Knowing how to cook corned beef is almost a mandatory skill if you have even a drop of Irish blood in your veins. Corned beef is a quintessential American Irish tradition, although many Americans only eat it once a year, on St. Patrick's Day. Corned beef was one of Ireland's main exports until 1825; County Cork was the largest producer for many decades. The British Army often survived on cans of it during their many and bitter campaigns across Europe. Today, however, corned beef is far more popular in America than it is in Ireland.