FDA PROCESSING INSPECTORS' CALCULATIONS HANDBOOK

[Oddley]

Whilst struggling with the question of pickup and equalisation in brine cured meats. Or why some meats are saltier than other's using the same cure. So to help explain these questions I would like to post the address of the FDA PROCESSING INSPECTORS' CALCULATIONS HANDBOOK containing all the calculations for curing, plus lots of information.

http://www.fsis.usda.gov/OPPDE/rdad/FSI ... 7620-3.pdf
EDIT BY SPUDDY: PLEASE NOTE Its *American*, so where it says "gallons" and "pints" - they are NOT the same as the UK 'Imperial' measures.
1 US gallon = 0.832673844 Imperial (UK) gallons

Moderators I think this is important enough to make a sticky.

[sausagemaker]

Hi Oddley

Thanks for the link

Regards
Sausagemaker

[DarrinG]

Thanks for the link Oddley,

Just finished printing it off.

DarrinG

[Spuddy]

Nice one Oddley
I agree, a stickie it is.
BR

[dougal]

Just a brief reminder:

Its *American*, so where it says "gallons" and "pints" - they are NOT the same as the UK 'Imperial' measures.
1 US gallon = 0.832673844 Imperial (UK) gallons

but Google will do any such conversions for you

[saucisson]

Good point Dougal, is it worth adding that to the sticky Spuddy?

Dave

[dougal]

I think that the first post ought to be further edited to add a "health warning" to the effect that the description of the arithmetic is very far from conventional.
If this is to be a reference to which newbies are steered - they also need to be warned.

For an example of something typical
(found at the bottom ot the page numbered 15 {page 20 of the PDF})
to calculate the proportion of nitrite expressed in parts per million, the book offers:

lb cure mix x % nitrite in mix x 1,000,000 = ppm
green weight of meat block

If there is 6.25% Nitrite in your cure mix
and you put in "6.25" into the formula where it says "% nitrite in mix"
then you will get the wrong answer.
In fact, you'd get 100 times too big an answer.

For the arithmetic to be correct you *must* use the *proportion* of nitrite
ie for 6.25% you would have to use 0.0625
This would appear to be the case in all the book's formulae that I have looked at, whether referring to "% nitrate", "% pump", "% pickup", and so on.
It is a bizarrely inexplicable misuse of the % symbol.


Also worth noting in the example formula
They specify "pounds" as the unit for the weight of cure.
And no units whatsoever for the meat weight.
In this simple formula, what matters is that the same units are to be used for the weight of cure and meat. You could equally well (and probably more easily) use grammes for both in this formula.

Sadly, if you just dip into this thing and apply a formula without examining it carefully (and ideally following through a worked example) you may well get the wrong answer. And you may also do many unnecessary measurement unit conversions.

[JerBear]

D'oh, accidentally printed the whole thing

*smacks forehead!*

[wheels]

Oops! At least it'll be easier to read in bed!

Phil