Slow Cooker Reuben-Style Corned Beef

June 13, 2025

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This slow cooker Reuben-style corned beef gives you deli-style sandwiches at home with very little work. A corned beef brisket cooks all day in beer with onion and garlic until it is tender enough to slice thin. Then you pile it on rye with Swiss cheese and sauerkraut and toast it until the cheese melts.

It takes about 15 minutes to get it into the pot. The slow cooker runs for 8 hours, so you can start it in the morning and make sandwiches for dinner. It is a fun meal for St. Patrick’s Day, game day, or any night you want something hearty.

Why This Slow Cooker Corned Beef Works

Low and slow makes it tender. Brisket is a tough cut. Eight hours on low breaks it down so it slices easily and stays juicy.
Beer adds flavor. A light beer gives the meat a mild, malty taste and keeps it moist the whole time.
The seasoning is already done. The spice packet that comes with the brisket handles most of the flavor.
Classic Reuben toppings. Swiss cheese, sauerkraut, and Thousand Island dressing turn the beef into a real deli sandwich.

Ingredients and Easy Swaps

3 pound corned beef brisket with seasoning packet: The flat cut is leaner and slices neatly. The point cut has more fat and is even more tender.
1 can (12 ounces) light beer: Swap in beef broth or water if you prefer not to cook with beer. The flavor will be a little milder.
1 onion and 3 cloves garlic: They sit under the beef and season the cooking liquid.
1 cup sauerkraut: Drain it well and squeeze out extra liquid so your bread stays crisp. Coleslaw works if you do not like sauerkraut.
6 slices Swiss cheese: Provolone or Muenster melt well too.
Rye bread and ½ cup Thousand Island dressing: Marbled rye or pumpernickel are good swaps. Russian dressing is the other classic Reuben sauce.

How to Make It at a Glance

Put the onion and garlic in the bottom of the slow cooker.
Set the corned beef on top, sprinkle on the seasoning packet, and pour in the beer.
Cover and cook on low for 8 hours, until the beef is fork tender.
Move the beef to a cutting board, rest it for 10 minutes, and slice it thin against the grain.
Layer the beef on rye bread with Swiss cheese and sauerkraut, then toast until the cheese melts.
Serve with Thousand Island dressing on the side or spread inside.

Common Mistakes to Avoid

Slicing with the grain. Look for the lines running through the meat and cut across them. Otherwise the slices turn stringy and chewy.
Skipping the rest. Cutting right away lets the juices run out. Ten minutes on the board makes a big difference.
Wet sauerkraut. Extra liquid soaks the bread. Squeeze it dry in a paper towel first.
Cooking on high. High heat can leave brisket tough. This cut needs the full time on low.

Variations

Rachel sandwich: Use coleslaw instead of sauerkraut for a milder, creamy version.
Reuben sliders: Build the sandwiches on slider buns in a baking dish, top with cheese, and bake at 350°F for 10 to 15 minutes.
Corned beef dinner: Add baby potatoes and carrots to the pot for the last 3 to 4 hours, and serve the beef sliced on a plate.
Reuben bowl: Skip the bread and serve the beef over sauerkraut with melted Swiss and a drizzle of dressing for a low-carb meal.

What to Serve With It

Reuben sandwiches go great with dill pickles and potato chips, just like a deli. For a warmer side, try oven fries, potato salad, or a bowl of tomato soup. A crisp green salad or vinegar coleslaw helps cut through the rich meat and cheese.

Make Ahead, Storage, and Reheating

Make ahead: Cook the corned beef a day early and chill it whole. Cold corned beef is actually easier to slice thin. Warm the slices in a little cooking liquid before building sandwiches.

Storage: Keep sliced corned beef in an airtight container with a spoonful of the cooking liquid for 3 to 4 days in the fridge. It freezes well for up to 3 months.

Reheating: Warm slices in a covered skillet with a splash of liquid over medium-low heat. Build fresh sandwiches rather than reheating assembled ones, since the bread gets soggy.

FAQ

Should I rinse the corned beef first?
A quick rinse removes some of the surface brine and makes it a little less salty. It is optional.

How do I know when it is done?
It should slide apart easily when you poke it with a fork. Corned beef is safe at 145°F, but it gets truly tender closer to 190°F to 200°F.

Can I make it without beer?
Yes. Use 12 ounces of beef broth or water instead.

What should I do with the leftovers?
Chop leftover corned beef and fry it with diced potatoes for corned beef hash. Top it with a fried egg for breakfast.

Can I cook the sandwiches in a skillet?
Yes. Butter the outside of the bread and cook in a skillet over medium heat for 3 to 4 minutes per side. Press down lightly with a spatula so the cheese melts and the bread turns golden.

One brisket makes enough for a round of sandwiches plus leftovers for hash or lunch the next day. The full recipe card with amounts and steps is right below.