in North America. It is described
as a yellowish-brown amorphous powder.
https://en.wikipedia.org/wiki/Gallotannic_acid
Commercial Tannic acid is a specific form of tannin, a type of polyphenol,
its weak acidity (pKa around 10) is due to the numerous phenol groups
in the structure, the chemical formula for commercial tannic acid
is often given as C76H52O46, which corresponds with decagalloyl
glucose, but in fact it is a mixture of polygalloyl glucoses or
polygalloyl quinic acid esters with the number of galloyl moieties
per molecule ranging from 2 up to 12 depending on the plant source
used to extract the tannic acid, commercial tannic acid is usually
extracted from any of the following plant parts:
Tara pods (Caesalpinia spinosa), gallnuts from Rhus semialata or
Quercus infectoria or Sicilian Sumac leaves (Rhus coriaria).
https://en.wikipedia.org/wiki/Tannic_acid
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How
to make leather naturally - Natural vegetable tanning
Things You'll Need; Animal skin(obviously), a large, preferably
plastic 10–20 gallon (37.9–75.7 Liter) container, plenty
of oak, hemlock, sumac, or tanoak bark, a water source, an assortment
of knives, including at least one convex blade, Lime, a rounded
stick or paddle(optional), enthusiasm and patience.
10 steps
Natural vegetable tanning, one of the best known methods of producing
leather.
Make Leather Naturally;
Step 1, Start by setting up a work area.
Step 2, Soak the hide in a bucket of water overnight to make
it more pliable.
Step 3, Carefully scrape the flesh off the skin using a very
sharp convex blade or drawknife.
Step 4, Once clean, the hide must be de-haired. Lime is usually
used to break down the keratin in the hair, making it easier to
remove, mix up a solution of 2 cups lime to 1 gallon (3.8 Liter)
water, soak the hide in the lime solution for one to two weeks,
Hair, especially deer fur, is notoriously difficult to remove, leaving
it in the solution too long might damage the skin itself, when it's
finished soaking, lay it over your work-bench and scrape the loosened
hair off the skin using a canoe paddle, drawknife, seashell or similar
implement.
Step 5, By now the hide looks clean, but is still covered
in protective layers, a membrane on the flesh side and the epidermis
on the fur side, these layers, especially the tough epidermis, must
be removed to allow the tanning solution to penetrate and fully
preserve the hide, first allow the surface of both sides to dry
out, carefully scrape the hide using sharp blades held perpendicular
to the skin, sand the surface with medium-grade sandpaper for a
more polished job and to help remove any tough spots.
Step 6, finally, the hide is ready to be tanned, collect
a large amount of oak or hemlock bark, try not to strip bark from
living trees as this can kill or severely injure the tree, with
a little exploration, you can usually find plenty of fallen trees
to collect from, also, make sure you have the right tree! Add the
bark to a large container of water, an empty trash can or plastic
box is ideal, soak the skin in this bark "tea" for up
to nine months, during this time the tannic acid in the bark will
seep through every pore in the skin, coating the microscopic fibers
with preservative, for best results, change the water and add fresh
bark once in a while, say once every three months, once it's done
tanning, remove the skin from the solution and clean it well, scrubbing
and even scraping it with a blade.
Step 7, the final part of the process, currying, is turning
the preserved but rough and poorly-colored skin into a polished
final product, to prepare for currying, poke a series of holes along
the border of the hide using a leather awl or similar instrument,
tie ropes to the holes and stretch the skin taut on a wooden frame
by fastening the ropes to the frame, In this position, the skin
will be easier to manipulate, leave it on the frame until semi-dry,
a few hours in the sun should suffice, scrape both sides vigorously
with a very blunt blade or alternatively, rub a rounded stick or
canoe paddle across the surface, this process, called sleaking,
rapidly and repeatedly stretches the leather making it permanently
soft, smooth, and supple, as the skin MUST be continuously and vigorously
sleaked until dry, the longer and more energetically the leather
is sleaked now, the better the final product will be.
Step 8, the leather can be smoked suspended over a fire of
greenwood, this isn't necessary, but it helps waterproof the leather
and darken its color, a tripod would work, but be careful not to
let the leather fall into the fire!
Step 9, Either way, the leather is finished by rubbing oil
into the surface and giving it a final round of sleaking.
Step 10, congratulations! If you completed the above steps
carefully and methodically, your finished leather should be soft,
smooth and lightweight, ready to be dyed or used as-is in your favorite
leather crafts, some examples include leather-bound books, bags
and pouches, clothes, moccasins, belts, and wall decorations.
