# Spreadsheets for Curing Meat, Science



## webmanoffesto (Apr 25, 2019)

I'm looking for a more scientific and numbers based approach. 
First of all, by listing all recipes in grams, which makes conversion to percentages easy.
I wish more sources would do this.
My "recipe formulas" are based on Ruhlman's.
http://ruhlman.com/2010/03/corned-beef-how-to-cure-your-own/
Do these look correct to you? What other resources can I use to confirm my formulas?

Somewhere I read that beef is 70% water. 
So I start with Beef.Weight.in.Grams x 0.70 = Water.in.Beef
Then I do 
(Water.I.Will.Add.for.Wet.Cure + Water.in.Beef) = Total.Water
Total.Water x .03 = Salt.I.Will.Add
Total.Water x 0.00175 = Salt.Num.1 

I can even calculate the spice mix, for example
Total.Water * 0.0095 = Spice.Mix.to.Add 
The percentage will, of course, change when I use different spice mixes.


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## indaswamp (Apr 25, 2019)

do not multiply meat weight by 0.7.... 
use:
Meat weight + water you will add = weigh needed to calculate cure to add.


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## chopsaw (Apr 25, 2019)

I have his book , and after finding what I consider to be wrong amounts and bad info , I don't use it .


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## webmanoffesto (Apr 25, 2019)

Thanks, I revised my formulas now

Corned Beef Calculations   
Formulas
Meat_Weight_Pounds    10
Meat_Weight_Grams    =B2*453.5924
Water_in_Meat    =B3*0.7
Water_to_add_mL    1000
Total_Water    =SUM(B3:B5)
Total_Salt_Needed    =Meat_Weight_Grams+Water_to_add_mL*0.03
Pink_Salt_Needed    =(Meat_Weight_Grams+Water_to_add_mL)*0.00175
Spice_Mix_Needed    =Meat_Weight_Grams*0.0095

Corned Beef Calculations           
Example
Meat_Weight_Pounds    10       
Meat_Weight_Grams    4535.92       
Water_in_Meat    3175.15    Don't Use. Use Meat_Weight_Grams.   
Water_to_add_mL    1000       
Total_Water    8711.07    Don't use this. Use Meat_Weight_Grams + Water_to_add_mL   
Total_Salt_Needed    4565.92       
Pink_Salt_Needed    9.69       
Spice_Mix_Needed    43.09


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## PolishDeli (Apr 25, 2019)

Is your salt equation missing parentheses?  4000+g of NaCl won’t dissolve in 1L of H2O.  
But either way, I don’t understand the salt equation for two reasons.   (1) It takes the meat weight into account and (2) it seems not to take the salt in Cure#1 into account (Cure# 1 = 93.75% NaCl + 6.25% NaNO2). 
I determine how much NaCl to add based on a targeted salinometer value [°SAL].  You can convert between %NaCl and °SAL according to: 
%NaCl = 100* NaCl [g] / (NaCl [g] + H2O [g]) = 100*0.00264*°SAL

I determine how much Cure#1 to add by targeting a ppm level of NaNO2.
If I’m making sausages, I use this equation:
NaNO2 pmm = 1000000*(.0625*Cure#1 [g] )/Meat Weight [g]

If, on the other hand, I’m doing an immersion/injection cure:
NaNO2 ppm = 1000000*0.1*(.0625*Cure#1 [g] )/Brine weight [g]
(Note, the constant 0.1 is from injecting the meat with an amount of brine equal to 10% of the meat weight)
Others would use this equation:
NaNO2 ppm = 1000000*(0.0625*Cure#1 [g] )/(Brine weight [g]+Meat weight [g])


You’d probably appreciate this book:
Home Production of Quality Meats and Sausages  by S Marianski  & A Marianski


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## JC in GB (Apr 25, 2019)

Here is a document I downloaded that has the FDA inspection methods and formulas.  Use it as you see fit.

Also, I made a curing calculator in Python 3 language.  I would be happy to share the source code with you.

I was able to download a Python interpreter so I can run my calculator on my phone.

I can also list the formulas here if you want to do the number crunching manually.


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## JC in GB (Apr 25, 2019)

Calculator had bad formulas...  Fixing.....  Be back soon.....


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## daveomak (Apr 25, 2019)

Please don't use Rhulman's numbers....  He's a writer... He doesn't know squat about curing meats....  
A very simple approach to curing meat is...
1.13 grams cure#1 per pound of meat
1.13 grams cure#1 per pound of water added for a brine cure solution...
18 grams of kosher salt per pound of meat for a 2% salt...
9 grams of sugar per pound of meat for a 1% sugar...

