Pot roast cooked in a slow cooker or Crock-Pot should have at least 1 cup of water, but cooks may add several cups if they prefer extra gravy. Bottled steak sauce, condensed soup, wine or broth are an acceptable substitute for some or all of the water.
Kraft's slow-cooker pot roast recipe calls for just ½ cup of water mixed with ½ cup of prepared steak sauce, for a total of 1 cup of liquid. Campbell's, on the other hand, recommends using a 10-ounce can of condensed soup instead of water or other liquids. The Food Network's recipe uses 3 cups of beef broth and 1 cup of wine instead of water, and it suggests mixing the wine with flour before adding it to the crock pot. The flour thickens the liquid as the roast cooks.