How Long To Cook London Broil In Crock Pot | Tender Timing

A 2- to 3-pound London broil needs 6–8 hours on low or 3–4 hours on high until sliceable and at least 145°F.

London broil turns out best in a crock pot when you treat time as a range, not a clock you can ignore. The cut is lean, so low heat, enough liquid, and a clean slice across the grain matter as much as the hour count.

For most home kitchens, low is the better setting. It gives the fibers time to relax before the outside dries out. High works when dinner is closer, but it leaves less room for error, mainly with thinner pieces.

Cooking London Broil In A Crock Pot For Tender Slices

Start with a thawed 2- to 3-pound London broil, about 1½ to 2 inches thick. Pat it dry, season it well, then sear it for a deeper beef flavor if you have five spare minutes. Searing is not required for safety, but it helps the sauce taste less flat.

Add sliced onion or carrots to the bottom of the crock. Set the beef on top, then pour in ¾ to 1 cup of broth, stock, or a tomato-based sauce. The meat does not need to swim. Too much liquid can leave the sauce thin and the beef bland.

The safest habit is to thaw the meat before slow cooking. Frozen meat can stay cold in the center too long, and that can throw off the timing before the outer edges are done.

Best Time By Setting

Use these ranges for a thawed London broil in a 5- to 6-quart crock pot:

• Low: 6 to 8 hours for sliceable beef.
• High: 3 to 4 hours for sliceable beef.
• Low for softer beef: 8 to 9 hours if the cut is thick or has more connective tissue.

Check early the first time you make it in your slow cooker. Some crocks run hot, and a lean cut can go from tender to dry before the timer ends. When the meat reaches a safe temperature and a fork meets gentle resistance, pull it out and let it rest.

What Temperature Should London Broil Reach?

Food safety starts at 145°F with a 3-minute rest for beef steaks and roasts. A slow-cooked London broil may climb well past that, especially near the end of a long cook. That is normal, but higher heat does not always mean better texture.

For slicing, many cooks prefer pulling the meat once it is safely cooked and still firm enough to hold neat slices. For softer pot-roast texture, cook longer on low, then slice thickly or pull apart in bigger pieces.

London Broil Crock Pot Timing Chart

The table below gives practical ranges for common sizes. Thickness and crock strength change the result, so use the low end as your first check point.

One more timing detail: keep the lid on. Each peek releases heat and can add 15 to 20 minutes to the cook. If you need to check doneness, do it near the end with a probe thermometer, then close the lid again while you finish the sauce. Older slow cookers and newer digital models can run differently, so the first batch is your calibration run.

Write down the cut weight, setting, and finish time on a recipe card. Next time, you’ll know your crock instead of guessing. USDA slow cooker food safety advice says meat should be thawed before slow cooking, so plan the fridge thaw before you set the timer.

Meat Size And Setup	Cook Time	Best Use
1½ lb, thin cut, low setting	5–6 hours	Thin slices for sandwiches
1½ lb, thin cut, high setting	2½–3 hours	Same-day dinner
2 lb, 1½-inch cut, low setting	6–7 hours	Classic sliced beef
2 lb, 1½-inch cut, high setting	3–3½ hours	Faster sliced beef
3 lb, 2-inch cut, low setting	7–8 hours	Family platter slices
3 lb, 2-inch cut, high setting	3½–4½ hours	Firmer slices
3 lb with potatoes and carrots	8–9 hours on low	One-pot meal
Thick cut for pull-apart beef	8–10 hours on low	Shredded bowls or tacos

How To Keep London Broil From Turning Dry

Use the USDA safe minimum internal temperature chart as the safety floor: beef steaks and roasts need at least 145°F and a 3-minute rest. Tenderness may need more time, but dryness usually comes from pushing lean beef too far.

London broil is often top round or flank, both lean cuts. That means it lacks the fat that saves chuck roast during long cooking. A few small choices make a big difference.

Use Enough Liquid, Not Too Much

A small pool of liquid keeps steam moving and helps create sauce. Broth, crushed tomatoes, onion soup, salsa, or a thin gravy all work. Aim for ¾ to 1 cup for a 2- to 3-pound piece, then add more near the end only if the crock looks dry.

Acid can help flavor the meat, but do not overdo it. A splash of Worcestershire sauce, balsamic vinegar, or tomato paste is enough. Too much vinegar can give the outside a tight, stringy bite.

Slice Against The Grain

Before cooking, note the direction of the long muscle fibers. After resting, cut across those lines with a sharp knife. Thin slices feel more tender because the fibers are shorter when you chew.

Resting matters too. Move the beef to a cutting board, tent it loosely, and wait 10 minutes. The juices settle, and the slices stay cleaner. FoodSafety.gov’s safe minimum temperature chart matches the 145°F beef mark and the 3-minute rest rule, so a 10-minute rest fits well for both safety and texture.

Seasoning And Liquid Pairings That Work

London broil takes bold seasoning well because the meat is lean and mild. Salt early if you can. A salted rub placed on the beef 30 minutes before cooking helps flavor the surface and draws out less moisture than a last-second heavy sprinkle.

For a classic dinner, use beef broth, onion, garlic, thyme, and black pepper. For sandwiches, use broth, pepperoncini brine, oregano, and a small pat of butter. For tacos, use salsa, cumin, smoked paprika, and onion.

Timing Changes For Vegetables And Sauce

Vegetables can change the clock because they fill the crock and slow heat movement. Dense potatoes and carrots should sit on the bottom or along the sides, where heat is strongest. Cut them into 1- to 1½-inch pieces so they finish near the same time as the beef.

If you want a thicker sauce, lift out the beef and vegetables after cooking. Whisk 1 tablespoon cornstarch with 1 tablespoon cold water, stir it into the hot liquid, then cook on high for 10 to 15 minutes.

Problem	Likely Cause	Fix Next Time
Dry slices	Cooked too long on high	Use low and check 1 hour early
Tough center	Cut was thick or cold	Thaw fully and add time on low
Bland beef	Too little salt or weak liquid	Salt early and use broth
Watery sauce	Too much added liquid	Start with ¾ cup and thicken later
Stringy texture	Sliced with the grain	Turn the meat and cut across fibers

A Reliable Crock Pot Method

Season a 2- to 3-pound London broil with 1½ teaspoons kosher salt, 1 teaspoon black pepper, 1 teaspoon garlic powder, and 1 teaspoon smoked paprika. Add sliced onion to the crock. Place the beef on top, then pour in 1 cup beef broth mixed with 1 tablespoon Worcestershire sauce and 1 tablespoon tomato paste.

Cook on low for 6 to 8 hours. Start checking at 6 hours for a thinner piece and 7 hours for a thicker one. The beef should reach at least 145°F and feel tender when pierced, but it should not collapse unless you want shredded meat.

Rest the beef for 10 minutes. Slice it thinly across the grain, then spoon warm sauce over the top. If the sauce tastes weak, simmer it without a lid in a small pan for a few minutes. That step tightens the flavor without drying the meat.

Final Timing Takeaway

For the most reliable result, cook London broil in a crock pot for 6 to 8 hours on low. Use high only when you can check it closely after 3 hours. The timer gets you close, but the thermometer and the slice test tell you when dinner is ready.