by **dougal** » Sun Aug 06, 2006 4:57 pm

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.