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How Long To Smoke a 15 Pound Brisket

You’ve got a meat-loving group to entertain soon and you’re running out of ideas of what to prepare, but you know they all love a good, juicy smoked brisket. The only problem is … you’ve never prepared one. What do you do?

This article will not only answer how long it takes to smoke a 15-pound brisket, which is just the right size for your hungry guests, but it will also take you through the entire process of smoking your brisket to make the best beef brisket ever.

A board of sliced brisket with accompaniments
Smoked brisket is a southern party favorite, but how long should it be smoked for the best flavor?

So, read on to learn how to prepare your main dish and to determine how long to smoke a 15-pound brisket. (Pssst! It’s a formula based on a few factors…)

Preparing Smoked Brisket

You’ve got quite a few guests to entertain, so you don’t want to run out of brisket. A 15-pound brisket will feed over 20 people (23-27 depending on how much your guests eat).

That may even be enough for them to come back for more — because they’ll want to.

Smoking your 15-pound beef brisket will require attention to detail as you’ll find the little nuances about the meat makes a big difference in the outcome. Brisket science is all about breaking down connective tissue so that what remains after the cooking process is tender and juicy meat.

This guide will help you learn how to do just that.

Select Your Brisket

First things first – when buying a brisket, you want to buy it by the sealed pack. This means a whole packer brisket that is sealed in cryovac. So, purchasing the “full packer brisket” or “whole packer brisket” will be what you’re looking for at the market. This is just a whole brisket packed and sealed in plastic.

whole packer briskets in cryovac at the butcher
Whole briskets in cryovac

You can also have a butcher help your select your brisket.

You’ll find that the brisket has a lean side called the brisket flat. This lean side of the brisket looks thin and flat, totally different from the opposite side, which is the thicker, fattier side, called the point.

As a beginner, it’s easier to cook the whole brisket even though that might sound daunting. If the lean side or “brisket flat” is not cooked appropriately, it will dry out. After a few tries at the whole brisket, you’ll be ready to cook a brisket flat if you want to experiment with cooking smaller portions.

Grades of a Brisket

Generally speaking, beef has four grades from which to choose. From the least to greatest the meat grades are– Select, Choice, Prime, and Wagyu.

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wagyu-briskets at the grocery store
Wagyu Briskets at Costco

Even a select brisket is delicious, so don’t let that stop you from buying one. Until recently, everyone smoked select briskets because that’s all the grocery store carried. Now with more folks than ever turning to outdoor cooking as a hobby, the market is responding with higher grades of meat, which have greater deposits of fat within the muscle fiber.

This is called intramuscular fat and the better the grade, the more intramuscular fat will be in the meat. Intramuscular fat is discussed in a term called “marbling”, which means hidden lines of subcutaneous fat running throughout the uncooked beef, which resembles the veins in marble.

Better grades have more marbling even though all brisket has some marbling.

Close up of 15 pound brisket
Intramuscular fat can sometimes be seen within the meat fibers of smoked brisket.

Marbling is important because the fat breaks down into flavor and moisture and provides much of the juiciness in the brisket. The more juicy and flavorful the meat is, the better the brisket!

I recommend starting with select brisket and working your way up the available grades when you are ready. More experienced pitmasters should jump in wherever they feel comfortable.

Preparing Your Brisket For The Barbecue

Now that you’ve got your brisket home, you need to start preparing it to be smoked. The best way to prepare your beef brisket is to first chill it.

Chilling Your Brisket For Trimming (Optional)

Remove your brisket from its package and use paper towels to pat it dry. Place the brisket in the freezer for 30 to 45 minutes. After you’ve cooled the brisket, you’ll then want to trim it.

Trimming Your Brisket

Chilling your beef brisket before trimming it has been found to be the easiest thing to do for firm meat and fat that doesn’t slide around. Chilling it versus not chilling it just makes trimming easier, but feel free to skip the chilling step if you wish.

While fat is an advantage to having good-tasting brisket, you also don’t want to have an excess of fat. Excess fat will only make a mess of your smoker and anything more than 1/8 inch of fat will not render off during cooking.

So, a general rule of thumb is to trim this fat back to 1/4 – 1/8 inch.

