Smell from sous vide, normal?

What temperature are you doing the beef cheeks at? Normally a bad smell is a sign that something is wrong but I'm surprised it's getting out of the bag. Is the water in the machine still clear? Sometimes if there's a leak in the bag the juices will come out and cook, but that normally smells more like a weak stew.

Thank you for your reply.

I am cooking at 57 degrees celsius (134,6 degrees Fahrenheit).

The water is still clear.

The smell is not horrible, but is not delicous either. It is ´hard to descrige, English not being my native language. As I wrote in my previous post, the smell is something like dog food

Were the cheeks vacuum packed by you, or were they bought vacuum packed?

If bought vacuum packed, my thought would be that there was perhaps some blood on the outside of the packaging, which could be what you're smelling.

Thank you for your reply. I did vacuum pack them myself. On one of the cheeks there was a spot that looked to me as if it was coagulated blood, not much, perhaps the size of two peas. I was not sure what it was, I did not cut it off. But anyway, it was inside of the bag.

To do something, I took out the cheeks and emptied the bags and washed the cheeks in running cold water for a couple of seconds. I cleaned the bags and put in the cheeks again. I believe that the smell is not quite as strong as before.

I am using Ziplock bags and water pressure to create a "vacuum".

By the way, the cheeks have been in the water for 24 hours. They still felt hard, not very tender.

Blood inside shouldn't be giving you a smell outside. I was more thinking if they had been 'stacked' at the butchers with some unpackaged meat.

I've not cooked cheeks, but I think you'll be needing 48-72 hours.

Are the ziploc bags 'boil safe'? Some bags designed for freezing do degrade when heated - although from my experience most cope with 57 degrees.

I believe that the Zíplocks will stand 57 degrees C (134,6 F), but I do not have any guarantees.

The smell is not that much of burnt plastic, more of dog food.

I think you're probably right, but it was another option to explore. If the plastic won't stand the temperature, often the result is that the bag becomes permeable and releases some of the contents into the water.

Is the heating vessel you're using also used for cooking food (ie. something like a crockpot), or is it a dedicated water bath?