Cook brisket at 275°F for about 60 minutes per pound, so a 5-pound brisket takes roughly 5 hours. For sliced beef brisket, cook until it reaches 145°F, then rest 3 minutes; many cooks go longer for tenderness.
How Long To Cook Brisket In Oven At 275: plan on about 60 minutes per pound, so a 5 lb brisket takes roughly 5 hours before resting and slicing.
Use the time as a planning estimate, not the doneness test. For beef brisket, cook to at least 145°F (63°C) and rest 3 minutes; many cooks take brisket longer for tenderness, but USDA safe minimum doneness is 145°F with that rest.
The Short Answer, With Numbers
At 275°F, plan on about 60 to 75 minutes per pound for oven-braised brisket, plus resting time. A 5 lb brisket usually takes about 5 to 6 hours 15 minutes.
Use the clock for planning, but use doneness checks to finish. Brisket is safely cooked once it reaches the USDA figure for beef roasts, then rests as required.
| Relevant food | Safe minimum internal temperature | Rest time |
|---|---|---|
| Beef, pork, veal and lamb – steaks, chops, roasts | 145°F (63°C) | 3 minutes |
| Leftovers, reheated | 165°F (74°C) | None |
Oven Time At 275°F By Brisket Weight
Use these as planning ranges for a covered pan or tightly wrapped brisket in a 275°F oven. Very lean, thick, or unwrapped brisket can run longer.
| Brisket weight | Estimate at 60 min/lb | Estimate at 75 min/lb |
|---|---|---|
| 3 lb | 3 hours | 3 hours 45 minutes |
| 4 lb | 4 hours | 5 hours |
| 5 lb | 5 hours | 6 hours 15 minutes |
| 6 lb | 6 hours | 7 hours 30 minutes |
| 8 lb | 8 hours | 10 hours |
| 10 lb | 10 hours | 12 hours 30 minutes |
Worked example: a 4.5 lb brisket at 275°F needs about 4 hours 30 minutes to 5 hours 38 minutes. Start checking earlier if it is flat-cut, thin, or trimmed closely.
For a 6.25 lb brisket, multiply 6.25 by 60 to 75. That gives 375 to 469 minutes, or about 6 hours 15 minutes to 7 hours 49 minutes.
A small 2.5 lb flat may finish in about 2 hours 30 minutes to 3 hours 8 minutes. A thick point cut of the same weight can take longer because thickness matters more than scale weight.
If the brisket is uncovered the whole time, expect the outside to dry faster and the cook to be less predictable. Covered, tightly foiled, or lidded braising keeps the estimate closer to the table.
If you add cold liquid, cold vegetables, or a heavy cold pan, add about 15 to 30 minutes to the early part of the cook. The oven must heat the pan and contents before the meat cooks steadily.
Rest the cooked brisket before slicing. For the USDA beef-roast minimum, the required rest is 3 minutes, but brisket slices cleaner after a longer counter rest in its juices.
For reheating cooked brisket, use the separate USDA leftovers rule: reheat leftovers to 165°F. Do not use the lower beef-roast figure for reheated slices or chopped brisket.
Brisket Time At 275
At 275°F, plan on about 60 to 75 minutes per pound for a whole packer brisket, and about 45 to 60 minutes per pound for a smaller flat.
That means a 10 lb packer brisket usually takes 10 to 12.5 hours in the oven at 275°F before resting.
| Brisket size | Typical oven time at 275°F | Best use |
|---|---|---|
| 3 lb flat | 2.5 to 3.5 hours | Small dinner, lean slices |
| 5 lb flat | 4 to 5.5 hours | Family meal |
| 8 lb brisket | 7.5 to 10 hours | Medium brisket |
| 10 lb packer | 10 to 12.5 hours | Classic full brisket |
| 12 lb packer | 12 to 15 hours | Large gathering |
| 15 lb packer | 15 to 18.5 hours | Very large brisket |
Fast timing formula
Use this estimate: brisket pounds × 1.25 hours for a packer, or pounds × 1 hour for a flat. Then add a rest of at least 30 to 60 minutes.
Example: a 6 lb flat at 275°F takes about 6 hours. Start checking tenderness around 5 hours, because flats can finish faster than packers.
Example: a 12 lb packer takes about 15 hours using the 1.25-hour rule. If dinner is at 6 p.m., start around 2 to 3 a.m. or cook ahead.
Covered vs uncovered at 275°F
If you cook the brisket uncovered the whole time, expect the longer end of the range: 75 minutes per pound for a packer. The bark gets firmer, but the cook runs longer.
