Corned Beef with spice

1 (3 pound) corned beef brisket with spice packet 1 cup brown sugar 4 (12 fluid ounce) cans or bottles Irish stout beer (such as Guinness®), or more if[...]

1 (5 1/2 pound) corned beef brisket with spice packet 7 small potatoes, peeled and diced 4 carrots, peeled and diced 3 cloves garlic, chopped 1 medium onion,[...]