Talking Turkey: Thanksgiving Dinner Energy Use and Carbon Dioxide Emissions

Thanksgiving is one of the most wonderful time of the year, when families gather and spend time together while the smell of turkey seeps in from the other room. You’ve probably never given much thought to the energy use or environmental impact behind that intoxicating turkey smell coming from the kitchen, and in fact the country’s overall energy use drops on Thanksgiving because the increase in kitchen power use is offset by the drop in energy use from office and commercial buildings that are closed for the holiday.

However it’s always interesting to look at the actual energy numbers behind various regular activities and consider if there’s a way to do it better. Especially these days when online cooking forums and the Food Network is constantly making it trendy to cook your Thanksgiving turkey in new and novel ways. Your grandmother’s recipe isn’t the only one in town anymore (though I’m sure it’s still the best). Those cooking the turkey now have deep fryers and smokers, while Turducken is being eaten by NFL players after the Thanksgiving Day games.



With so many new cooking methods for Thanksgiving dinner, it got me to wonder what the energy cost was to cook turkey using these different methods. While there were investigations on the total energy use across the country to cook Thanksgiving dinner (linked later in this article), I could not find anything about the energy cost or associated carbon dioxide (CO2) emissions of an individual turkey cooked using different methods, so I thought I’d run through them myself!

Recipes

After searching across the Internet, I settled on seven different methods to cook your Thanksgiving turkey– the traditional roasting of a turkey and six newer and trendier options that the hip or contrarian chef might utilize. These seven methods are the following:
  • Roasting;
  • Braising;
  • Deep frying;
  • Grilling;
  • Smoking;
  • Spatchcocking; and
  • Sous vide.

For each of these cooking methods, I’ve sought out a recipe either from a well-known chef of repute or directly from the manufacturer of the turkey or the cooking apparatus in question. By using these recipes, ideally these authorities will have an air of authority to them. Because each recipe offers cooking times based on various size turkeys, this analysis will normalize each recipe for a standard 15 pound (lb) turkey as the size recommended for a dinner of 12 people.

If you want to skip the details of the recipes and the calculations, click here to go straight to the results!
 
Note: For all of the below recipes, there are additional energy consuming steps that are not going to be included in the calculations. These steps include removing turkey from the oven to baste, pre-refrigeration, sauteing after the turkey is fully cooked to get crispy skin, etc. The point is the calculations below will focus on the energy needed to fully and safely cook the turkey, and any energy used before or after that process will be ignored for simplicity and uniformity. Of course you will be making side dishes and putting on finishing touches, so your mileage WILL vary compared with what is calculated here. The goal of this exercise is just to get a back-of-the-envelope approximation for how the different cooking methods affect the energy required– they are definitely not going to be exact or completely robust. You’ve been warned! 

Roasted turkey

Since this is the traditional cooking method, it seemed criminal to use a recipe other than the one championed by Julia Childs. Her traditional recipe for a 10 to 13 pound turkey calls for the oven to be preheat to 450oF and then the turkey roasted for 30 minutes before reducing the oven to 350oF and roasting for another 2 to 2 hours 30 minutes.
Normalizing for a 15 lb turkey, we’ll use the higher time estimate and add 15 minutes for the extra weight and say the turkey will be cooked in the oven for 3 hours 15 minutes.

Braised turkey

 Braised turkey is a great segue from the traditional to the more novel turkey-cooking methods, as it doesn’t stray too far from the original whole turkey roasting method. You are still cooking the turkey fully in the oven, but with the main difference that the turkey is sitting in a pan of vegetables and stock to bring in more moisture to your turkey.

For the braised turkey, we’ll stay with household names and use Bobby Flay’s recipe for herb roasted and braised turkey. This recipe calls for an oven preheated to 450oF with the 17 pound turkey and a bed of vegetables cooked for 45 minutes before the temperature is reduced to 350oF and cooked an additional 2 to 2 hours 15 minutes longer (while basting with warm chicken stock). After the whole bird is cooked, the legs are removed and braised in a roasting pan with stock for an additional 1 hour at 350oF.

To normalize to a 15 pound turkey, we’ll say the braised turkey cooks in the oven for a total estimated cook time of 3 hours 30 minutes.

Deep fried turkey

If you can manage to get it done without an explosion or trip to the hospital, deep frying turkey has become one of the more exciting and talked about cooking alternatives. Bobby Flay’s colleague at Food Network, Alton Brown, has one of the most used deep fried turkey recipes for those who love the science and Internet-trends of cooking.

For a 13 to 14 pound turkey, Alton has you heat up a 28 to 30-quart pot of oil to 250oF, add in the turkey and raise the temperature to 350oF, and once at that temperature cooking for 35 minutes.

To account for the weight of a 15 pound turkey, we’ll say this recipe cooks with a propane heater for a total of 40 minutes.

Grilled turkey

The grilled turkey recipe chosen comes straight from Butterball, the turkey supplier that accounts for 20 percent of total turkey production in the United States. Among grilling aficionados, the debate to grill by charcoal or by gas is one of the most heated. In addition to differences in taste, ease, and convenience, the choice of grill type also affects the end energy use to cook. Luckily for us, Butterball provides instructions for both a charcoal and gas grill.