Have fun and be creative!
https://www.wikihow.com/Make-Leather-Naturally
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Commercial
Tanning
Animal skins are converted to leather in an eight step process as
follows:
8 steps
Step 1 - Unhairing, The animal skins are steeped in an alkali solution
that breaks down the structure of the hair at its weakest point(the
root) and so removes the hair.
Step 2 - Liming, The hairless skin is immersed in a solution of
alkali and sulphide to complete the removal of the hair and to alter
the properties of the skin protein (collagen). The collagen becomes
chemically modified and swells, leaving a more open structure.
Step 3 - Deliming and Bateing, The skin structure is then opened
further by treatment with enzymes, and further unwanted material
is removed.
Step 4 - Pickling, The skins are then treated with acid to preserve
them for up to two years
Step 5 - Tanning, This is the most chemically complex step. During
tanning, the skin structure is stabilised in its open form by replacing
some of the collagen with complex ions of chromium. Depending on
the compounds used, the colour and texture of the leather changes.
When leather has been tanned it is able to 'breathe' and to withstand
100°C.(212°F.) boiling water, as well as being much more
flexible than an untreated dead skin.
Step 6 - Neutralising, Dyeing and Fat Liquoring, The leather is
then treated with alkali to neutralise it and so prevent deteroration,
and then dyed. This involves fixing a variety of compounds onto
the chromium, as that is the most reactive site present. Once the
leather is dyed, it is treated with reactive oils that attach themselves
to the fibrous structure, improving suppleness and flexibility.
Step 7 - Drying, Water is removed from the leather, and its chemical
properties stabilised.
Step 8 - Finishing, A surface coating is applied to ensure an even
colour and texture and to improve its ability to wear. Suede leather
is also buffed at this point to give it its distinctive finish. |
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Proper
Processing of Wild Game and Fish
Most outdoorsmen hunt or fish for sport, many of them also do it
to provide food for themselves and their families.
The meat from hunted animals, birds, or fish is processed and either
prepared for immediate consumption or preserved for later consumption.
Those
who field dress animals, fish, and birds and transport them from
the field are often unaware of the potential risks associated with
foodborne pathogen contamination.
As with any perishable meat, raw or undercooked game meat can contain
harmful bacteria such as salmonellae and pathogenic strains of Escherichia
coli. These bacteria, often associated with the gastrointestinal
tracts of animals, can cause illness in humans when ingested.
Contamination of meat or fish may occur through the initial wound
as well as during field dressing, handling, and transport.
Bacterial numbers will increase on the meat, especially if held
at improper temperatures. If the meat is not properly cooked or
preserved, or if cross-contamination occurs, there is an increased
risk that these pathogens will be ingested, often resulting in foodborne
illness.
Therefore, proper handling of game meat or fish from the field or
stream to the table is extremely important.
The Importance of Temperature Control
Bacteria exist everywhere in nature--in the soil, air, water, and
our food--and it can grow on that food when the temperature is right
because it provides the nutrients and other conditions bacteria
need to grow.
Temperature control plays a critical role in keeping food safe and
is essential for the prevention foodborne illness.
Bacteria grows most rapidly in the range of temperatures between
40°F.(4.444°C.) and 140°F.(60°C.), in some cases,
doubling in number every 20 minutes.
This range of temperatures is often called the "temperature
danger zone.
"The
Temperature Danger Zone: 41°-140°F.(5°-60°C.)
Temperatures below 40°F.(4.444°C.) will slow the growth
of the bacteria but will not kill them.
Bacteria capable of causing foodborne illness either do not grow
at these refrigerator temperatures or grow very slowly. However,
spoilage bacteria, yeasts, and molds will grow and cause the meat
or fish to spoil over time.
After days of refrigerated storage, meats may develop uncharacteristic
odors or colors and/or may become sticky or slimy.
Always use a refrigerator/freezer thermometer to verify that the
temperature of the refrigeration unit is below 40°F.(4.444C.)
Properly handled and prepared game meat, birds, or fish stored in
a freezer at 0°F(-17.77778C) will last up to a year or so.
Freezing prevents bacterial growth, but it does not kill them. Once
thawed, these bacteria can again become active and multiply to levels
that may lead to foodborne illness. Therefore, thawed meats should
be handled in the same manner as fresh meats.
Be sure to thaw frozen meats properly either in the refrigerator,
in a microwave, or, if vacuum packaged, under cold running water--but
never at room temperature. Cook
the meat quickly after thawing is completed.
When storing and handling meats, preventing cross-contamination
is important.
Prevent meat juice from dripping onto other food items in the refrigerator
and clean all surfaces and utensils that come in contact with the
raw meat or its juices with hot, soapy water and rinse well.
Always cook raw game meat, birds, and fish to the proper internal
temperature.