If you wrap tightly in foil after the outside is dark and set, use the shorter range: 60 minutes per pound for a packer. Foil speeds the cook and keeps the flat moister.
Butcher paper usually lands in the middle. It protects the meat less than foil, so a 10 lb brisket may take closer to 11 to 12 hours instead of 10.
Edge cases that change the time
A thin 3 to 4 lb flat can be done in under 4 hours. Check it early; small flats dry out faster than thick point-end pieces.
A thick 14 to 16 lb packer can push past 18 hours, especially if it goes in cold, has a thick fat cap, or is cooked uncovered.
Opening the oven often can add 20 to 40 minutes. Each long door opening drops oven heat and slows the cook, especially during the middle phase.
For food safety, beef roasts have a USDA safe minimum internal temperature of 145°F with a 3-minute rest. Brisket is usually cooked longer so the connective tissue softens.
For serving time, build in a buffer. A brisket can finish early and rest, but it cannot be rushed much without turning tough. Add 1 to 2 extra hours to your schedule.
Time By Brisket Weight
At 275°F, plan on about 45 to 60 minutes per pound for a whole packer brisket, plus a rest. A flat-only brisket often runs closer to 50 to 70 minutes per pound because it is leaner and can stall longer.
| Brisket weight | Estimated oven time at 275°F | Practical planning window |
|---|---|---|
| 3 lb flat | 2 hr 30 min to 3 hr 30 min | Start checking texture around 2 hr 15 min |
| 4 lb flat | 3 hr 20 min to 4 hr 40 min | Common weeknight size |
| 5 lb flat | 4 hr 10 min to 5 hr 50 min | Allow 6 hr before resting |
| 6 lb flat or small point | 5 hr to 7 hr | Wrap if it stalls hard |
| 8 lb brisket | 6 hr to 8 hr | Good overnight or early-morning cook |
| 10 lb packer | 7 hr 30 min to 10 hr | Plan a 10 hr oven window |
| 12 lb packer | 9 hr to 12 hr | Start early; rest can cover timing |
| 14 lb packer | 10 hr 30 min to 14 hr | Large, thick packers vary most |
Worked Examples
For a 4 lb brisket flat, multiply 4 by 50 to 70 minutes. That gives 200 to 280 minutes, or about 3 hr 20 min to 4 hr 40 min in a 275°F oven.
For a 10 lb whole packer, multiply 10 by 45 to 60 minutes. That gives 450 to 600 minutes, or about 7 hr 30 min to 10 hr, before resting.
For a 12 lb packer served at 6:00 p.m., aim to have it done by 4:00 p.m. If you expect 9 to 12 hours in the oven, start between 4:00 a.m. and 7:00 a.m.
Why The Range Is Wide
Two briskets of the same weight can finish hours apart. Thickness matters more than weight. A compact 8 lb brisket can take longer than a long, thin 10 lb brisket.
A brisket flat is usually lean and rectangular. It may need more time per pound than a fatty point because it dries faster and benefits from a slower finish after wrapping.
A whole packer has both flat and point. It often cooks more evenly because the point has more fat, but the thickest section controls the finish time.
Edge Cases At 275°F
If the brisket is under 3 lb, do not rely on a full per-pound formula. Start checking after 2 hours; small flats can dry out quickly.
If the brisket is over 14 lb, use the same 45 to 60 minutes per pound, but build in a larger buffer. A 16 lb packer may need 12 to 16 hours.
If you wrap in foil or butcher paper after the bark is set, the total time often drops by 30 to 90 minutes. Foil speeds the cook more than paper.
If the brisket was trimmed very aggressively, check early. Less fat and less thickness can shorten the cook by about 30 to 60 minutes.
For food safety, beef roasts have a USDA safe minimum internal temperature of 145°F followed by a 3-minute rest. Brisket is usually cooked longer for tenderness, not for a higher safety requirement.
Flat Versus Point Timing
At 275°F, a brisket flat usually cooks faster per pound than a point, but it dries out sooner. Plan the flat at about 55 to 70 minutes per pound, and the point at about 70 to 90 minutes per pound.
The flat is thin, lean, and even. A 4 lb flat often takes 4 to 4 hours 40 minutes. A 6 lb flat often takes 5 hours 30 minutes to 7 hours. An 8 lb flat often takes 7 hours 20 minutes to 9 hours 20 minutes.
The point is thicker, fattier, and less uniform. A 4 lb point often takes 4 hours 40 minutes to 6 hours. A 6 lb point often takes 7 to 9 hours. An 8 lb point often takes 9 hours 20 minutes to 12 hours.
