Put the corned beef into the crockpot and season it with the spice packet. The fat side should be upward.
Add garlic and beer around it and sprinkle sugar.
Cover and cook on low for 3-4 hours.
After that, remove the lid and add potatoes, carrots. Cover again and cook for 2.5-3 hours or until potatoes and beef is tender.
Remove the corned beef from the crockpot and transfer it to the cutting board. Let it sit for 15-20 minutes before slicing.
Slice and serve with potatoes and carrots and garnish with parsley.