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Why Salt Preserves Meat
While today salting meat as a method of preservation is generally only commonly used in such things
as salted pork and the like, salt has been used as the primary method of preserving meats
and various other foods as far back as history records.
Salt has a preservative effect thanks to the osmotic pressure it creates via absorption.
For example, if you take a red blood cell and place it in water, thanks to osmotic pressure
and the fact that the cell membrane is thin and semipermeable, the cell with its relatively
salty interior next to the pure water will gradually absorb more and more water until
it explodes. On the flipside, if you place that same red
blood cell into water that is saltier than the cell’s interior liquid, the reverse
will happen and the cell will gradually lose water, shriveling up in the process. Place
it in water that has the same sodium level as the cell, and nothing at all will happen.
This same effect will happen with most mold and microbes. So if you use the salt for its
absorption effect to increase the osmotic pressure, these things that may spoil the
meat will have trouble surviving and reproducing as their moisture is sucked from them. The
more salt added to the item (or sugar, which has the same effect and is often used to help
get around the strong salt flavor), the longer the preservative effect will last.
You can also observe this absorption effect simply by taking some cotton candy and placing
it in a humid environment. With just 33% relative humidity, cotton candy left out in the air
will completely collapse and crystallize in just 3 days as it absorbs the moisture in
the air. At 45% relative humidity, it will completely collapse in just one day. At 75"00:01:33,980 --> 00:01:39,390 humidity, it takes just 1 hour. This is why it has only been since 1972 that non-”made
on demand” cotton candy has been available. (1972 was when the first fully automated cotton
candy machine was invented that could make the fluffy treat and quickly package it in
water tight containers). If you’re wondering how to salt meat for
preservation, the process is fairly simple and straightforward, though there are a variety
of variations on the basic method used to improve flavor. In general, you simply rinse
the fresh meat in cold or lukewarm water, then pour a thin layer of salt (generally
kosher salt) all over the meat and rub it in. Next, hang or set the meat out in a cool
environment (under 60 degrees Fahrenheit, but not below freezing) for a couple weeks
to dry it out a bit. Finally, before cooking the meat, rinse off the salt with water.
In theory, if you use enough salt or sugar when doing this, you can even preserve meat
for decades, though of course the amount you’d have to use would probably make it unpalatable.
At the minimum, if you’re only using salt or sugar with no other preservative method
like smoking or the like, it’s generally considered that about a 20% salt concentration
on the surface of the meat is needed to kill off most types of microbes and fungi that
can spoil food quickly. Bonus Facts:
• In the 18th century, salted beef or horse meat (usually low quality) eaten on sailing
vessels as part of daily rations was called “salt junk” or just “junk”, making
it technically the first food item called “junk food”. Around a century later “junk”
had spread to refer to anything of low quality, though it wouldn’t be until around the 1970s
that people would commonly start calling certain food items low in nutritional value “junk
food”. • Pickling meat and other items usually
uses a salt/acidic method to achieve preservative effects, often using some sort of vinegar
for the acidic element, which further creates an environment that most microbes and fungi
have trouble surviving in. The most popular commercially available item that still uses
this technique is pickles. This is usually done by first soaking cucumbers in a salt
water brine (generally about 10% salt) for a few days, then rinsing the cucumbers off
with purified water. Next, placing the cucumbers in vinegar and sealing them in airtight jars.