Vast difference in cooking times prescribed

I am a sous vide newbie confused about cooking times for beef.
I get that different cuts or thickness of beef require different cooking times. But the estimates seem to range from 1-4 hours to 36 hours! What is going on there?
Also, I cooked a piece of beef that had quite a bit of fat in it, and it turned out horrible. Should I just stick to more lean beef in the future for use in the sous vide?

@samlinton You’re right, there are factors like thickness and cuts of meat that determine the cook time ranges. For example, ribeye may be cooked from anywhere between 1-4 hours.

A general rule of thumb is that longer cooker time will get you more tender results. Serious Eats has a really great guide on sous vide steaks. Talks about everything you’re asking here. There’s also a basic time + temp explanation in the community.

You can cook fatty steaks - ribeye is one of them. What was the outcome of the fatty piece of beef you cooked up? What kind cut of beef?

Thanks, that looks like a great resource.
The meat that I tried was chuck roast, but I think it had an unusual amount of fat throughout it. The fat became a bit rubbery.

But I have some ribeyes I am going to try next!

How long did you cook the chuck for? With something like chuck, the time needs to be long enough for the connective tissue to breakdown and provide some tenderness to what is a harder working muscle.

When cooking with sous vide one can think of the temperature as setting the ‘doneness’ of the meat and time controlling the texture. This is, of course, a simplification of the process, but it does help a little with planning.

With cuts of beef usually used for steaks, the muscle in question does a low amount of work and is naturally tender. Therefore we can cook for shorter times, from an hour up to four, and still get a tender piece of meat.

Harder working muscles, those often used for slow roasts or casseroles and braises, require slower cooking to break down the collagens to produce tender end results. These tend to be cheaper cuts and frequently much more flavourful than the steaks. With sous vide they can be cooked for a long time but still be kept at the medium rare stage due to the temperature control. That’s where things get interesting. With the control sous vide offers you can have a super flavourful piece, like chuck or cheek or blade that can be served as a beautiful medium rare steak and cut with a bread and butter knife.