Bacon curing - validating the 10% uptake assumption

Discussion in 'Food Safety' started by wade, Jan 28, 2015.

  1. But you could exceed 10% pick-up a bit in that example and still be within the limit.
    If folks don't understand, it's their responsibility to ask questions or do the research..or...pick a better curing method.
     
    Last edited: Feb 16, 2015
  2. atomicsmoke

    atomicsmoke Master of the Pit OTBS Member

    I will stop here. We talked this to death in a different thread. I won't hijack Wade's work after all the time and expense he put in. His test result will put this to rest.
     
    Last edited: Feb 16, 2015

  3. I'm following forum rules, which is not always what I follow in 'real' life.
    In matters of food safety the USDA/FSIS rules and such are to be respected in this forum.
    I don't immersion cure that way, it's a crappy way to cure for several reasons.
     
    Last edited: Feb 16, 2015
  4. Put what to rest?

    It's forum policy to follow USDA/FSIS rules and methods as I said above.
    I certainly have never said i agree with all that the 'rulers' (USDA/FSIS) spew, I don't, but it is what it is and we have to deal with it or move on.

    No tests will change that.
     
    Last edited: Feb 16, 2015
  5. snorkelinggirl

    snorkelinggirl Master of the Pit OTBS Member

    OK, so I'm getting really confused here.

    I personally don't understand the whole 10% pickup thing, but I've tried to stay away from it by sticking with immersion equilibrium curing.  I use Martin's cure calculator but use the weight of the meat + weight of the water, put in the correct ppm of nitrite per the USDA depending on whether I am curing ham or bacon or whatnot, and then leave the meat in the brine for a long time to hopefully reach equilibrium (7 days per inch of thickness, and injecting around bones or if the meat was over around 2" thick).  I don't mean to be derailing Wade's thread in any way, but is this not a more robust way of curing?  
     
  6. wade

    wade Master of the Pit OTBS Member SMF Premier Member

    When you say the weight of the water are you meaning the increase in weight of the meat as the brine is absorbed? If so I guess you would need to be weighing the meat daily when it is in the brine to see when it has absorbed the right amount of brine to result in your required calculated final Ppm.
     
    Last edited: Feb 17, 2015
  7. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Wade, morning.... The weight of the water in the brine solution... weigh the meat and water and make it up to what ever Ppm nitrite for curing, you need.... Do an equilibrium cure...
     
  8. wade

    wade Master of the Pit OTBS Member SMF Premier Member

    I think I may be getting confused here - or maybe people are talking about different things. Are you saying that for the calculation the total weight of water in the brine in SnorkelingGirls post is the same as brine uptake in the equation in Martins posts?
     
  9. snorkelinggirl

    snorkelinggirl Master of the Pit OTBS Member

    There is no calculation of pickup % or brine uptake required when you do equilibrium curing.  You have to make the assumption that, given adequate curing time, the meat and the brine will reach an equilibrium state in regards to diffusion of salt and nitrite.  Inputs to the calculation are the desired salt % in the meat (based on your taste buds and any food safety considerations), nitrite ppm (based on USDA food safety specifications), the weight of the water used to make the brine, the weight of your meat, and the % of nitrite in your curing product (i.e. Cure #1).  The outputs of the calculation are the actual weight of salt and the weight of Cure #1 required to achieve your desired nitrite ppm level and salt %, assuming that you give adequate time for the salt and nitrite in the meat and brine to reach an equilibrium state.  Please see Martin's cure calculator for the actual equation.  

    To my mind, this is a far safer and more predictable way to cure.  My understanding, which may not be correct, is that commercial producers of cured meat don't use this method because it takes too long and is therefore impractical when dealing with large volumes of curing meat.  But for the home producer, it is safer, better, and gets you away from having to be concerned that you are pulling your meat from the brine a day too early or too late.  You cannot overcure meat when using equilibrium curing, in theory.  And as long as you allow long enough cure time, you will also not undercure. 
     
    diggingdogfarm likes this.
  10. atomicsmoke

    atomicsmoke Master of the Pit OTBS Member

    Both the equilibrium and the "full strength" brines are immersion brines. Meat will pick up brine in both cases. That was what determined Wade and I to start asking questions.

    SnorkelingGirl
    If you check the recent "Prague Powder #1" thread this will make more sense.
     
    Last edited: Feb 17, 2015
  11. daveomak

    daveomak Smoking Guru OTBS Member SMF Premier Member

    Snorkeling Girl doesn't need to check that post.... She understands curing perfectly.....
     
  12. atomicsmoke

    atomicsmoke Master of the Pit OTBS Member

    I meant for her to understand the point of this discussion not curing in general. Sheesh...everyone is edgy these days.
     
