Salt to meat %

[Portly]

I have a couple of questions in regards to salt % which I would be grateful if anyone could clarify.

1 In curing salami, is there a minimum amount of salt needed to produce a safe product? I have read a minimum 2.5% is advised on the Len Poli website, but have found most recipes add less than this amount.

2 When making Air dried products from whole muscles e.g coppa, ham etc, what is the salt to meat ratio? I see that Len Poli states 4.5% salt to meat, but have again found a lot of variety in recipes. I am looking to use the salt/cure as a rub rather than covering it in the cure as I suppose this would more evenly distribute the cure ingredients

Appreciate any help on this. Thanks.

[Oddley]

It is all to do with water activity. These quotes are both from the FSIS

Salt
For example, salt has been used to preserve meat products (i.e., salt-cured meats). Salt, which lowers the aw, is often supplemented with other ingredients, such as nitrites, that aid in spoilage prevention. In all cases the salt is necessary to inhibit the growth of sporeforming bacteria, such as C. botulinum, and only enough heat is applied to kill the non-heat resistant vegetative cells. Strains of C. botulinum that grow in a suitable food containing 7 percent salt are known. For example, toxin was produced in experimentally produced turkey frankfurters with an aw of 0.956 (7% NaCl) in 12 days at 27�C (81�F). The growth of these strains, however, is inhibited at a concentration of 10 percent, which is equivalent to a water activity of 0.935, when all other conditions are optimum. If conditions are not optimum for growth (e.g., low pH or temperature) then less NaCl is required to inhibit growth. For example, growth of C. botulinum may occur at an aw of 0.96 (6.5% NaCl) at pH 7.0, but if the pH is reduced to 5.3, growth will be inhibited at an aw of 0.97 (5% NaCl). The actual salt content of a meat product is not as important in inhibiting C. botulinum as the brine concentration (percent of salt in the aqueous portion of the meat). Toxin production is inhibited at a brine level exceeding 9.0%.

After the salting stage, the product enters the “burning” stage. At this stage the product is held at low temperatures (<40�F (4.4�C)) for many days to allow for sufficient salt penetration and equilibration. The goal is to eventually lower the water activity sufficiently to inhibit microorganisms to a point at which the temperature can be elevated. This period often takes many weeks to achieve uniform salt distribution to greater than 4.5% with a water activity below 0.96. Excess surface salt may be removed during this period and only moderate air circulation is desired to avoid surface drying. Some processors may apply a soft fat to the cut surface of the lean tissue to avoid this drying.

[dougal]

Hello Portly ! Welcome !

I have a couple of questions in regards to salt % which I would be grateful if anyone could clarify.

1 In curing salami, is there a minimum amount of salt needed to produce a safe product? I have read a minimum 2.5% is advised on the Len Poli website, but have found most recipes add less than this amount.

Ah, but the salt you *add* is only part of the story.
Not least, you are also going to take away *water*.
Hence the final product is going to have a higher salt proportion than the starting ingredients.

I don't think its helpful to look for an exact boundary between safe and unsafe, let alone for an ingredient such as salt that plays a multiplicity of roles.
As to whether there is an officially recommended minimum final salt proportion (NaCl by weight, as per a recipe) - I don't know !! But, as such, its going to be an arbitrary level, for commercial products, with a margin for error, rather than marking an exact specific biochemical threshold. And so, it wouldn't surprise me if different authorities were to set different levels, further adding to the confusion!
One means of taking into account all the various things dissolved in the water is the concept of "water activity". For a solid, this is in some ways analagous to the concept of atmospheric relative humidity. (But its not something I have any great understanding of.) In food processing, its a measure of the wetness/dryness of the product. More stuff dissolved makes it behave as though it was dryer. Its a way of putting numbers on this.

2 When making Air dried products from whole muscles e.g coppa, ham etc, what is the salt to meat ratio? I see that Len Poli states 4.5% salt to meat, but have again found a lot of variety in recipes. I am looking to use the salt/cure as a rub rather than covering it in the cure as I suppose this would more evenly distribute the cure ingredients

When you put solid salt on the outside of a piece of meat, water is taken up by the salt, drying the flesh it is in contact with. The water within the meat would tend to spread evenly, and so will try and restore the hydration of that which the salt has dried. Thus water is 'sucked' out of the meat.
BUT, that water will be tending to dissolve the salt - forming a strong brine. That liquid, in contact with the meat surface will allow the meat to take up some salt (or rather sodium and chloride ions).
How much salt might actually be taken up is going to depend on many factors, like whether the meat is allowed to sit in a puddle of brine.

