When I first began cooking sous vide I was told that sous vide was a cooking method to be avoided when serving food to anyone with a compromised immune system. Since that time I’ve had a couple friends who have developed just such a problem. After reading a bit on the subject I found various suggested actions to take in order to address this safety issue.
Size the portions to facilitate quickly reaching the target temperature equilibrium.
By keeping the portion small it will heat up more quickly, reducing the amount of time it will stay in the “danger zone” where bacteria can breed. Once your food comes up to temp it will kill the bacteria present, but getting the temp above “the zone” quickly means there’s no time for toxins to be created before the bacteria is killed.
Quickly blanch or sear each item prior to bagging in order to kill any surface bacteria.
A quick dunk in boiling water, or a quick sear in a hot pan or with flame, will kill any external bacteria. When cooking for someone who is immune system compromised any action that kills germs “soonest” sounds good to me!
Cook long enough to ensure pasteurization.
This is something I always try to do anyway, but when cooking for someone whose immune system is compromised I think this is really the keystone action to take. While technically your food is “cooked” once it reaches temperature equilibrium, letting it stay in the bath until pasteurization has been reached always seems the smart thing to do in my opinion.
I wanted to make this post to share these thoughts with others in the community, and perhaps to get more others thoughts on additional actions to take or caveats I may have missed.
Does anybody see any glaring errors I’ve made or have any great suggestions to add?
I would think pasteurisation is the most important point of them all. It makes some foods accessible to those with tricky immune systems that they can’t normally eat.
No glaring errors, just also consider the importance of sufficient ice-bath chilling if a product isn’t going to be consumed right after cooking.
Sufficient refers to both time and mass of ice used. Some tumbling of products helps chilling too by moving fluids in the bags which can act as insulation. Over on the Anova FB site i have a concern for the casual approach to deep and rapid chilling and the time products can spend in the Food Danger Zone. There’s evidence of a lot of guessing replacing knowledge.
One other practice to be emphasized in serving those with a compromised immune system is the practice of maintaining a strict segregation of food raw and cooked food handling tools and surfaces to prevent contamination.
The human body is remarkably tough and capable of dealing easily with most food born hazards. A few burps and we’re over it, but unfortunately that’s not all of us.
On the FB group I have concerns about a lot of things. But I don’t get paid by Anova and have had my concerns nudged aside on occasion by some others.
Ember there are far too many people that will spew wrong information on the Internet for the sole reason “I have never gotten sick”. If the truth be known they probably have had food related illness but did not make the correlation. Then there are the few that have been lucky. As Frank said most of us have pretty resilient systems but many do not. As I age I am far more careful. When you couple lack of knowledge and food myths you really have a duo.
I fully agree Ember and John.
When hear someone say they have, “the stomach flu”, i think, “Oh yeah?”
Where do you find information about pasteurization times?
Here’s a link to Baldwin’s Practical Guide to Sous Vide http://www.douglasbaldwin.com/sous-vide.html
Pasteurization times are covered in depth by Baldwin. Best of luck.
I think one thing to remember is that pasteurization does not kill all bacteria due to the low temperatures applied, so it is extremely important to keep the food out of the temperature danger zone as quickly as possible, then stored below 4C (140F) or frozen, if possible, if not cooked and served right away.