Prepare your chicken or turkey for roasting. Many people like to use a rub or seasoning to add extra flavor to the meat.
Set the appropriate can holder on a flat surface. Most keg roasters come with a set of two-can or three-can holders and a taller, single-can holder for turkeys. Open the can or cans of beer. Drain or drink approximately 1/3 from each can. Insert the can or cans into the beer holders. Use one can of beer for each bird you plan to cook.
Slide the prepared bird or birds onto the can holders. Set the bird and the cans on the diffuser plate inside of the keg roaster. Put the lid on the keg roaster.
Light the keg roaster. This might vary depending on your model. However, for most models, open the valve on your propane tank and push the starter button. Adjust the heat with the dial until it reaches 325 degrees Fahrenheit. Maintain this temperature throughout the roasting process.
Allow the bird to cook for around 90 minutes. Carefully remove the lid. Use oven mitts to protect your hands from the heat.
Insert the meat thermometer into each thigh. Turkeys are considered thoroughly cooked when the internal temperature reaches 160 degrees. Chickens are considered done when they reach an internal temperature of 180 degrees.
Remove the bird or birds from the roaster. Allow them to cool for at least 10 minutes. Remove them from the beer can holders. Discard the beer cans. Slice and serve the chicken or turkey.