In a medium pot set over high heat, combine 2 cups of the water, salt, sugar, garlic, 3 tablespoons pickling spices and pink curing salt. Stir mixture as it heats until sugar and salt are dissolved, about 1 minute. Transfer liquid to a container large enough for the brine and the brisket, then refrigerate until liquid is cool. Add remaining water.
Place brisket in the cooled liquid so it is completely submerged. Cover container and place in the refrigerator for 5 days, turning the meat once a day.
DAY SEVEN: COOK BEEF
Remove brisket from brine and rinse under cool water. Place in a pot just large enough to hold it, add ginger beer, then just enough water to barely cover. Add remaining 2 tablespoons pickling spices. Bring to a boil over high heat, then turn heat to low so liquid is barely simmering. Cover and let cook until you can easily insert a fork into the meat, about 3 hours, adding more water along the way if needed.
Transfer meat to clean storage container and strain braising liquid over the top. Refrigerate.
DAY EIGHT: FINISH AND ASSEMBLE
Add chilled meat and braising liquid to a large pot. Add brisket, potatoes and carrots and simmer till tender. Add cabbage and simmer for an additional 15 minutes.
To serve: Arrange vegetables on platter. Slice brisket thinly and arrange on top. Ladle braising liquid over and garnish with finely minced scallions.
Notes
"Pickling Spices" are a blend of Cinnamon, Allspice, Mustard Seed, Coriander, Bay Leaves, Ginger, Clove, Red Pepper, Black Pepper, Cardamom, Mace
Corned beef got its name from the dry curing process used to preserve the meat. A slice of beef was covered in “corns” (the English term for large, coarse pellets of salt), which would draw out the moisture and prevent the growth of bacteria.
Back in the 17th century, Ireland’s salt tax was significantly lower than that of England and France, which meant the country could import the highest quality salt at an affordable price. Around that same time, a new law was passed that prohibited the Irish (who considered cows to be sacred and rarely ate beef) from exporting live cattle to England (a beef-eating culture). So, with lots of salt and tons of cows, it’s no surprise that Ireland quickly became known for its corned beef production, exporting the meat across Europe and the Americas.
When the Irish population immigrated to America poor and escaping the Potatoe Famine back home, they began to purchase beef from kosher butchers, and in a weird twist of fate, the beef they could afford just happened to be corned beef, the thing their great grandparents were famous for.