I know that's not an answer to your second question as to the amount of salt to use as a rub - but I hope it explains why I think that there is no simple universal answer - at least not outside the context of a specific process recipe.

You will note that Oddley's second quote above indicates that a final salt content of "4.5%" is being advocated. HOWEVER, with salami, we can control and measure what goes in. With whole muscle meats we have no means of measuring what has actually been taken up as a dry cure (apart from our tastebuds).
The "4.5%" indicated by the US Food Safety and Inspection Services is in the context of a final content - and whatever else it means, it is *not* an indication of the amount to apply as a rub.

There is a further layer of confusion to be aware of

... Strains of C. botulinum that grow in a suitable food containing 7 percent salt are known. ... The growth of these strains, however, is inhibited at a concentration of 10 percent ...

What, exactly does that "7 percent salt" (or 10 percent) really mean?
And how does it relate to the "salt to meat ratio" that you asked about?

It is usually recognised that about 10% sodium chloride (calculated as per cent brine concentration) is necessary to inhibit growth and toxin production of C Botulinum type A and proteolytic type B. In contrast, type E growth is inhibited by a brine concentration of about 5%. Type C appears to be even less salt-tolerant than type E, its growth being inhibited by 3% salt.

http://www.pubmedcentral.gov/articleren ... tid=376479 see bottom of page 1028
They are talking about percentages of saturated brine (ie 10% saturated brine + 90% water is plenty) and *not* percentage by weight of solid crystalline salt.
And this in the water inside the meat. Its not referenced to the total weight of meat! Beware!

Follow trusted recipes, and always beware of thinking that you understand what a writer probably means...

[Oddley]

I suppose I'm slightly at odd's with dougal as there are recommended levels of salt in a Brine concentration. Also if a salt rub is applied to muscle meat I would expect over the course of time all the salt to be absorbed by osmotic pressure and thereafter equalization in the meat.

The recommended salt in a brine concentration to kill most bacteria is >10%. A brine concentration can be calculated by.

Brine concentration% = Salt/(Moisture + Salt)*100

The problem with the above calc is we don't know the exact water content or salt content of a cure rubbed piece of meat. Commercially they take samples and have them analysed. But we can get a ball park figure as we know the ingoing salt and also, all meat contains between 65-80% water.

The use of salt in water activity is, salt will bind bulk water making it unavailable for bacteria to use. keeping this in mind an Aw of < 0.85 will also kill most bacteria. Aw can be calculated by

Aw = Humidity / 100

Where humidity is found by enclosing the product in a container and when humidity is equalized taking a reading.

Then for salami we have ph, a ph of <4.6 will kill most bacteria.

As suggested by my previous post not all the above have to be implemented to the extreme we can use a method called the Hurdle method this is using combinations of the above to cause a hostile environment for bacteria.

[Portly]

Oddley/Dougal,

Thanks for the info and quotes and my apologies for the delay in acknowledging them.
I agree that the �hurdle� method is the safest and easiest way to progress. I can test my salamis Ph and Aw during/after the incubation and curing process and also have good control over the addition of ingredients so shall play around a bit there. However I shall make some small bore salamis for this so it should not take to much waiting unlike the air dried ham. I asked the questions about the rubs as I have an awful lot of Cure 2 (6.25%nitrites 4% nitrates 89.75 salt) at hand and wanted to utilise this for making air dried ham rather than having to buy the cure mix. I have found so much variation in recipes that I can not really determine which is a reliable one over another, which is probably further indication of there being no hard and fast rule.

Would you or anyone else have any tested cure ratios or suggestions for this for this?

I appreciate your help guys and hope I am not asking obviously unanswerable questions. It is all a bit of a learning curve. Cheers.

