All a sous vide machine does is adjust the temperature of the water as needed, which you can do yourself. You can DIY this technique with a pot, zip-close kitchen bags, some binder clips (seriously!) and an accurate thermometer.
Step 3: Prep Your Meat
I marinated my steaks first , then used water displacement to seal each steak in an individual bag.
To do this:
1.fill your sink with water
2.place the meat in a bag without sealing the top, slowly sink the bag under the water (being careful not to let water seep in the open top) until only the zipper part of bag is above the water.
This produces something similar to a vacuum seal, if you have a vacuum sealer feel free to use it instead.
Step 2: Set Up Your “cooker”
I wrapped the floral wire around the thermometer and hooked it over the side of the cooler to suspend the thermometer near the top of the cooler.
Pour HOT water into the cooler about half way , then add cool water until you reach the desired temp (135 degrees is a perfect medium rare steak in my mind. This temp works well on most cuts of beef but if you are preparing a traditionally tough steak cut, you will want to use a higher temp)
( I found a comprehensive guide on sous vide temperatures and cook times for most cuts of meat here )
How to cook steak sous vide without a machine
FAQ
Can you sous vide meat without a machine?
How do you improvise sous vide?
How do you cook sous vide eggs without a machine?