I've just done a considerable amount of reading looking for an expiration time for cures.....
Seems moisture, heat and oxygen "can" cause degradation to the nitrite... which creates nitrate...
I'm of the opinion, what we have in our curing supplies will be fine to use for years... I just finished up a 1# bag that I've had for about 15 years... and that 1# package cured ~400 #'s of meat.. of course there was a hiatus for several years until I found this great forum...
Previously I never used cure in salmon.. which I was lucky and never had a problem but now I always use cure #1 when I smoke any fish product... had I been using it in fish, the 1# package would have only lasted less than 1 year....
Now I've been reading nitrite will prevent botulism in canned products... So, I'm thinking I will start using it in canned fish, meat, beans etc. where botulism has been found previously.... Since it degrades above 130 deg. F, and testing of consumer end products at the grocery store show residual nitrite is in the 10-25 Ppm range, which is adequate for continued preservation, the cure in canned products will be minimal while the preservation of quality will be greatly improved.....
Some folks think I over react to this botulism "BS".... Well, if my home canned beans or fish caused someone's death, like my granddaughter's, for lack of 1 grams per pint cure #1, especially since I know about how nitrite prevents botulism in canned food............. that would be very tough to live with.....
Here's a factoid I just found......
Isn’t botulism one of those old
diseases that aren’t really a
problem anymore?
Botulism is rare today because processing methods
and preservatives like sodium nitrite are used to
protect consumers. In fact, since sodium nitrite was
approved for use in cured meats in 1925, no cases of
botulism have been associated with commercially
prepared cured meats. Sodium nitrite provides a food
safety benefit to consumers.
Are ‘nitrates’ used in curing
meats?
Decades ago, sodium nitrate - a "chemical cousin"
of nitrite — was also used as a curing ingredient.
Sodium nitrate, even though still permitted as an
ingredient, is rarely used to cure meat and only in
some certain specialty meat products.
Are cured meats the major
source of nitrite?
Actually, less than five percent of daily nitrite intake
comes from cured meats. Nearly 93 percent of nitrite
comes from leafy vegetables & tubers and our own
saliva. Vegetables contain nitrate, which is converted
to nitrite when it comes into contact with saliva in the
mouth.
In fact, the amount of nitrate in some vegetables
can be very high. Spinach, for example, may contain
500 to 1900 parts per million of nitrate; radishes may
contain 1500 to 1800 parts per million and lettuce may
contain 600 to 1700 parts per million. The nitrate to
nitrite conversion process from eating vegetables
makes up 85 percent of the average human dietary
nitrite intake.
By contrast, the amount of nitrite allowed by
USDA to be added to cured meats is miniscule at no
more than 156 parts per million. In most cases, the
amount added is 120 parts per million or less and after
processing the amount remaining in the final product
is typically 10 parts per million or less. This amount is
approximately one-fifth the level of 25 years ago.
There is another source of nitrite in the body. Called
the "Molecule of the Year" by Science Magazine in
1992, nitric oxide is an amazing chemical that the body
uses to control blood pressure, kill tumor cells and heal
wounds. When nitrite oxide is done with its work, its
byproduct is nitrite. So clearly, nitrite is something
that is made by the body as part of its normal, healthy
processes.