# SV safety



## jbo_c (Dec 17, 2020)

Why is it safe to cook foods sv at, say, 130 for x(or even xx) hours without cure?  Meat in a vac seal bag below 140 seems like a great c. Botulinum play place.  We make a big deal about cold smoking and using cure, but not SV and cure even though the environmental conditions are generally similar as far as the organism is concerned - low oxygen, high moisture, 60F-139F.  But it’s safe?

I know it is, but why?

   Jbo


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## thirdeye (Dec 17, 2020)

In a  short answer,   sous vide is safe because for example,  you keep bagged meat in a 130° water bath* until enough bacteria have been killed *(and sometimes, longer times are used for tenderness, like a corned beef)*. *A number of pasteurization charts allow you to select a temperature and a time based on food type and thickness.  Check out this extensive guide by Doug Baldwin.


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## chef jimmyj (Dec 17, 2020)

Clostridium Botulinum grows between 37.4°F (3C) and 118 4°F (48C). Beyond these temps there is insignificant of No Growth!





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						Clostridium botulinum
					

Clostridium botulinum




					food.unl.edu
				




Even though SV is Oxygen free, the Water Temp is maintained at the Long Time / Low Temp, Pasteurization Temps. Add that the Circulating Water transfersports the Heat quickly, and no bacteria has time to grow...JJ


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## indaswamp (Dec 17, 2020)

chef jimmyj said:


> Clostridium Botulinum grows between 37.4°F (3C) and 118 4°F (48C). Beyond these temps there is insignificant of No Growth!


good to know... I'm sure I've seen this in one of the Marianski books, but thanks for posting it.


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## mike243 (Dec 18, 2020)

I have seen some funky colors of meat done at about 130 for many hours, done some steaks for 3-4 hours that started to have some green tint, was dead on on temps the whole time and  vac sealed good. I see folks doing 40-50 hour roast cooks  that I want to try but haven't gotten brave enuff yet lol


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## SmokinAl (Dec 18, 2020)

mike243 said:


> I have seen some funky colors of meat done at about 130 for many hours, done some steaks for 3-4 hours that started to have some green tint, was dead on on temps the whole time and  vac sealed good. I see folks doing 40-50 hour roast cooks  that I want to try but haven't gotten brave enuff yet lol



I was skeptical at first too, but SV is safe if you follow Baldwins tables. And I might add the end product is absolutely delicious. You can take a cheap round roast & make it taste like a filet. 
Al


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## indaswamp (Dec 18, 2020)

mike243 said:


> I have seen some funky colors of meat done at about 130 for many hours, done some steaks for 3-4 hours that started to have some green tint, was dead on on temps the whole time and  vac sealed good. I see folks doing 40-50 hour roast cooks  that I want to try but haven't gotten brave enuff yet lol


For long cooks, it is a good practice to blanche the sealed bag( with the meat in it) in 180*F water for about 4-5 minutes prior to placing it in the sous vide bath @130*F. This will pasteurize the inside of the bag for the long cooking process. Some fermentation bacteria can thrive at those high temps and cause some funky smells and colors. There is even one that will make the green color by consuming Hydrogen Peroxide....


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## Bearcarver (Dec 18, 2020)

mike243 said:


> I have seen some funky colors of meat done at about 130 for many hours, done some steaks for 3-4 hours that started to have some green tint, was dead on on temps the whole time and  vac sealed good. I see folks doing 40-50 hour roast cooks  that I want to try but haven't gotten brave enuff yet lol




Do it at 131°, or above.

Bear


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## Inscrutable (Dec 19, 2020)

What JJ and Bear said.
Also, I only do solid cuts of meat, so the surface bacteria see the requisite temps quickly. I never use ground or rolled where you can hide bacteria internally a long time before reaching pasteurization temps. They will eventually die, but can leave byproduct/toxins behind.
Follow the rules (Baldwins bible is great) and you are fine, and as Al said treated to some wonderful tastes/textures on cheaper tougher cuts.


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