Sous vide fans talk about how you can’t overcook your food, because it’s held at the precise temperature. That’s not entirely accurate:
It makes sense: the meat’s enzymes will start to break down the meat, making it mushy.
But that’s what happens when you overcook it by a few hours. What would happen to, say, a nice steak that was kept at 130 for a week? a month? a year? a century?
I’m guessing that normal decay is not going to happen, since so few microbes can live at that temperature. What would happen?
130 is within the temperature danger zone. You will have microbial growth. You need to get over 141 to stop it, and higher to kill them.
Outside of that, it’s going to turn into mush. What is being broken down is the connective tissue that give it form. If you just broke all of that down, you just have a blob of something.
It probably wouldn’t be safe to eat, and it certainly wouldn’t be appetizing.
Our sous vide has cooked beef (chuck) for nearly three days and it comes out tender as filet Mignon. The water gets a little discolored after that amount of time and it leaves a metallic smell in the container. I wonder if the bag would hold for a year at around 150F.
Even if you kept it at say… 145 (a perfectly good pasteurization temp), the enzymes in the meat would just keep on breaking it down until all of their substrates were gone. So you’d end up with something approaching a soup I imagine. I think it would be safe to eat, but deeply unappetizing.
But it would happen in a lot less than a year I’d think- probably on the order of days or weeks.
It’s a time and temperature equation, so you need to hold it at 130F for two hours or so to kill the microbes. That page suggests (with charts labeled FDA!) that 136F is the minimum safe temperature for poultry, but that “meat” can be cooked as low as 130F and still be safe, as long as it is held at that temperature long enough.
All bets are off if your meat is infected with extremophiles.
At Serious Eats they have a page showing the difference in cooking steak at 130F for 1 hour, 4 hours, and 24 hours. I expect after 24 hours the breakdown will just keep increasing, but I don’t know what the final result will be. I do brisket, in the form of corned beef, for 48-72 hours, and it is fine, but that is a different cut than steak.
Okay, that’s fascinating, and disgusting–thanks! He cooked it at 131 F, and that might not be hot enough to kill bacteria. If it is, I can’t account for the rot.
And thanks to others who explained how the meat would mush. That’s a pretty good answer to my question.
Rancidity of fat is caused by hydrolysis of fats and oxidation of fatty acids. It can be mediated by bacteria, but most often it’s just when unrefrigerated fats are exposed to oxygen for a long time. Heating accelerates it.
When first I read Sous vide for a year, I thought the thread would be asking about the feasibility of sous vide cooking every day for one year. I was eager to consider this “challenge”, as I enjoy sous vide cooking.
Specifically, that’s the USDA FSIS 7-log10 lethality at 130 °F. Possibly just for salmonella though; I’d have to check. And some bugs survive better at hotter temperatures than others. Not necessarily ones that will hurt you, but they may smell like dead feet.
I’m assuming you’re using Ziploc bags, which aren’t really ideal for longer sous vide baths. If it’s not that, you should investigate the problem as I’d be wary of eating anything that was sitting in discolored, metallic-smelling water for days. I’ve done the Modernist Cuisine 72 hour short ribs with a vacuum sealer and there is no change to water color nor is there any smell, as nothing is escaping from the bag. If you are vacuum sealing it and it’s leaking, try double bagging.