You will not go wrong using those numbers...


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## daveomak (Apr 25, 2019)

JC, check your calcs....  something is haywire....  Dave

Here is what I got for a 5 kg roast at 156 PPM using 1 liter of water.

NaCl: 187.16 g  *wrong.. .0175 x 6,000 = 105 grams salt...*
Cure #1: 24.96 g  *wrong...  6,000 x 0.0025 = 15 grams cure#1... for 156 Ppm nitrite*
Sugar: 50.50 g       *wrong... 6,000 x 0.01 = 60 grams sugar...
You need to check your spreadsheet....*

This will give you a 1.75% salt concentration and a 1% sugar concentration in your finished product and provide 156 PPM NaNO2.


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## JC in GB (Apr 25, 2019)

daveomak said:


> JC, check your calcs....  something is haywire....  Dave
> 
> Here is what I got for a 5 kg roast at 156 PPM using 1 liter of water.
> 
> ...




Thanks for that post...  I went back and checked and found that I somehow screwed up my formulas when I updated the calculator.

I am going to find out where I messed it up and fix it....  I am glad I didn't try and use it yet...  Zounds!


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## webmanoffesto (Apr 25, 2019)

View spreadsheet in progress here. View only.

Note: It's cool that when I past the link to the Google Sheet here it is embedded in the forum post and it automatically updates when I update the Google Sheet.


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## webmanoffesto (Apr 25, 2019)

daveomak said:


> 18 grams of kosher salt per pound of meat for a 2% salt...


Do you recommend a 2% solution for curing most meats and fish?
I see many percents thrown around. But it seems like they often "over-salt" because of inexact recipes.

I'm fine doing a 2% or 3% wet cure overnight and then doing a refrigerator-dry for an additional 12-24 hours.

One online source, which seemed very scientific (and I can't seem to find again) claimed that wet cure is much safer than dry cure. I think the logic was simply that a wet cure makes sure the salt and Cure#1/PragueSalt get spread around correctly.


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## webmanoffesto (Apr 25, 2019)

JC in GB said:


> I was able to download a Python interpreter so I can run my calculator on my phone.


Please send me, or post your Python code.


JC in GB said:


> I can also list the formulas here if you want to do the number crunching manually.


Yes, please list the formulas here.


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## JC in GB (Apr 25, 2019)

webmanoffesto said:


> Please send me, or post your Python code.
> 
> Yes, please list the formulas here.




I will have to verify my formulas.  My calculator was working fine then I added some "improvements" that messed it up.  I will have it done tomorrow with a bit of luck.


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## indaswamp (Apr 25, 2019)

One thing I will add here is that you should subtract the weight of the bones...the bones will not absorb any NaNO2. For a whole Turkey, the bones are about 37% of the weight of the bird. A Boston but is usually 0.5~0.75 lbs. for a 10lb. butt....

Until I started doing this, my cured turkeys were always a little saltier than I expected them to be.


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## daveomak (Apr 25, 2019)

I calculate the salt to 1.75% and add the cure#1...  cure#1 is 0.25% salt at an addition of 0.25% which comes out to 156 Ppm...  Soooooo, the 1.75 and the 0.25% comes out to 2%...  The 1% sugar buffers any saltiness...  
Swamp is spot on with the bone thing...  Same with pig skin....  When you get into this...  use a value, note the condition of the meat...  bone in.... skin on... etc...  if you want you can weigh the bones etc, add that info to your note book..  make any adjustments necessary....  ALSO, read the label on any meats to see how much stuff they add...  What I do is try and find meats with nothing added.....


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## webmanoffesto (Apr 25, 2019)

daveomak said:


> I calculate the salt to 1.75% and add the cure#1...  cure#1 is 0.25% salt at an addition of 0.25% which comes out to 156 Ppm...  Soooooo, the 1.75 and the 0.25% comes out to 2%...


I guess you're saying that Cure #1 is mostly salt, so 
"How much salt to add" =  "Salt" + "Cure #1". 
Conversely, If I don't count "Cure #1" as part of the salt, then my meat may come out too salty.
"Instacure 1 contains 6.25% sodium nitrite and 93.75% salt." https://tinyurl.com/mn6dfn9

I prefer my wet cure to have no sugar. Am I correct in saying that the sugar doesn't play a role in the preserving, it's just for taste.