Quick Timing Chart at 275°F
| Cut | Weight | Typical Oven Time at 275°F |
|---|---|---|
| Flat | 4 lb | 4 hr to 4 hr 40 min |
| Flat | 6 lb | 5 hr 30 min to 7 hr |
| Flat | 8 lb | 7 hr 20 min to 9 hr 20 min |
| Point | 4 lb | 4 hr 40 min to 6 hr |
| Point | 6 lb | 7 hr to 9 hr |
| Point | 8 lb | 9 hr 20 min to 12 hr |
For a whole packer brisket, do not average the flat and point weights. Time it by total weight, but expect the point end to lag. A 12 lb packer at 275°F commonly needs 10 to 14 hours.
A trimmed 10 lb packer may finish closer to 9 to 11 hours. A heavy, untrimmed 14 lb packer may need 13 to 16 hours, especially if the fat cap is thick or the point is tall.
Worked Examples
Example 1: a 5 lb flat at 275°F. Use 55 to 70 minutes per pound. That gives 275 to 350 minutes, or about 4 hours 35 minutes to 5 hours 50 minutes.
Example 2: a 7 lb point at 275°F. Use 70 to 90 minutes per pound. That gives 490 to 630 minutes, or about 8 hours 10 minutes to 10 hours 30 minutes.
Example 3: a 12 lb whole brisket. Start checking texture around hour 9, but budget 10 to 14 hours. If serving at 6 p.m., start no later than 4 a.m. to allow a holding buffer.
Shape matters more than label. A flat that is 2 inches thick may cook much faster than a compact 4-inch point of the same weight. Thickness adds time because heat must reach the center more slowly.
Wrapping changes the clock. If you wrap tightly in foil or butcher paper after several hours, the cook may shorten by 1 to 2 hours on a medium brisket. An unwrapped brisket can run longer but develops a drier bark.
USDA lists beef roasts as safe at 145°F with a 3-minute rest. Brisket is usually cooked longer for tenderness, so timing should be treated as a planning range, not the final test.
For slices, flats are easier to manage if you stop before the lean end crumbles. For chopped brisket, the point is forgiving and can take extra oven time because its fat and connective tissue protect it.
If the flat and point finish unevenly, separate them. Return the firmer piece to the oven and tent the finished piece. This prevents an overcooked flat while the thicker point continues to soften.
How To Oven Cook Brisket
At 275°F, plan on about 45 to 60 minutes per pound for a whole brisket or flat, plus a 30 to 60 minute rest. A 5 lb brisket usually takes 4 to 5 hours; an 8 lb brisket usually takes 6 to 8 hours.
Oven Brisket Timing At 275°F
| Brisket weight | Estimated cook time | With rest time |
|---|---|---|
| 3 lb | 2 hr 15 min to 3 hr | 2 hr 45 min to 4 hr |
| 5 lb | 3 hr 45 min to 5 hr | 4 hr 15 min to 6 hr |
| 8 lb | 6 hr to 8 hr | 6 hr 30 min to 9 hr |
| 10 lb | 7 hr 30 min to 10 hr | 8 hr to 11 hr |
- 1. Trim the brisket. Leave about 1/4 inch of fat on top. Remove thick hard fat pockets, because they will not fully render in the oven. Pat the meat dry so seasoning sticks evenly.
- 2. Season by weight. Use 1 teaspoon kosher salt per pound of brisket. For a 5 lb brisket, use 5 teaspoons salt. Add black pepper, garlic powder, onion powder, and paprika if desired.
- 3. Set up the pan. Place the brisket fat-side up in a roasting pan or baking dish. Add 1 cup beef broth, water, or stock for a 3 to 5 lb brisket. Use 1 1/2 to 2 cups for 6 to 10 lb.
- 4. Cover tightly. Seal the pan with foil, crimping the edges well. Tight covering matters at 275°F because brisket needs moist heat to soften without drying out during the long cook.
- 5. Bake at 275°F. Cook 45 to 60 minutes per pound. Example: a 6 lb brisket needs about 4 1/2 to 6 hours. Start checking at the low end, but do not expect it to be done by the clock alone.
- 6. Check doneness correctly. For food safety, beef roasts must reach 145°F and rest 3 minutes. For brisket texture, it should feel very tender when pierced, especially in the thickest part.
- 7. Rest, slice, and serve. Rest covered for 30 to 60 minutes. Slice across the grain into 1/4 inch slices. If the slices shred, cut thicker. If they feel tough, return the covered brisket to the oven.
Worked Examples
For a 4 lb brisket at 275°F: 4 × 45 minutes = 3 hours on the early side. 4 × 60 minutes = 4 hours on the long side. Add 30 to 60 minutes of resting time.