  13. wade

    wade Master of the Pit OTBS Member SMF Premier Member

    Hi SnorkelingGirl. So you are calculating the immersion brine concentration to be the same as the final desired concentration - which makes total sense. The question here though is about using the 10x concentrated brine for immersion curing. I agree with you - when using the equilibrium brining at the required final strength, like dry curing, it is highly unlikely that you will exceed the strength of the cure in the brine no matter how long it is cured for.
     
    Last edited: Feb 17, 2015
  14. wade

    wade Master of the Pit OTBS Member SMF Premier Member

    After 5 days if resting in the fridge the 14 day cure batches were ready for slicing.

    Before slicing each batch was again weighed to see if there was any weight loss as the meat drained during the rest period. There was a very slight weight loss in all immersion cured batches which was  an average of 1.6% for the Loin and 3% for the belly. There was no weight loss with the Dry cure batches.

    Each batch was sliced individually with the test samples taken from the centre of the joint. All equipment and surfaces were washed down between batches being sliced to avoid any cross contamination.


    The picture above shows - On the left the loin and belly from Brine 1 - In the centre the Loin and belly from Brine 2 and on the right the loin and belly that was Dry Cured.

    It is not as noticeable in the photo but the colour of the Dry cure was a mach deeper red than either of the immersion cured joints.

    All samples are now frozen and will be delivered to the testing labs on Monday. Their turn around time is quoted as 10 days so I guess the next update will be in a couple of weeks.
     
    Last edited: Feb 21, 2015
  15. pops6927

    pops6927 Smoking Guru Staff Member Moderator Group Lead OTBS Member SMF Premier Member

    In response to curing questions on ppm, here is the FSIS explanation:

    Here is the way to calculate PPM:

    *USDA Processing Inspectors' Calculations Handbook, page 7: Nitrite x 10% pump x 1,000,000 / weight of brine = ppm

    First you need to find out how much Sodium Nitrite is in a specific amount of Cure. Let's say that we want to use 3oz of
    InstaCure#1. You have to find what 3 oz is in LBS, this is done by dividing 3 by 16 (because there are 16 ozs in a pound),
    this comes to 0.1875 lbs.

    Cure #1 has 6.25% Sodium Nitrite. So, to find out how much Nitrite is in that 0.1875 lbs of Cure, multiply 0.1875 by that
    percentage as a decimal… 0.1875 x 0.0625 = 0.01171 lbs Sodium Nitrite in 3 oz Cure.

    The ‘weight of brine’ is simply how heavy the water/brine is… One gallon of water weighs approximately 8.33 lbs.

    Now to find the Parts Per Million (ppm), here is the formula:

    multiply nitrites by % pump by 1,000,000 and DIVIDE it by the weight of your brine.

    Here is the ppm formula for 3 oz Cure#1:

    Nitrite x 10% pump x 1,000,000 / weight of brine = parts per million
    0.01171 x 0.10 x 1,000,000 / 8.33 = ppm
    0.001171 x 1,000,000 / 8.33 = ppm
    1171 / 8.33 = ppm

    140 ppm nitrite in 1 gallon of water when using 3 oz of Cure#1.

    My brine is considerably lower, 1/3rd as much.  My dad argued, and won, with the State of NY Meat Inspection that his lower nitrite brine was safe and effective when left to cure longer and would produce a more tender, more flavorful, product and was allowed to continue for 40 years.

    For the Metric side of the world:

    *USDA Processing Inspectors' Calculations Handbook, page 7:

    Nitrite x 10% pump x 1,000,000 / weight of brine = ppm

    First, you need to find out how much Sodium Nitrite is in a specific amount of Cure.

    Let's say that we want to use 85g of InstaCure#1. InstaCure #1 has 6.25% Sodium Nitrite.

    So, to find out how much Nitrite is in that 85 grams of Cure, multiply 85 by 6.25% as a decimal… 85 x 0.0625 = 5.3125g Sodium Nitrite in 85g Cure.

    The ‘weight of brine’ is simply how heavy the water/brine is… One gallon (3.78 l) of water weighs approximately 3,778g.

    Now to find the Parts Per Million (ppm), here is the formula: multiply nitrites by % pump by 1,000,000 and DIVIDE it by the weight of your brine.

    Here is the ppm formula for 85g Cure#1:

    Nitrite x 10% pump x 1,000,000 / weight of brine = parts per million 5.3125 x 0.10 x 1,000,000 / 3,778 = ppm 0.53125 x 1,000,000 / 3,778 = ppm 531,250 / 3,778 = ppm

    140 ppm nitrite in 1 gallon (3.78 l) of water when using 85 grams of Cure#1. 
     
