www.sausagemaking.org

Dear All,

I am really quite confused now. I thought I had a pretty good understanding of method 2. As I see it the equation is telling us about ppm of the brine and meat as a unit (hence adding them together) at equilibrium and nothing else. You have to then work out the actual amount of nitrite in the meat from the ppm.

NCPauls recipe contains 1200g meat and 600g brine with 1g nitrite added.
so the calculation goes

1 x 1000,000/1200 + 600 = 555.5 ppm

this is 555.5 mg/kg distributed through the brine and meat
so in the brine you have

555.5 mg/kg x 0.6 kg = 333.3 mg nitrite

and in the meat you have

555.5 mg/kg x 1.2 kg = 666.6 mg nitrite

This 2:1 ratio reflects the 2:1 ratio of the recipe
If he was using 500 mg meat the calculation would be

1 x 1000,000/500 + 600 = 909 ppm

Again distributed though the meat and brine

909 mg/kg x 0.5 kg = 454.5 mg nitrite in the meat

909 mg/kg x 0.6 kg = 545.6 mg nitrite in the brine

This too reflects the ratio of meat to brine

I don't see where the problem with this is. It doesn't tell us anything about the percentage of water in the meat but I am not at all sure that it needs to. It also tells us nothing about time because it is assumimg that equilibrium will be reached and that experienced curers know how long this will take.

It seems to me that this calculation can be used for any size of meat as long as you are prepared to leave it in the brine until it reaches equilibrium.

I may be missing something crucial so please let me know...

Jane

Dear Oddley,
I am new to this forum and have been on it recently because I have been trying to get to grips with how to use nitrite and nitrate safely. My original question was asking for sources of information and this recent discussion was a spin off from that. Wheels kindly pointed me in the direction of the FDA document and on reading it I thought I understood how to use the method 2 calculation. I really struggled to understand method 1 as I cannot get my head around what pickup actually means.

You have obviously all been debating these things for years and have developed knowledge and practices from these discussions and from experience that I, as a newcomer, am unaware of. I need to clarify basic assumptions and go over ground that you have probably covered many times over. I am sorry if I appear stupid or to have totally missed the point - I am just trying to learn and understand. Would you please let me know if my understanding of the basic method 2 calculation is wrong?
Best wishes,
Jane

Oddley wrote:

jane wrote:Dear All,

I am really quite confused now. I thought I had a pretty good understanding of method 2. As I see it the equation is telling us about ppm of the brine and meat as a unit (hence adding them together) at equilibrium and nothing else. You have to then work out the actual amount of nitrite in the meat from the ppm.

NCPauls recipe contains 1200g meat and 600g brine with 1g nitrite added.
so the calculation goes

1 x 1000,000/1200 + 600 = 555.5 ppm

this is 555.5 mg/kg distributed through the brine and meat
so in the brine you have

555.5 mg/kg x 0.6 kg = 333.3 mg nitrite

and in the meat you have

555.5 mg/kg x 1.2 kg = 666.6 mg nitrite

This 2:1 ratio reflects the 2:1 ratio of the recipe
If he was using 500 mg meat the calculation would be

1 x 1000,000/500 + 600 = 909 ppm

Again distributed though the meat and brine

909 mg/kg x 0.5 kg = 454.5 mg nitrite in the meat

909 mg/kg x 0.6 kg = 545.6 mg nitrite in the brine

This too reflects the ratio of meat to brine

I don't see where the problem with this is. It doesn't tell us anything about the percentage of water in the meat but I am not at all sure that it needs to. It also tells us nothing about time because it is assumimg that equilibrium will be reached and that experienced curers know how long this will take.

It seems to me that this calculation can be used for any size of meat as long as you are prepared to leave it in the brine until it reaches equilibrium.

I may be missing something crucial so please let me know...

Jane

The above method is perfectly fine. You obviously have a grasp of this particular formula.

I never use method 1 as in pickup, as I never know how much it will pick up. I personally, only use it for calculating pumped meat, there you know exactly how much it's going to pickup, apart from drip of course.

(This software is a nightmare , I've stitched everything as best I can)

Dave

Jane
There is nothing wrong with your calculations .

Jim

That is relief!
Thank you

Can I check my understanding of the term 'pickup' in method 1?

Charles (my rather more scientifically minded boyfriend) argues that when meat is put in to a brine solution there is an early and rapid pickup of water (carrying with it by a process called 'solute drag' salts in the solution). He says that this is not a diffusive process but a 'mechanical' one. He now (after some arguments) thinks that this happens in a matter of hours and not days and that this is the 'pickup' referred to by the FDA. He calls this a 'mass movement'.

He says that the salts change the nature of the meat proteins and that over a much longer period of time diffusion of solutes takes place and as this occurs there is a gradual loss of water (and therefore of weight) from the meat.

Is this understanding of the physical process right?

Jane

Jane - The mental image I use is wet sponge put into a bucket of salt water. The salts ions will diffuse into the water in the sponge, faster if the brine is more concentrated. Commerical producers can squeeze the sponge before they put it into the bucket.

Dear Oddley,

Solute drag is a term used in dialysis where solutes are carried with water as it crosses a semi-permeble membrane (so long as they are small enough to get through the holes in the membrane). It is also called convection. It would only be relevant to curing if there were that mass movement of water -which as you say may be artificially created in commercial settings..

I will be feeding Charles plenty of fish to help the grey matter along.

Jane

Oddley if there is any merit in Janes theory then you wouldnt necessarily need a high pickup.
6 kgs of meat to cure to 150ppm would need to pick up 0.9 gms nitrite
If we were to suppose a pick up of 2% it would pick up 120 gms brine,which of necessity contain 0.9 gms nitrite which would mean 1000 gms of brine would contain 7.5 gms nitrite.Granted it would need some standing time and time is money.
Jane Is it your contention that at a very early stage in the process there is so as to speak an early rush of water along with its soluables.into the meat Any thought as to how much and what happens to the soluables after. Leaving aside water we know that equillibrium will be reached in say 10 days so are you suggesting that the road to equillibrium is not a straight line.
I think that before we finish Charles may need some chips and a glass of something with his fish

Oddley you said

What is important is that we understand is that method 1 calcs are based on pickup/pump at the beginning of the cure,so the meat can be weighed,for verification of ingoing amounts.

I can appreciate that you would weigh immediately after a pump to verify ingoing amounts,but Im at a loss as to assertain when you should weigh after an immersion to verify ingoing amounts.

Jim

[/quote][/i]

Oddley
Its got to be calculated? Do you mean when? i.e time.

Jim