Celebrating holidays or enjoying the outdoors with family members while picnicking, grilling or barbecuing has generated the expression "picnic roast." Pork roast, shoulder blade roast and Boston butt are all roasts that conjure up the wonderful aroma of a home-cooked meal, replete with mashed potatoes and gravy, carrots or green beans. But a conventional picnic roast does not come from beef.

Traditionally speaking, a picnic roast is defined as a pork shoulder roast, which is considered the fattest and toughest part of a pig. Southern cooks typically smoke or barbecue the roast for long periods of time and refer to it as pulled pork or a picnic roast.

According to the USDA, pork is divided into four basic cuts. Shoulder, loin, side and leg. Pork shoulder picnic or shoulder arm picnic are labels defined by the government and come from the shoulder cut. Over time, the term "picnic roast" has come to mean a barbecued pork roast.

Pork is meat from a domesticated pig, and is considered an important American food staple. In the 1800s, people who lived away from the farms and weren’t able to eat fresh meat ate salt pork, which was heavily salted to preserve the meat. Today, much of the pig is cured for ham, bacon or sausage.

As opposed to the southern tradition of barbecuing a pork roast, non-traditional cooks may substitute a beef roast and serve it at a picnic, also calling it a picnic roast. Texans are known for their barbecued beef brisket, another slow-cooked roast served at picnics. However, they typically call the picnic a barbecue.

Whatever the cut of pork roast, the meat can be seasoned by using a needle to inject flavoring solution into the meat. A blend of apple juice, cider vinegar and Worcestershire sauce makes a tasty solution. Then use a seasoning rub, and slow-cook the roast in the oven or smoker. Serve with barbecue sauce on the side.