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## daveomak (Apr 25, 2019)

The sugar is hygroscopic.... It attracts and holds moisture... so does the salt....  So, it's a win-win...  the sugar "hides" some saltiness and keeps stuff moist...  I find it a balancing act..  salt, sugar... flavor profile...


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## indaswamp (Apr 25, 2019)

daveomak said:


> When you get into this... use a value, note the condition of the meat... bone in.... skin on... etc... if you want you can weigh the bones etc, add that info to your note book.. make any adjustments necessary....


Yep....that is how I know the bones of a turkey are roughly 37% of the weight of the bird... I weighed the bones after boiling them down for a gumbo on a turkey I smoked a while back....


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## JC in GB (Apr 26, 2019)

Okay here are some calculations I used for my calculator.  I believe I figured out why my program gave bad output.  I accidentally got rid of the brine weight calculation which threw the final results off.  Will be repairing that as soon as I get a moment...

Calculation to find weight of NaCl for an x% brine:

NaCl = (H2Oltr * brine%)/abs(brine% - 1)

Calculation for PPM:

ppm = mg/kg

Calculation for milligrams of NaNO2 needed for given PPM:

NaNO2 = H2Okg * ppm

Calculation for grams of cure #1 needed for target PPM:

Cure#1 = (NaNO2  * 16)/1000

NaCl + cure#1 needed for curing brine:

NaCl = (NaCl - cure#1)

Brine weight:

Brine kg = H2Okg + NaCl + cure#1


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## webmanoffesto (Apr 26, 2019)

Should the same ratios be used for curing fish, such as cold smoked salmon?
Meaning the ratios of fish : salt : Cure #1


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## daveomak (Apr 26, 2019)

Up to 200 Ppm nitrite is allowed in salmon..  That's what I use for ratios...


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## webmanoffesto (Apr 27, 2019)

JC in GB said:


> Okay here are some calculations I used for my calculator


Wow, that's amazing, thank you!


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## PolishDeli (Apr 29, 2019)

webmanoffesto,

JCinGB has already got you covered with his Python calculator.
But if you're a spreadsheet guy, here is another calculator to throw into the mix.
It’s a version of the one I built for my own use; but cleaned up a bit.

The excel file allows users to select between different input units, and to select between %-pickup, equilibrium, or dry curing calculations.  I hope it’s self-explanatory.
Let me know if you find any errors.


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## parson snows (May 15, 2019)

PolishDeli,
am I missing something? 
I can't seem to find a link to the spreadsheet (excel file) that is mentioned above.
regards


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## PolishDeli (May 16, 2019)

Hi Parson,

I removed that version.  
It’s a work in progress, as I continue modifying it for my own utility.
Here is an updated file.  Let me know how it works for you.


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## JC in GB (May 16, 2019)

Thanks PolishD for that update.

I love to explore the math and science behind food prep.  What a great forum group to discuss such things.  

I figured out the flaw in my calculation program.  If the meat to water ratio isn't 10:1, the calculation breaks down if you don't match the pick-up %.  I think I will change it to tell you how much H2O to use instead of asking what the user has.

Also, I think that I was trying too broadly to interpret the pick-up versus equilibrium curing.

My next iteration of the program will only cover injection brining.


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## parson snows (May 16, 2019)

PolishDeli said:


> Hi Parson,
> 
> I removed that version.
> It’s a work in progress, as I continue modifying it for my own utility.
> Here is an updated file.  Let me know how it works for you.


Hi PolishDeli
Thanks for the updated file, I have downloaded it and will have a look over it. 
If I find anything questionable etc. I will let you know, along with how it worked for me.
regards


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## daveomak (May 16, 2019)

% pick up doesn't work too well...   Different cuts of meat absorb liquid at different %'s....  
Equilibrium works well...   Physics is pretty much fool proof...
Injection is pretty much absolute...  Stuff in = stuff absorbed...


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## JC in GB (May 16, 2019)

daveomak said:


> % pick up doesn't work too well...   Different cuts of meat absorb liquid at different %'s....
> Equilibrium works well...   Physics is pretty much fool proof...
> Injection is pretty much absolute...  Stuff in = stuff absorbed...



Right you are.  I have been learning a lot and am very grateful for your sanity checks on this stuff.

JC


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## daveomak (May 16, 2019)

FWIW, % pick up, in USDA terminology, is the amount that has been injected and stays in the meat....  
The commercial processors inject meats with an auto injector...  a tub of meat is weighed, then injected, and reweighed...  They do that to assure the percentages are correct of the ingredients..  
It has nothing to do with meat that has been submerged in a brine solution....  I know some folks interpret "% pick up" incorrectly....


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