zxcvbob wrote:
> I agree with that. But there are lots of recipes floating around that
> call for salt and dubious amounts of saltpeter. You would be better off
> using the TQ, unless you wanted to redo the recipe using salt and prague
> powder and calculate the nitrite yourself (ignore the saltpeter in the
> original recipe)
No question about it, stay away from saltpeter. It's archaic.
I've seen substitution charts for it but I've never used them. I
just redo the recipes from the ground up using specific target
levels for salt and nitrite/nitrate.
> Tonight I'll look up a few professional curing recipes and see what the
> affect would be of leaving out the cure and subbing TQ for the salt. (I
> think it will be close, except for the sugar in the TQ.)
Not a bad idea. Let's take a shot at it.
We'll estimate the effect using a well known recipe for Smoked
Polish Sausage [1], which contains 2 t prague #1 and 5 T salt
per 10 lbs of meat.
The original recipe contains the standard 1 oz prague #1
per 25 lbs of meat, resulting in a sodium nitrite content
of 156 ppm, rounded off.
Using your rule of thumb, we'll substitute Tenderquick for
the salt and leave out the prague #1,
TQ weighs 183 g per cup [2]
5 T of TQ weighs 57.2 g
57.2 g x 0.5% (the % nitrite in TQ) = 0.2859375 g sodium nitrite
In direct addition to 10 lbs of meat, this results in
a 63 ppm sodium nitrite content.
As you can see, we've gone from 156 ppm to 63 ppm using
the rule of thumb. That's not necessarily bad. It depends.
In a recipe where nitrites are used for color and flavor, it
only has the effect of changing color and flavor. Where
nitrites are used for preservation however, it could
be a problem.
There is certainly a reduction in preservation effect by
using this substitution. It's non-linear so more calculations
are required.
Using a well known model for pathogen growth [3], specifically
for a common type known as Staphylococcus aureus, we'll
calculate the effect of lowering the amount of nitrite from
150 ppm to 63 ppm in a medium of beef broth.
First we'll assign some parameters, some of which are
intended to approximate the conditions in the sausage recipe.
These will be the same across both calculations, i.e. we will
only modify the nitrite level, leaving all other parameters
the same.
Temp: 70 F
PH: 5.6
NaCL 2%, resulting in water activity level of 0.989
Conditions are aerobic
Using the above parameters in the aforementioned mathematical
model with the original 150 ppm amount of sodium nitrite,
we get the following pathogen growth curve (data available
in table form on request):
<http://pages.sbcglobal.net/barber21/tmp/150ppm.gif>
Using the same parameters with the same model but plugging in
a 63 ppm sodium nitrite level, we get this growth curve:
<http://pages.sbcglobal.net/barber21/tmp/63ppm.gif>
There's no question that there's a reduction in anti microbial
effect with respect to S aureus. At 150 ppm, the time to
increase bacteria level by 3 logs is 59.6 hours (to locate this
on the chart, note where the line crosses the X axis at 6.0 on
the Y axis).
When the nitrite level is lowered to 63 ppm, the time shortens
to 40.1 hours. That's a reduction of about 1/3, which is
certainly significant. It shows a substantial increase in
rate of bug growth.
The moral of the story is, I think, that it's fairly safe to
experiment with nitrites where they're only used for effecting
flavor and color, but one should be much more careful when
nitrites/nitrates are included in the recipe as a preservative.
The key is knowing the difference.
Your rule of thumb is just fine in some cases, not so much
in others. It particularly begs extra attention when applied
to prague #2, i.e. dry cured recipes, where the item is not
cooked at all and one is especially dependent on the cure itself
to prevent pathogen growth. It might also be a problem in smoked
sausage recipes where botulism is a risk.
I learn a whole lot from reading your posts BTW, and I admire
your depth and breadth of knowledge.
[1] Great Sausage Recipes and Meat Curing, Rytek Kutas, 3rd
edition, page 214
[2] Common salt weights, in grams per cup
Morton Table 295
Morton Kosher 215
Morton Curing and Pickling 284
Morton TQ 183
Diamond Crystal Canning/Pickling 284
Diamond Crystal Kosher 129
Prague Powder #1 256
[3] R.L. Buchanan, J.L. Smith, C. McColgan, B.S. Marmer, M.H.
Golden and B.J. Dell, Response Surface Models for the
Effects of Temperature, pH, Sodium Chloride, and Sodium
Nitrite on the Aerobic and Anaerobic Growth of Staphylococcus
aureus 196E: Journal of Food Safety (1993) 13:159-175
http://www.arserrc.gov/MFS/HTML/ERRCPubs/5865.pdf
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