For a 7 lb brisket at 275°F: 7 × 45 minutes = 5 hours 15 minutes. 7 × 60 minutes = 7 hours. With rest, plan for about 5 hours 45 minutes to 8 hours total.
If your brisket is a thin flat, start checking closer to 45 minutes per pound. If it is a thick point or a whole packer, expect closer to 60 minutes per pound.
If the pan goes dry, add 1/2 cup hot broth or water and reseal. If the top is pale, uncover for the final 20 to 30 minutes to darken the surface.
When To Start Checking
At 275°F, start checking brisket well before the “hours per pound” estimate says it is done. Use time only as a trigger to begin checking; use tenderness and temperature to decide when to pull it.
For a whole packer brisket, start checking at about 45 minutes per pound. For a flat, start at about 40 minutes per pound. For a small trimmed piece, start even earlier: 35 minutes per pound.
| Brisket | Oven at 275°F | Start Checking |
|---|---|---|
| 3 lb flat | About 3 to 4 hours | At 1 hour 45 minutes |
| 5 lb flat | About 4 to 5 1/2 hours | At 3 hours 20 minutes |
| 8 lb point or small packer | About 6 to 8 hours | At 6 hours |
| 12 lb whole packer | About 9 to 12 hours | At 9 hours |
| 15 lb whole packer | About 11 to 14 hours | At 11 hours 15 minutes |
What You Are Checking For
Check the thickest part of the flat first. That is usually the last part to soften. A probe, skewer, or thermometer stem should slide in with little resistance, like going into softened butter.
Brisket is typically sliced when it is tender in the high doneness range, often around 195°F to 205°F. That is a texture target, not the USDA safety minimum.
For food safety, beef roasts have a USDA safe minimum internal temperature of 145°F with a 3-minute rest. Brisket usually cooks far beyond that because collagen needs more time to soften.
Worked Examples
Example 1: A 5 lb brisket flat at 275°F. Start checking at 3 hours 20 minutes. If it reads 185°F and feels tight, keep cooking and check again in 30 minutes.
Example 2: A 12 lb packer. Start checking at 9 hours. If the point feels soft but the flat is firm, judge by the flat. Check every 30 to 45 minutes.
Example 3: A 3 lb trimmed flat. Start checking at 1 hour 45 minutes. Small flats can dry out fast, so once it passes 180°F, check tenderness every 20 minutes.
Edge Cases That Change the Check Time
- Very thick flat: Start at the normal time, but expect a longer finish. Thickness matters more than weight once the brisket is over 2 inches thick.
- Heavy fat cap: Start checking on schedule, but the cook may run longer. Fat slows heat transfer and can make the surface look done before the flat is tender.
- Tightly wrapped brisket: It may finish faster after wrapping. Once wrapped, begin checking every 30 minutes.
- Unwrapped brisket: Expect a slower finish and more bark. Start checking on schedule, then continue at 45-minute intervals if it is still firm.
- Oven runs hot: If your oven swings above 300°F, start checking 30 to 45 minutes earlier than the table.
If the thermometer slides in easily in the point but not the flat, keep cooking. Pulling based on the point alone can leave the slices chewy.
If the flat is tender but the point is softer and fattier, pull the brisket. The point can handle extra softness; the flat is the part most likely to dry out.
Frequently Asked Questions
How long does brisket take in the oven at 275°F?
Plan on about 60 to 75 minutes per pound at 275°F. A 5 lb brisket usually takes 5 to 6 hours, while a 10 lb brisket often takes 10 to 12 hours. Time varies by thickness, fat, pan setup, and whether it is wrapped.
How long to cook a 3 lb brisket at 275°F?
A 3 lb brisket at 275°F usually takes about 3 to 4 hours. Start checking tenderness around the 3-hour mark. For food safety, beef roasts should reach at least 145°F and rest for 3 minutes, but brisket is typically cooked longer for tenderness.
How long to cook a 5 lb brisket in the oven at 275°F?
A 5 lb brisket usually needs about 5 to 6 hours at 275°F. If you wrap it tightly after the surface darkens, it may finish closer to 5 hours. Unwrapped brisket can take longer and may dry out more easily.
Should I cover brisket in the oven at 275°F?
Yes, for a moist oven brisket, cover or tightly wrap it once it has cooked for about 2 to 3 hours. Foil helps push through the stall and reduces drying. Keep some broth, juices, or rendered fat in the pan.
When should I start checking brisket at 275°F?
Start checking a small brisket after about 3 hours and a larger one after about 6 hours. Use time as an estimate, not the final test. The brisket is ready for serving when it is tender enough to slice cleanly across the grain.
