First, you need to get rid of the excess water from your tofu. Do this by draining all of the water from the package the tofu came in.
Then, use a kitchen towel or paper towel to pat the tofu down. I liked to add some heavy objects on top and leave it for a few minutes, to help get rid of the extra moisture.
Once you have removed the excess water, throw the tofu in a blender. Then add the lemon juice, nutritional yeast, apple cider vinegar, garlic powder, and onion powder.
Blend everything really well for several minutes, until everything is smooth and creamy.
Now just refrigerate the sour cream and add it to whatever foods you like! I love adding it to a seven layer tip, baked potatoes, tacos, or anything else you can think of!