Depending on the size of the beef brisket being cooked and the cooking method, pastrami takes about 3 to 4 hours to cook. An already cooked pastrami also takes about 3 hours to reheat. However, if one includes the time the pastrami spends brining, the actual preparation time takes anywhere from 1 to 3 weeks.
Pastrami is made from beef brisket, one of the cheaper cuts of beef. The first step in turning a brisket into a whole pastrami is to season and brine the meat. Brine is essentially extremely salty water that often has some spices added to it. Spices added to pastrami brine typically include pepper, bay leaves, cloves, garlic and thyme. In addition, brown sugar is usually added to the brine. The brisket is then placed into the brine to soak, completely covered at all times, for 1 to 3 weeks. The process of brining results in an extremely tender and juicy cut of meat. After the brining, the pastrami is dried off and encased in a crust of pepper and sometimes other spices such as coriander. The pastrami is then smoked in a smoker for 3 to 4 hours. After it cools off a little, it can either be sliced finely or sold as a whole pastrami.
A whole pastrami should be reheated very slowly, boiling over a low heat for about 3 hours. Once the reheated pastrami is tender, it can be dried off and sliced.