Sodium Nitrite

Discussion in 'Food Safety' started by jazzy, Sep 20, 2011.

  1. jazzy

    jazzy Newbie

    I'm doing hot smoked salmon and going to give to lots of friends and family and possibly start a small mail-order business if things go well.  I've been reading and reading about food safety and the use of Sodium Nitrite to inhibit Botulism toxin.

    What is interesting is that most of the commercial smoked salmon makers that produce a vacuum sealed product, do NOT use Sodium Nitrite in their brine/cure.  Instead there is just a note on the label 'Must be stored below 40F' or something to that effect.

    The likelihood of Botulism toxin developing is quite low, but if it ever did develop, it could kill someone.  This would be risky to a business which makes me wonder why few use it?  Is it because based on history they've never had a problem so then in the unlikely event they just use liability insurance to protect their business?  Of course if it says refrigerate below 40F and the person didn't, then its not the makers fault.  But what if there is a delay in shipment even when the shipment had ice packs and it is a hot summer?

    Sodium Nitrite is considered safe.  It is toxic but the amount used to cure meats is very small.  There is evidence it can break down over time into products that have shown to be carcinogens for lab animals.  A lot of people these days that are health-conscious avoid any products with Nitrites or Nitrates in them.  You see at the grocery store, nitrate-free hot dogs, uncured bacon, etc.  These products would probably have the same if not higher possibility of botulism than smoked salmon. 

    Further research says that it takes 7 days at room temp for botulism to develop in smoked salmon and this is when they injected the spores in it purposely.  At 50F it takes weeks.

    Yet I talked to a lady that has been running a small commercial smokehouse business for 45 years and she uses prague powder #1 in her dry brine at a rate of about 15% prague powder to 85% normal pickling salt.  The brine it about 2.5 parts of salt/prague to 1 part sugars.  So she's using about 10% prague powder in the dry mix, at 6.25% Sodium nitrite, that means there's about 0.6% sodium nitrite in her dry brine.  For meats, the ratio is 4 ounces per 100 lbs of meat, but I believe that is for actually mixing the stuff into the meat (like sausage) ?

    This is a somewhat technical subject but this forum has been around a long time.  There must be people here with knowledge/experience regarding use of Sodium Nitrite.  I'd love to hear your perspective.
  2. pops6927

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

    Are you talking about dry-curing or wet brining?
  3. alblancher

    alblancher Master of the Pit Group Lead OTBS Member

    If you are going to be offering the product for sale you will fall under a whole set of rules to ensure the public's safety.  In addition to the label saying to keep the product below 40 degrees was there also an expiration date?  You may want to look up the food safety codes, try to find one that addresses your specific application.  They also outline a procedure to have your method reviewed by the governing agency.  I have looked at several methods for smoking fish and most do not require the use of cure.  The fish is brined and then smoked.  I wish I could offer a definitive answer but like you I have read different opinions and I am not comfortable with anything I have read.
  4. jazzy

    jazzy Newbie

    Well I emailed a local commercial smoker who I know does not use Sodium Nitrite.  It is not required by the FDA.  The guidelines are a minimum 3.5% Water Phase Salt level.  Nitrite is essentially an option if you want to reduce the amount of salt in the finish.  Although Sodium Nitrite is a salt itself so I'm not sure how much different the finished product would be.

    From the FDA:
    • Control Strategy Example 1 - Smoking

    For controlling toxin formation by cold smoking:

    Critical Limit: The smoker temperature must not exceed 90°F (32.2°C).

    For controlling toxin formation by hot smoking:

    Critical Limit:
    The internal temperature of the fish must be maintained at or above 145°F (62.8°C) throughout the fish for at least 30 minutes.

    For controlling toxin formation by brining, dry salting, and/or drying:

    Critical Limit: The minimum or maximum values for the critical factors of the brining/dry salting, and/or drying processes established by a scientific study. The critical factors are those that are necessary to assure that the finished product has:
    • For refrigerated, reduced oxygen packaged (e.g. vacuum or modified atmosphere packaged) smoked fish or smoke-flavored fish, not less than 3.5 percent water phase salt, or, where permitted, the combination of 3.0 percent water phase salt and not less than 100 ppm nitrite.
  5. danmcg

    danmcg Master of the Pit OTBS Member SMF Premier Member

    Never done fish or even looked at a recipe. but I guess if it's brined with a heavy enough concentration of salt to give it a 3.5 level of salt in the finished product and also smoked it should be safe and not need the nitrite. I guess it would also be good to know the amount of moisture that you loose during smoking and drying as this will lower the water activity and give you a longer shelf life.

