7 replies to this topic

[paulkaye]

I'm going to be cooking for a population for whom food safety is of utmost importance. To get the softest, moistest meat (chicken, turkey & beef) it has been suggested that I employ sous vide. This makes a lot of sense for taste quality and should also increase safety because it prevents/limits cross-contamination after cooking. Does anyone know of key temperatures that I can use as safe minimums?

Whereas sous vide is often used to extend the life of refrigerated meats to a month or longer, I only want to use it for short-term production/storage. Something like 18 hours cooking followed by immediate inclusion of the cooked meat in another dish. Shelf life (refrigerated) of finished product is currently set at 5 days but I hope to extend to 7 days in the future. Does anyone have any comments on my intended technique/process?

Thanks,
Paul

[GMO]

I'd cook to around 80 degrees for 5 seconds if possible (that's an internal, core temperature of 80 degrees so you'd have to have a pack which would be destroyed or excellent process control to measure another temperature for that to be equivalent but remember the temperature of the sous vide packs going in will have a big impact on core temperature acheived over a given water bath temperature / time).

Equivalent temperatures would be 75 degress for 26 seconds for example, but remember this is minimum temperature and minimum holding time so just checking it for a second and seeing it's at 75 degrees would be no good.

The reason I've chosen the above temperatures would be because they are the Listeria vegetative kill temperatures which (I believe but I'm no micro bod) will also kill other vegetative bacteria but I would want to do micro on my proposed solution if I were you to be sure.

As you are not proposing to hold the product (chilled) for more than 10 days, I don't think Clostridium botulinum would be an issue, however, products which are cooked sous vide and kept for more than 10 days are cooked in a manner to reach 90 degrees core for 10 minutes to kill of Clostridium spores. Unless you have a retort, I wouldn't bother trying!

As it's for a sensitive group, I would definitely make some microbiological testing part of your design process. I also disagree that sous vide is the safest way. I would suggest the safest method of cooking would be to cook from scratch, reach a high temperature and serve immediately. Any cook / cool process can introduce a risk as you go through the micro "danger zone" more times.

That said, I'm sure it can be done safely and it's very good you're thinking of this before implementation. I'd get your HACCP team together to discuss tbh.

[Charles.C]

Dear paulkaye,

Not my product area but I do believe that as GMO indicates, your choice is typically regarded as a methodology requiring above-average attention to the risks involved.

Don't know if you are in the UK but I seem to remember the particular requirements of this class of products being discussed within the SFBB (safer food better business, free downloadable) package or perhaps the FSA recommendations for retail users available from their site.
I also seem to recall there are legal requirements regarding labelling depending on intended use by period (in the UK). But I daresay you are familiar with that already.

Rgds / Charles.C

[Simon]

Any further questions on this Paul?

[paulkaye]

I guess not. Perhaps I was subconsciously waiting for someone to tell me that sous vide was perfectly safe! Thanks for all your answers - it sounds like the general consensus is that traditional cooking methods would be safer, at least because they are more well known.
Micro testing will be implemented - I already have an independent lab on board. But it'll be more for routine monitoring, not pre-consumption testing, because time-to-consumption is less than 24 hours and testing takes at least that long.
I wouldn't say that sous vide is dead in the water but I'll put it on hold for now.
Thanks,
Paul

(p.s. Am I meant to 'close' this thread somehow?)

[Simon]

(p.s. Am I meant to 'close' this thread somehow?)

No Paul, we leave them open for future reference.

[GMO]

I guess not. Perhaps I was subconsciously waiting for someone to tell me that sous vide was perfectly safe! Thanks for all your answers - it sounds like the general consensus is that traditional cooking methods would be safer, at least because they are more well known.
Micro testing will be implemented - I already have an independent lab on board. But it'll be more for routine monitoring, not pre-consumption testing, because time-to-consumption is less than 24 hours and testing takes at least that long.
I wouldn't say that sous vide is dead in the water but I'll put it on hold for now.
Thanks,
Paul

(p.s. Am I meant to 'close' this thread somehow?)

I'd make micro testing part of your design testing rather than part of positive release (ie preconsumption) but then do some ongoing "verification" testing.

[Tony-C]

As you are not proposing to hold the product (chilled) for more than 10 days, I don't think Clostridium botulinum would be an issue, however, products which are cooked sous vide and kept for more than 10 days are cooked in a manner to reach 90 degrees core for 10 minutes to kill of Clostridium spores. Unless you have a retort, I wouldn't bother trying!

As it's for a sensitive group, I would definitely make some microbiological testing part of your design process. I also disagree that sous vide is the safest way. I would suggest the safest method of cooking would be to cook from scratch, reach a high temperature and serve immediately. Any cook / cool process can introduce a risk as you go through the micro "danger zone" more times.

Sous vide is a method of cooking that is intended to maintain and improve the integrity of ingredients by heating them for an extended period at relatively low temperatures. Some cuts of meat do benefit greatly from very long (48 to 72 hours) sous vide cooking at 55 °C. Food is cooked for a long time, sometimes well over 24 hours.

Sous-vide cooking uses airtight plastic bags placed in hot water well below boiling point (usually around 60°C).

Clostridium botulinum bacteria can grow in food in the absence of oxygen and produce the deadly botulinum toxin, so sous-vide cooking must be performed under carefully controlled conditions to avoid botulism poisoning.

Generally speaking, food that is heated and served within four hours is considered safe, while meat that is cooked for a longer period of time to tenderise it must reach a temperature of at least 55° C within four hours, and then kept there, in order to pasteurize the meat. Once pasteurized, the botulism bacteria is killed, but the possibility of botulism spores remains a concern. Which is why one would normally specify precise chilling requirements for "cook-chill", so that the botulism spores do not have the opportunity to grow or propagate.

Sous vide is used for cooking when food quality is of the utmost importance. If food safety is of the utmost importance then pasteurisation (legal requirement of 72 ° C for 15 seconds or equivalent) should be used as a minimum with rapid or blast cooling as GMO has indicated.

Regards,

Tony