You’ll need a few things before you start trimming:

●      Very sharp knife

●      Cutting board

●      Paper towels (if you skipped the chilling step)

●      Cold brisket

If you did not chill your brisket first, you’ll want to wet the paper towels and place them under the cutting board to keep the board in place while you’re trimming. You’ll find that a brisket at room temperature tends to move all over the place while you’re trying to trim so wet paper towels under the cutting board and also between the cutting board and brisket can help it stay stationary.

(You would think in theory a wet paper towel would move around but it actually locks things in place under the weight of the brisket.)

Trimming a brisket (the flat) with a sharp knife.

Using a very sharp knife (the sharper, the better…here is my favorite knife sharpener from our videos), begin to cut off any excess fat on your brisket. Trim the excess fat until completed.

There are different ways to trim a brisket, but the best way is dependent on the type of smoker you’re using. Even so, we’ll touch on the different ways here.

Fat Cap Side

The fat cap side is the side that has solid fat. This only needs to be slightly trimmed, if at all. If you choose to trim, leave at least ¼” of fat, especially if you’re using a pellet smoker because in a pellet smoker I recommend smoking it fat side down. I have a whole post on that here.

Meat Side

For the meaty part of the brisket, slice off the silver skin (it looks like a cloudy surface) and any hard fat (firm to the touch). This is so that you expose as much of the surface of the meat as you can to the smoke and it helps in turning your dry rub into nice bark.

Our dry rub will melt off any fat deposits as they melt away, so we want to give them actual meat to stick to. This will give you awesome flavor and the nice outer crust you see on good brisket.

Seasoning Your Brisket with Rub

You should use a dry rub on your brisket to help season and enhance the taste of the meat. There are plenty of store-bought options on the market, or homemade recipes for brisket rub. The rub you choose depends on what you like or what type of taste you’re in the mood for and could depend on a combination of things you are looking for in your cook.

Will children enjoy this brisket or will it be too spicy? Do I want to try a traditional Texas-style brisket or would I like a sweet rub? Do I want to develop my own signature flavor or use a celebrity pitmaster’s recipe until I am ready?

Seasoning the brisket with dry rub

For your first time, we recommend you try our award-winning recipe for brisket rub which we keep right here.

Here are some other options:

●      If you really want to taste the flavor of the beef, a combination of kosher salt and black pepper (a dalmatian rub or Texas-style brisket rub) is a smart choice.

●      Other times you may want more flavor and decide to add to the dalmatian rub by adding a touch of garlic and onion powder.

●      Store-bought rubs are also good options. They’ll come with ingredients like brown sugar, paprika, jalapeno powder, etc.

There’s no best way to do a rub for your brisket. So, we suggest you try out different rubs each time you smoke and let your family decide on their favorite!

It’s difficult to instruct how much rub to put on your brisket. Adding too much will keep the smoke from penetrating past a heavy layer of spices so you don’t want to overindulge. The whole purpose of smoked brisket is to have excellent smoke flavor.

A good rule of thumb is about 1/4-1/2 c. of barbecue rub seems to make the best brisket. Remember you want to still see the meat after the rub is applied.

As far as any other seasonings like mustard slathers, we feel these are unnecessary, but many people use a thin coat of yellow mustard because they feel this helps the rub to stick to the meat. Mine always sticks anyway but to each their own.

You’ll find smoking barbecue is so addictive you’ll try a million different techniques just to satisfy your curiosity!

How Long Do You Smoke a 15 Pound Brisket?

You smoke a 15 pound brisket for 15-20 hours at 225 degrees.

We will wrap the brisket in pink butcher paper when the internal temperature of the meat hits about 170 degrees, and then remove the brisket from its final cook when the internal temperature reaches 195 degrees. Finally, we will let the brisket rest for 1-4 hours.

Smoking your brisket at around 225 degrees is the best cooking temperature because you want the smoker temperature to be low for breaking down connective tissue.

Let’s get one thing straight. Brisket begins as a tough cut of meat.

It’s not like a NY strip that starts tender and if you cook it wrong it becomes tough.

It is tough to begin with and slow cooking, via your barbecue smoker, breaks down the connective tissue present in the muscle that is responsible for this toughness (which is experienced in difficulty in chewing).

Tough brisket is a result of not giving the brisket enough time for these tissues to melt and break down, not a result of too much heat or too much cooking time, as can be the case with a tough steak.

Cooking the brisket at a low temperature allows it to cook slowly at the optimum temperature for breaking down the connective tissue, resulting in a tender brisket.