    Do you add a sugar to the brine also? 3.5 % is salty.
    Last edited: Sep 20, 2011
  6. danmcg

    danmcg Master of the Pit OTBS Member SMF Premier Member

    Ya got me interested so I was pockin around the NYS rules and reg's and found this,
    1. processed fish that have a water phase salt level of at least 17 percent shall not require refrigerated storage; and
    2. processed fish which contain a water phase salt level of at least 10 percent, a water activity of less than .85, or a pH of 4.6 or lower may be distributed or sold at refrigerated temperatures that do not exceed 45 degrees Fahrenheit.
    Here's a link to it if you're lookin for more info, I;d bet it's the same as the fed reg's.

    Anyone remember blind robins? They were dried brined herring that were sold in bars as a snack. Like chewing on a salt lick. They had to be the 17% they mention in #1
    Last edited: Sep 21, 2011
  7. xtian

    xtian Newbie

    A little late to the party, but I just read and wanted to comment to clarify some things here. 

    Cold smoking has more safety issues than hot smoking. Its a low-oxygen environment where Clostridium botulinum - a life threatening bacteria - can form. The heat from a hot smoker would kill any Clostridium botulinum, so its not an issue. The second is you are holding protein in "the danger zone" 40F - 140F for an extended period of time where all kinds of bacteria can grow to harmful levels.

    Pink salt #1 (6.25% sodium nitrite), is added to cold smoked items like ham and bacon to inhibit growth of Clostridium botulinum. Contrary to a lot of misinformation, it does not add any flavor and is not harmful to humans at the recommended amounts. Outside of the distinctive pink coloring it gives to meat, it is physically undetectable.

    There are a number of ways to kill pathogens and parasites without cooking.  Clostridium botulinum is killed at -7C for 10 days. Commercial processors of cold smoked salmon, who do not use nitrites, could be deep-freezing their product. This bacteria is also killed by high enough levels of acidity and salt.

    Sorry for the lack of references here, but there's plenty of FDA and institutional documentation out there. 
  8. wade

    wade Master of the Pit OTBS Member SMF Premier Member

    Cold smoking is not a low oxygen environment as it is important to maintain a good air flow through the smoker during the smoking process. You could argue that the oxygen levels are slightly reduced as the dust/pellets smoulder to produce the smoke however this will not use significant amounts of the oxygen in the air moving through the smoker. Many commercial smokers do not actually burn wood to produce smoke - they use friction.

    The relative dangers will depend on what you are smoking...

    If you are hot smoking a lump of meat then yes the temperatures in the smoker will kill off any bacteria/spores that are on the surface, however if the meat has been boned, rolled or even injected then some bacteria/spores will have been taken into the meat and will remain at a much lower temperature. Most will be killed by the time the meat is cooked however hardy spores (like Botulinum) will survive.

    Depending on what you are cold smoking and how it is subsequently stored then bacteria and spores are more or less of a risk. For example, when dry curing bacon or fish then the initial salt in the dry brine will inhibit the growth or kill any surface bacteria. The salt draws out water from the meat/fish which then also inhibits bacterial growth. The smoking of the fish then removed more water which inhibits growth further. When producing traditional smoked salmon Botulinum is not an issue as under ideal conditions it takes 10+ days for spores to produce sufficient levels toxin to start to cause illness and longer when refrigerated. This is why the commercial shelf life of traditional smoked salmon (and other similar foods) is usually 10 days under refrigeration.
  9. nepas

    nepas Smoking Guru Staff Member Moderator Group Lead OTBS Member

    Cold smoking is not rocket science.

    CURES - Cures are used in sausage products for color and flavor development as well as retarding the development of bacteria in the low temperature environment of smoked meats.

    Salt and sugar both cure meat by osmosis. In addition to drawing the water from the food, they dehydrate and kill the bacteria that make food spoil. In general, though, use of the word "cure" refers to processing the meat with either sodium nitrite or sodium nitrate.