[Portly]

Oddley/Dougal,

Thanks for the info and quotes and my apologies for the delay in acknowledging them.
I agree that the �hurdle� method is the safest and easiest way to progress. I can test my salamis Ph and Aw during/after the incubation and curing process and also have good control over the addition of ingredients so shall play around a bit there. However I shall make some small bore salamis for this so it should not take to much waiting unlike the air dried ham. I asked the questions about the rubs as I have an awful lot of Cure 2 (6.25%nitrites 4% nitrates 89.75 salt) at hand and wanted to utilise this for making air dried ham rather than having to buy the cure mix. I have found so much variation in recipes that I can not really determine which is a reliable one over another, which is probably further indication of there being no hard and fast rule.

Would you or anyone else have any tested cure ratios or suggestions for this for this?

I appreciate your help guys and hope I am not asking obviously unanswerable questions. It is all a bit of a learning curve. Cheers.

[Portly]

sorry not sure what happened there. Serious case of over clicking no doubt!

[Oddley]

To be honest I wouldn't recommend using cure #2 for air dried hams.

You can of course use it for salami I would suggest at the rate of:

3.2 gm/kg meat This will give an ingoing amount of 200 mg/kg sodium nitrite 128 mg/kg sodium nitrate.

If you really want to use it for air dried hams a air drying from about 3 months upwards I think the amount to use would be:

4.8 gm/kg meat This will give an ingoing amount of 300 mg/kg sodium nitrite 192 mg/kg sodium nitrate.

For small pieces of air dried ham use the 3.2 gm/kg.

If I were air drying a large ham I would use 200 mg/kg sodium nitrite and 700 mg/kg potassium nitrate.

[Portly]

Thanks. I have been working on 156ppm for salami meaning the addition of 2.5gm/kg cure2. Will these be safe to eat and is 200ppm the UK safe value?
I have really been following guidelines in books, which admitidley are mostly from the US. They state the recomended nitrite levels as 156ppm for comminuted products and 625ppm for dry dured(nitrite ingoing using cure 2) which amount to a frightneing 10gm/kg. Can this be right?

I would be very keen to learn how you determined the amounts for the cure 2 ingoing for the airdried ham and also how you determined your own cure combo. I have been reading about your preference for adding seperate Nitrites and nitrates with interest.

Just to avoid misunderstanding, I am not wanting to question your calcs, just very keen to learn how one would go about determining them. I am not hugely mathmatically minded but can hold my own when I understand something so would be keen to see how the process works and maybe try to formulate some spreadsheets to make my life easier and possibly safer!

Thanks alot for your time so far.

[Oddley]

Thanks. I have been working on 156ppm for salami meaning the addition of 2.5gm/kg cure2. Will these be safe to eat and is 200ppm the UK safe value?

I should think it is safe, remember the hurdle concept so if you have added a starter culture this will be only one of the safeguards. I would normally add 200 ppm nitrite not for the nitrite content but to up the nitrate content which is the reservoir for nitrite. That's why I'm not keen on cure #2 you have to use what's given instead of choosing.

FSA regulations on additives (Nitrates and nitrites).

http://www.opsi.gov.uk/si/si1995/Uksi_19953187_en_4.htm

I have really been following guidelines in books, which admitidley are mostly from the US. They state the recommended nitrite levels as 156ppm for comminuted products and 625ppm for dry dured(nitrite ingoing using cure 2) which amount to a frightneing 10gm/kg. Can this be right?

The 156ppm for comminuted product I find reasonable. The 625ppm I personally would not use. With that much ingoing and the fact that some nitrite will convert to nitrate to start the whole process of conversion off again. As nobody can predict the conversions with any accuracy this just seems too much. what we do know is that the nitrite will in most cases over the course of time have a residue of between 10-20% this means you will have an amount of free nitrite left between those two amounts.

I would be very keen to learn how you determined the amounts for the cure 2 ingoing for the airdried ham and also how you determined your own cure combo. I have been reading about your preference for adding separate Nitrites and nitrates with interest.