As the brisket cooks it will gradually get more and more tender, with the brisket rest being the final assault on all of that connective tissue.

Meater Thermometer

Don’t Forget the Meat Thermometer:

Make sure you use a meat thermometer to monitor the internal temperature of the brisket so that you can wrap and pull the brisket from the heat at the right time for each step in the process.

The thermometer should be placed into the thickest part of the meat, in the “point” of the brisket, which is the thicker side. Some people chose to place a thermometer in the point and the flat, so they can get readings on both sides to further their brisket data and research.

If your smoker doesn’t come with a thermometer, you’ll want to invest in one and we recommend the classic barbecue brands ThermoPro or Meater Thermometer. These brands will last for years if not a lifetime and you will see all of your favorite barbecue personalities using these brands because they are durable and reliable.

(Many pellet grills and an electric smoker come with temperature probes for this purpose and can be used to monitor your meat temperature.)

Make sure to place a water pan in the chamber of your barbecue smoker to encourage humidity, which assists in creating good smoke flavor and helps keeps the meat juicy.

Wrapping Your Brisket

Once you see the internal temperature reach 170 degrees, you’ll want to take your brisket off the smoker to wrap it. You don’t have to wrap your brisket and it may still come out tender…some people find that it messes with the quality of their bark, but we have found that the benefits far outweigh the issues.

For wrapping, you have your choice between butcher paper and aluminum foil.

a brisket wrapped in butcher paper

Feel free to use aluminum foil to wrap your brisket, but again we’ve found that butcher paper works best because it’s a more breathable and porous material. Wrap your brisket twice using two layers of paper and secure it with a little tape. After it’s wrapped, place it back on the smoker and let the cook time continue.

What Temperature is a Brisket Done At?

A brisket is done when the internal temperature reaches 190-203 degrees.

For best results, become familiar with how the brisket looks and feels when poked with a gloved finger.

completed brisket 15 pounds- with bark on a cutting board
Completed 15 lb brisket

This won’t mean much on your first smoked brisket, but a year from now you’ll know by how it looks, the color, the size of the brisket, and how much it bounces back when touched, if the meat should go a bit longer or if it’s ready to come off the pit.

But, removing it between 190-203 degrees and letting it rest insures a great quality brisket.

How Long Do You Rest a Brisket?

You rest brisket for 1-4 hours in the butcher paper, wrapped in a towel to maintain warmth.

Old barbecue pros know that this is arguably one of the most important things you can do to further break down any residual connective tissue. This results in tender brisket that drapes over an outstretched finger.

Additionally, the juices will evenly distribute throughout the wrapped brisket while it rests…if you slice the meat hot, you’ll lose plenty of this delicious juiciness as it runs out all over your cutting board and probably onto your kitchen floor.

Sliced brisket ready for a party
Sliced brisker ready for a party.

You’ve worked a long time for the perfect brisket and it’s time to finish strong. We know it smells divine but let that thing rest!

For our smoked brisket recipe and all of our other barbecue secrets, we’ve set up these helpful links for you. You can also see all of our posts on brisket in the Brisket School category at the top of this website.

Comment below if you need help from me (Chef Sarah) or the team! Happy Barbecuing!

Have questions? Need help? Have an addition or a suggestion to a recipe? Drop me a comment below!

If you make this recipe, I would LOVE to see it!

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Sidney Carter

Friday 14th of July 2023

The fat on a brisket up or down on the grill

Sarah Penrod

Wednesday 19th of July 2023

Hi Sidney! There is much debate on this but my personal preference is to put the fat side down on our grill/smoker.

Our pellet smoker has the heat source at the bottom much like a Green Egg or Kamado Joe has so we use the fat to shield the brisket and keep it from drying out.

Even if the heat source was on the side, I'd still go fat side down.

Let me know if you have any other questions! :)

Erika Rose

Thursday 15th of June 2023

Im making a brisket for the first time this weekend. I want to inject. Do you have any recipes for the injection that use gluten free ingredients? Wish me luck - I am so nervous to screw it up. 18 lb SRF waygu brisket - hope its delicious!

Thanks Erika

Sarah Penrod

Friday 16th of June 2023

You can use gluten free beef broth and get really good results but to be honest wagyu brisket is so fatty and delicious you are going to have tons of flavor from that! I wouldn't add much to wagyu.