    Last edited: Feb 21, 2015
  16. danmcg

    danmcg Master of the Pit OTBS Member SMF Premier Member

    Looking forward to your final results Wade
     
  17. pops6927

    pops6927 Smoking Guru Staff Member Moderator Group Lead OTBS Member SMF Premier Member

    Explanation of Brine Pump:



    This is when you first Introduce your meat to curing brine.  Then, you let soak, then smoke it to 146° fully cooked.  Let cool and drip, then weigh the final product.  If you have added more weight than the original weight, it can be labeled 10% (or 20% or 30%) Water Added Product, depending on the final weight.  At my dad's store, we added approx. 10% pump, and likewise took that out during smoking so the final weight was always right around 0% gain.
     
    Last edited: Feb 22, 2015
  18. Gentlemen, if nothing else, all this discussion, and examples is giving me a much better understanding of the methods for brine curing, still beating around a couple questions. If you calculate for an equilibrium brine, say for a ham (seems I will be doing a couple hams), and you inject that brine at the pre equalized concentration, due to the meat thickness and to get around/closer to bones and joints(its been recommended here in many threads to inject if there is more than 2" thickness edge to center?) Then allow it to soak for the recommended time, is this still an equalization (Because the brine was calculated for an equalization cure) or a pump method (because the liquid was injected, thus increasing the weight of the ham)?
     
  19. wade

    wade Master of the Pit OTBS Member SMF Premier Member

    Thanks for the Brine Pump Rate Chart Pops [​IMG]

    Some general comments about the purpose of this thread.

    A quick summary of the ways that various folks on here been discussing regarding curing a piece of pork to make bacon.
    1. Dry curing - An exact amount of Nitrite is combined with a desired amount of salt and sugar which is then applied to the surface of the meat and is allowed to diffuse into the meat until an equilibrium is reached.
    2. Immersion curing - The meat is totally immersed in a brine that contains a known concentration of Nitrite, salt and sugar. It is left in the brine for a period of time to allow the cure to diffuse into the meat. There are different calculations used for this though - see below.
    3. Injection brining - A known volume of concentrated brine is injected into the meat and it is allowed to diffuse through it until an equilibrium is reached.
    4. A combination of 2 and 3.
    The testing in this thread is only focusing on the Immersion curing method (2) and is looking to check (through lab testing) the actual resulting amount of cure that is in a piece of pork using two of the immersion brining methods that have been endorsed by members of the forum.
    • Pop's Low Salt brine.
      • This uses an initial brine strength of 280 mg/litre Nitrite*
      • It uses a lower Nitrite concentration (1/3) than the one his father used and regularly had lab test for 40 years
    • The brine calculation from DDF post in the Prague Powder #1  thread
      • This uses a much higher brine strength of 1,800 mg/litre Nitrite* 
      • The method is described in the USDA Processing Inspectors' Calculations Handbook as a valid way of calculating cure uptake
    * - I am using mg/litre Nitrite here instead of Ppm to avoid the different opinions regarding Ppm caclulation. People can apply their own preferred calculation to these figures, though the slight difference between the calculated mg/litre and Ppm is not significant for the purposes of this discussion.

    With the two brines being so different in strength (one being almost 10 times the concentration of the other) it raised some questions about how both recognised methods of curing, using similar immersion techniques, could both  end up with residual Nitrite levels within the meat that were within the FDA guidelines? Did one end up at the very top end and the other at the very bottom of the range?

    Both use different principles to calculate the levels of resulting levels of Nitrite.
    • Pops effectively uses equilibrium brining that allows the cure in the brine to diffuse through the meat until it approaches an equilibrium with the brine around it. This is what SnorkelingGirl was describing earlier.
    • The "Prague Powder #1" thread method works on the principle of % pickup, where the meat only picks up a %age of the cure from the surrounding brine. The USDA Processing Inspectors' Calculations Handbook states on page 22 that the % pickup is calculated as being the the increase in weight of the meat as it absorbs the brine while immersed. This is generally considered to be around 10%
    That leaves us with a bit of a dilemma.
    • If the % pickup calculation is applied to Pop's brine method then the resulting residual Nitrite would only be in the region of 28 mg/Kg (Ppm) - The low end of the USDA scale for Nitrite is 40 Ppm.
    • If the equilibrium calculation was applied to the "Prague Powder #1" brine then the resulting residual Nitrite would be approaching 1,800 Ppm - The high end of the scale for Nitrite is 200 Ppm.
    Which is right? Are they both right? The only way to see was to test them both. 
     
    Last edited: Feb 22, 2015
  20. Hi,

    I think this is a worthwhile experiment to undertake - so thanks for doing this. But it does raise another question worth considering:

    If a manufacturer claims that cure #1 is 6.25% nitrite in a package mixed with salt, then how can we be sure that every gram we take out is exactly 93.75% salt and 6.25% nitrite. There must be an assumption level built on statistical evidence which we assume is correct, otherwise we would have no confidence in using cure.

    I don't mean to take away from this thread, but I was afraid i would forget and my point is that sometimes we need to go on assumptions that are established. But it is good to question and validate data as we'll.

    Keep up the good work Wade.

    In solidarity,

    Skandic
     

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