The basic formula can be found here:
http://www.extension.umn.edu/distributi ... J0974.html

Dry cure, with a premixed salt based cure, my formula:

------------grams premixed cure * % Nitrite in mix * 1000000
PPM = -----------------------------------------------------------------
------------------------100 * Weight of Meat

My extended formulas can be found here:
http://forum.sausagemaking.org/viewtopic.php?t=1116

I determine my own cures by knowing that 120 ppm of nitrite is the optimum amount for bacteria control, and that nitrite is a very reactive chemical, then estimating the amount of nitrate that will keep the nitrite at this level for the cure period and the first part of drying time. This is mostly experience based on reading so much. I know from the FDA that for Black forest ham the ingoing amount of nitrates are 200 ppm nitrite 700 ppm potassium nitrate. I expect them to know more than I do, So if it's good enough for them it's good enough for me.

As you can understand this is a big subject. One I have been studying for 18 months now and I'm still learning. If you want to extend your knowledge have a look at my conversations with Parson snows on this forum.

[Portly]

It is a huge topic and not one I expect to learn about overnight. I think it is time I sat down and worked a few things out now with the information you have given me. when I have things clearer and down on paper, would you mind checking them over for mistakes? Might be some time.....

I do a few realted questions if you have the time.

1, back to the salt question. Using either of the cures you mentioned for the Air Dried ham, what quantity of salt would you use/Kg of meat?

2, A bit of a thikko question here.....I just want to check that the cure weight is for the combined meat/fat weight?

3, Any chance of a copy of your brine calculator from the links you posted for me?

4, Is residual NitrATE an issue?

Thanks again for making a steep learning curve slightly flatter!

[Oddley]

1, back to the salt question. Using either of the cures you mentioned for the Air Dried ham, what quantity of salt would you use/Kg of meat?

3.5% Brine concentration will inhibit most of the bad bacteria. So a suggested ingoing amount of salt would be 3.3 % of meat weight.

2, A bit of a thikko question here.....I just want to check that the cure weight is for the combined meat/fat weight?

Another good question. Fat has normally only a few % of water (can't remember exactly how much atm) so it is pretty insoluble. I calculate on the estimated meat weight plus 10% of the fat weight.

3, Any chance of a copy of your brine calculator from the links you posted for me?

For you and anybody else who wants it:

CLICK HERE

4, Is residual NitrATE an issue?

Yes it is, but it is nowhere near as toxic as nitrite.

[Portly]

Do your meat/fat proportions i.e cure%=meat+10% fat weight stand for both air dried ham and salami/cured sausages?

Should one have made a small batch of salamis using the combined meat/fat weight (70 meat 30 fat) to work out the Cure% Will they be safe to eat? I was reckoning they should be ready after a total of between 15-20 days hanging time.

The moment I made this batch I though about this question. oh well 20/20 hindsight would be a great thing.

[Oddley]

Do your meat/fat proportions i.e cure%=meat+10% fat weight stand for both air dried ham and salami/cured sausages?

My calc would be:
------------------------------------------------------Percent of fat * weight of Fat
Calculatable product = Meat only weight + -----------------------------------
------------------------------------------------------------------100

Example: With a 1 kg piece of pork 70% vl
------------------------------------------------10 * 300
Calculatable product = 700 + ----------------------------------- = 730 gm
---------------------------------------------------100

So you would calculate the cure on 730 gm meat.

Yes. This is a tricky subject as opinion is split on this subject. Some people like to include all meat/fat in their calcs, some don't. After reading a bit more, you will have to make up your own mind.

Should one have made a small batch of salamis using the combined meat/fat weight (70 meat 30 fat) to work out the Cure% Will they be safe to eat? I was reckoning they should be ready after a total of between 15-20 days hanging time.

I don't really understand what you are saying here. But if your salami's have lost > 30% of their green weight they should be ok to eat.

BTW redownload the brine calculator as I have just added some error handling.

[Portly]

Sorry. What I meant was as I added cure 2 to the total meat fat ratio rather than the meat+10% ratio, would they be safe for consumption due to the extra cure added.
I am hanging them for between 15-20 days till they have lost 30% weight so guess that should a) be enough time for the cure to dissapate and b) as I was working to 156ppm guess they would still be within the safe limits anyway.

Probably clear as mud now and I think I may have answered my own question unless you dissagree.

Thanks for the brine calc update. I shall leave you in peace now until the next question.