    The primary and most important reason to use cures is to prevent BOTULISM POISONING (Food poisoning). It is very important that any kind of meat or sausage that will be cooked and smoked at low temperature be cured. To trigger botulism poisoning, the requirements are quite simple - lack of oxygen, the presence of moisture, and temperatures in range of 40-140° F. When smoking meats, the heat and smoke eliminates the oxygen. The meats have moisture and are traditionally smoked and cooked in the low ranges of 90 to 185° F. As you can see, these are ideal conditions for food poisoning if you don't use cures. There are two types of commercially used cures.

    Prague Powder #1

    Also called Insta-Cure and Modern Cure. Cures are used to prevent meats from spoiling when being cooked or smoked at low temperatures (under 200 degrees F). This cure is 1 part sodium nitrite (6.25%) and 16 parts salt (93.75%) and are combined and crystallized to assure even distribution. As the meat temperate rises during processing, the sodium nitrite changes to nitric oxide and starts to ‘gas out’ at about 130 degrees F. After the smoking /cooking process is complete only about 10-20% of the original nitrite remains. As the product is stored and later reheated for consumption, the decline of nitrite continues. 4 ounces of Prague powder #1 is required to cure 100 lbs of meat. A more typical measurement for home use is 1 level tsp per 5 lbs of meat. Mix with cold water, then mix into meat like you would mix seasonings into meat.

    Prague Powder #2

    Used to dry-cure products. Prague powder #2 is a mixture of 1 part sodium nitrite, .64 parts sodium nitrate and 16 parts salt. (1 oz. of sodium nitrite with .64 oz. of sodium nitrate to each lb. of salt.) It is primarily used in dry-curing Use with products that do not require cooking, smoking, or refrigeration. This cure, which is sodium nitrate, acts like a time release, slowly breaking down into sodium nitrite, then into nitric oxide. This allows you to dry cure products that take much longer to cure. A cure with sodium nitrite would dissipate too quickly. Use 1 oz. of cure for 25 lbs. of meat or 1 level teaspoon of cure for 5 lbs. of meat when mixing with meat. When using a cure in a brine solution, follow a recipe.
  10. atomicsmoke

    atomicsmoke Master of the Pit OTBS Member

    Clostridium botulinum is killed at -7C for 10 days.
    Bacteria I assume. As far as I know spores are not killed by freezing. Neither is toxin (neutralized) if already formed.

    Cold smoking being a low oxygen environment is one of the internet legends that everyone knows about but no one knows where it comes from.

    One more rebuttal: nitrite does change taste and texture. Can you make bacon or ham taste like they do without nitrite?
    Last edited: Mar 9, 2017
  11. wade

    wade Master of the Pit OTBS Member SMF Premier Member

    What you say above is generally true for the sausage products that you refer to however it cannot be applied to all smoking. Originally the primary reason to cure is to prevent the spoilage of meat in times of plenty that needed to be stored for eating in times of shortage. These days though the cure is often used to obtain a specific flavour and texture rather than for shelf life. Yes, Botulism is a concern when curing meats that will be stored at room temperature for periods of time however it isn't a problem for meats that will be smoked, stored chilled and then eaten quickly or frozen. For example, traditional smoked salmon is cured well above 40 F and almost no commercial producers of smoked salmon (in fact none at all that I know of) use Nitrite.

    In this forum we may use the word "Cure" to generally mean using Nitrate/Nitrite (in addition to using salt, and dehydration) but this is not the case everywhere. Many curing recipes and books out there are aimed at the general public and cure using only salt and sugar. Most "celebrity" chefs do not advocate the use of Nitrite/Nitrate in their recipes. This is probably more to avoid the possibility of litigation though should anything go wrong.

    The comment above regarding the heat and smoke eliminating oxygen in a smoking container may have some truth when hot smoking with charcoal/wood (where limiting the supply of oxygen is used to control the internal temperature of the smoker) however this would not be the case when using an electric or propane smoker. It certainly isn't the case when cold smoking either. I used to regularly scuba dive using Nitrox and so a couple of years ago I used an O2 meter to  measure the Oxygen levels going into my cold smoker and also coming out. There was less than a 5% drop.

Share This Page