Corned beef can also be made from the beef round primal cut. Both the round and the brisket are relatively tough cuts of meat that are best cooked by slow, moist-heat cooking. A good corned beef is quite tender with a delicious salty flavor.
The brine for making corned beef is similar to the brine used for making pickles. Thus, it's fair to say that corned beef is essentially pickled beef.
One of the key ingredients in making corned beef is a curing salt called prague powder, which is what gives the corned beef its distinctive pink color. And yes, if you're wondering, prague powder is in fact made of sodium nitrite, which despite what you may have heard, is a harmless anti-oxidant that helps prevent the growth of bacteria that cause spoilage and food poisoning.
Sodium nitrite is two things: salt (sodium) and nitrogen (nitrite). Salt you know about. Nitrogen happens to be the single biggest component of our atmosphere. Every lungful of air you breathe consists of 78 percent nitrogen. Because there's so much nitrogen in our atmosphere, it's also in our soil, which means it's also in whatever grows in the soil -- namely vegetables.
Indeed, veggies like spinach, celery, and lettuce contain concentrations of sodium nitrite up to ten times higher than in cured meats.
As a matter of fact, celery contains so much nitrite that so-called "nitrate-free" products simply substitute celery juice for prague powder. Thus "nitrate-free" meats generally contain up to ten times more sodium nitrite than their conventional counterparts.
Brisket is a good cut of beef to use for making corned beef because it has a nice fat content. Beef round, on the other hand, it much leaner. So it just depends on your preference. The higher fat content of brisket will produce a moister corned beef (although much of the actual fat will melt away while it cooks).