Smoker Time and Charcoal Calculator

How the calculator works

This calculator plans the fuel for a smoke and tells you the temperatures to hold. It does not predict how long your meat will take, and the reason is in the source. The USDA does not publish smoking times by weight. It says cooking time depends on the type of meat, its size and shape, the distance from the heat, the temperature of the coals and the weather, and that it can take anywhere from 4 to 8 hours.

So you choose the hours, and the calculator works out the charcoal from the USDA’s two rules:

charcoal smoker: briquettes to add = hours x 15

covered grill: briquettes = 50 to start + hours x 10

It then shows the air temperature to keep in the cooker and the safe internal temperature for what you are smoking.

Worked example

You are smoking a pork shoulder in a covered kettle grill and allowing 6 hours.

1. To start: about 50 briquettes.
2. To add: 6 x 10 = 60 briquettes, about 10 every hour.
3. Total: 50 + 60 = 110 briquettes.
4. Air temperature: 225 to 300 °F for the whole cook.
5. Done at: 145 °F inside, then a rest of at least 3 minutes.

The same 6 hours in a charcoal smoker: 6 x 15 = 90 briquettes to add, on top of the first load, which follows the maker’s directions for your model.

If you plan for the full 8 hours, that is 130 briquettes in a covered grill and 120 added in a smoker. Buy for the long end. Running out of charcoal in hour six is the one problem you cannot fix from the patio.

Setting up a charcoal smoker

The USDA’s directions:

1. Follow the manufacturer’s directions for lighting the charcoal.
2. Let the charcoal get red hot with gray ash. That takes about 10 to 20 minutes, depending on the quantity.
3. Pile the charcoal around the drip pan and fill the pan with water, to keep the air inside moist.
4. Add about 15 briquettes every hour, and check each time that the drip pan still has water in it.

The drip pan does two jobs. It catches fat and juices so they do not flare up on the coals, and the water keeps the environment moist.

For smoke flavor, the USDA says the most satisfactory results come from hickory, apple or maple wood chips or flakes. Soak the chips in water first to prevent flare-ups, and add about 1/2 cup of chips to the charcoal as desired.

Smoking in a covered grill

You do not need a dedicated smoker. A covered grill works with a pan of water under the meat.

1. Pile about 50 briquettes in the center of the heat grate.
2. When they are covered with gray ash, push them into two piles.
3. Center a pan of water between the two piles.
4. Put the food on the grill over the water pan.
5. Close the lid and keep the grill vents open.
6. Add about 10 briquettes every hour to maintain the temperature.

The water stops flare-ups when fat drips, and the USDA notes that steam from the water helps destroy harmful bacteria.

Two thermometers

The USDA says you need two types of thermometer to smoke food safely: one for the smoker and one for the food.

The smoker thermometer reads the air inside. It has to stay between 225 and 300 °F throughout the cooking. Many smokers have one built in.

The food thermometer reads the inside of the meat. An oven-safe thermometer can stay in the meat during smoking. An instant-read thermometer is used after the meat is taken out.

Before the meat goes on

Thaw completely. Smoking cooks at low temperatures, so meat that goes on frozen takes too long to thaw in the smoker and lingers in the range between 40 and 140 °F where harmful bacteria can multiply. Thaw in the refrigerator, and cook or refreeze within 1 or 2 days. The defrosting time calculator on this site gives the days by weight.

Marinate in the refrigerator, never on the counter. If you want some of the marinade for basting or as a sauce, set a portion aside before the raw meat goes in. Marinade that has held raw meat has to be boiled before it touches cooked food.

Partial cooking. Some people start meat in the microwave or on the stove to shorten the smoke. Only do that if the food goes immediately from there to the hot smoker.

After the smoke

Refrigerate meat and poultry within 2 hours of removing it from the smoker. Cut it into smaller portions or slices, put it in shallow containers, cover and refrigerate. Use it within 4 days, or freeze it.

Tips and common mistakes

Do not smoke in makeshift containers. The USDA warns against galvanized steel cans and other materials not intended for cooking, because of chemical residue.

Set the cooker in a well-lit, well-ventilated place, away from trees, shrubbery and buildings. Use only approved fire starters, never gasoline or paint thinner.

Do not trust the clock. Four to eight hours is a wide range, and the weather alone can move you within it. Check the meat with the thermometer.

Check the water pan every time you add charcoal.

Sauce late. Apply sauce in the last 15 to 30 minutes so it does not burn.

Count the charcoal before you light it. Divide the bag into hourly piles of 10 or 15, and you will know at a glance whether you have enough to finish.