Pastrami is smoked beef from a cow. This age-old practice was traditionally used to preserve meat before refrigeration was widely available. Made from the brined beef brisket of the cow, which is better known as corned beef, pastrami undergoes a smoking process that makes it more stable for storage.
Smoking the meat also gives pastrami the distinct flavor that is not present in corned beef. Corned beef is traditionally soaked in strong salt and sugar brine during the winter months to take advantage of the naturally cooler temperatures and help to preserve the meat. This process, called brining, prevents bacterial spoilage due to the high salt content.