This internal temperature must be reached or exceeded during baking,
roasting, frying, or boiling in order to destroy bacteria that can
cause foodborne illness.
When roasting meat and poultry, use an oven temperature no lower
than 325°F.(162.7778°C.) Cook ground meats to an internal
temperature of at least 160°F.(71.11111°C.) Cook game bird
breast meat to an internal temperature of at least 165°F.(73.88889°C.)
Use an instant-read meat thermometer to ensure that all meats have
reached the proper internal temperature.
An uncommon but severe parasite that may be associated with bear
and wild pigs from North America is Trichinella spiralis.
The parasite can be inactivated by freezing the raw meat for at
least three weeks prior to consumption.
Cooking also will destroy the parasite.
So, bear or wild pig meat should be cooked using the same temperature
guidelines as other meats such as venison.
Once cooked, it is important to cool the meat down rapidly and then
store it at refrigeration temperatures if the food will not be consumed
immediately.
Spore-forming bacteria, such as Clostridium botulinum and Clostridium
perfringens, are a risk in cooked meat items that are not properly
chilled and stored.
Safe food-handling practices are a good defense against foodborne
illness. Because we know how different temperatures affect the growth
of bacteria in our food, we can protect ourselves and our families
from foodborne illnesses by properly handling, cooking, and storing
game meat, birds, or fish at safe temperatures.
https://extension.psu.edu/proper-processing-of-wild-game-and-fish
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Hickory
is highly prized for wood-burning stoves and chimineas because of
its high energy content.
Hickory wood is also a preferred type for smoking cured meats.
In the Southern United States, hickory is popular for cooking barbecue,
as hickory grows abundantly in the region and adds flavor to the
meat. |
Smoking
Woods
Plenty of information at the following site, a must see, Extracted
here is only the wood or other items used or not to be used for
smoking and which wood goes best with which meat and some very good
points.
http://www.deejayssmokepit.net/Woods.htm
There are many types of wood that can be used for smoking food.
I have compiled a list of ,any of these woods and what they are
recommended to be used with.
You may also find you like to use a combination of woods from you
smoked meats.
My favorite combination is Hickory, Cherry, Apple and Pecan wood.
I used this blend for just about every smoke.
I also use quite a bit of apricot, peach, maple and oak because
it’s easy for me to get for free and maintains a simpler flavor
profile as my preferred blend.
I personally find mesquite revolting. It is in ever BBQ store but
you have to use it carefully. Mesquite is very harsh and easily
becomes over powering. Gotta be a Texan to like that stuff. It’s
rather harsh like burnt sugar and a little bitter for my taste.
Wood Smoking Flavor Chart, Wood type, Smoking Flavor Characteristics,
Meats or Veggies to use wood with;
Acacia,
Alder, Almond, Apple, Apricot, Ash, Avocado, Bay, Beech, Birch,
Blackberry, Butternut, Carrotwood, Cherry, Chestnut, Corncob, Cottonwood,
Crabapple, Fig, Fruitwood, Grapefruit, Grapevines, Guava, Hickory,
Jack Daniel's Chips, Kiawe, Lemon, Lilac, Lime, Maple, Mesquite,
Mulberry, Nectarine, Oak(White and Black Jack)(RED OAK is good on
ribs), Olive, Orange, Peach, Pear, Pecan, Persimmon, Pimento, Pistachio
Nut Shells, Plum/Prune, Sassafras, Seaweed, Walnut (Black), Walnut
(English), Whiskey Barrels (Nice).
Smoking Herb Blends
Italian Herbs, Oriental Herbs, Dried Herbs.
Wood that is considered poisonous when used for smoking.
DO NOT USE any wood from conifer trees: PINE, FIR, SPRUCE, REDWOOD,
CEDAR, CYPRESS, or they will make you sick!
DO NOT USE - ELM, EUCALYPTUS, SYCAMORE, SWEET GUM TREES and LIQUID
AMBER wood is unsuitable for smoking.
More woods that you should not to use for smoking:
Never use lumber scraps, either new or used. First, you cannot know
for sure what kind of wood it is; Second, the wood may have been
chemically treated; Third, you have no idea where the wood may have
been or how it was used.
Never use any wood that has been painted or stained.
Do not use wood scraps from a furniture manufacturer as this wood
is often chemically treated.
Never use wood from old pallets. Many pallets are treated with chemicals
that can be hazardous to your health and the pallet may have been
used to carry chemicals or poison.
Avoid old wood that is covered with mold and fungus that can impart
a bad taste to your meat.
See full chart @
http://www.deejayssmokepit.net/Woods.htm
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Meat eating
animals are not good to eat. |