Butterball’s recipe for charcoal grilling says that the 10 to 16 pound turkey will be cooked over 50 to 60 charcoal briquettes (after those initial briquettes have been burned for 30 minutes). At that point, the turkey is to be placed on the grill for 2 to 3 hours, with 12 to 16 briquettes being added every 45 minutes to 1 hour. To normalize at the 15 pound turkey, we’ll estimate that initially 60 charcoal briquettes will be used and, during the cooking process, 50 more briquettes will be added for a total cooking fuel of 110 charcoal briquettes on a charcoal grill over the course of 3 hours.

Butterball’s recipe for gas grilling says the same 10 to 16 pound turkey is cooked over indirect heat (after 10 to 15 minutes of preheating) at 350oF for 2 to 3 hours. For the 15 pound turkey we’ll assume the turkey is cooked on a gas grill at 350oF for the whole 3 hours.

Smoked turkey

Where deep frying or grilling the turkey may have once held the title as the ‘macho’ way to prepare a Thanksgiving turkey (whatever that may mean), smoking the meat might just have taken that crown. Using lower heat over longer periods of time, smoking turkey evokes the expert barbecue pit masters of the country to impart full flavor without drying out the turkey. Butterball once again provides authoritative guidance to smoking your Thanksgiving dinner, again allowing the consideration of two different fuel types.

Butterball’s recipe for preparing a turkey in a water smoker uses 10 pounds of charcoal briquettes (pre-burned for 30 minutes) to start the cooking process, adding in 12 to 14 more charcoal briquettes every 1 hour 30 minutes to ensure the temperature remains at 250oF through a total cooking time of 6 to 10 hours for a 12 to 18 pound turkey. For our 15 pound turkey, we’ll call that cooking fuel of 10 pounds plus 70 briquettes of charcoal over a cooking time of 8 hours in the water smoker.

When using an electric smoker, Butterball’s recipe calls for the smoker to be set at 225oF and the 8 to 18 pound turkey to be cooked for 8 to 12 hours. Normalizing to our 15 pound turkey, we’ll say the final cook time is 11 hours at 225oF in the electric smoker.

Spatchcocked turkey

If Julia Child was the first queen of celebrity chefs, Martha Stewart eventually took her crown, and so we have to include a recipe of Martha’s.  Martha Stewart’s magazine featured a recipe for a spatchcocked turkey, a method of cooking poultry in which bones are removed so the bird can be flattened and cooked more evenly and quickly.
Martha Stewart’s recipe has the oven preheated to 450oF, with a 12 pound and fully spatchcocked turkey roasted for 1 hour 10 minutes. For our 15 pound turkey, we’ll adjust this to be cooked in the oven at 450oF for 85 minutes.

Sous vide turkey

Sous vide cooking, or the process of cooking food that is vacuum-sealed in a plastic pouch by placing it in heated and circulating water bath, has been around for decades. The method has gained traction more recently, however, as home cooks are increasingly getting their hands on the cooking equipment necessary that was previously only available in professional kitchens. The cooking method allows meat to be cooked at lower temperatures and thus cooked more evenly, safely, and while retaining moisture.

If you are in the market for a sous vide immersion circulator, one of the first places you might go is Williams Sonoma. To aid the new owners of this equipment, they also offer up a sous vide turkey recipe by Michael Voltaggio. The water of the sous video immersion circulator is preheated to 150oF and the vacuum sealed turkey pieces then placed in and cooked for 2 hours 30 minutes.

Calculations

These recipes use a wide variety of cooking apparatuses and fuels, so the methodology of calculating the total energy use and associated CO2 emissions will vary. Much like the Halloween-themed post on the most sustainable way to light your Jack-O’-Lantern, this post will thus be calculating very rough estimates using educated choices of data and assumptions. The final numbers should be considered back-of-envelope calculations and not scientifically or rigorously tested. There are also various aspects to the cooking process that would impact the end result that will not be accounted for, as well as variables to your individual cooking efforts that would change the final result (e.g., size of oven or grill, the energy mix of your power supplier, what type of propane or charcoal you buy from the store).

All that said, if you have ideas or suggestions on how to refine any of the numbers calculated here, then please reach out and/or leave a comment! (For one, I’ve assumed an oven is using a uniform amount of power regardless of the temperature at which it is set. While the difference of power use at 350oF and 450oF is not likely that much, it is definitely measurable. However, after much digging I was still unable to find any way to estimate the power difference among different temperatures, so a uniform power consumption was chosen and used for all use of the oven.)

Regardless of fuel type, all final energy numbers are calculated in kilowatt hours (kWh) and all CO2 emissions are calculated in lbs.

If you don’t care about going through the calculations and just want to jump to the final numbers, click here to jump to the results!



Roasted turkey

We are assuming the use of an oven for 3 hours 15 minutes. The oven will also need to preheat the oven, which we’ll assume to take 15 minutes. All together, the energy use and CO2 emissions will be associated with using an oven for a total of 3 hours 30 minutes.

In the United States, ovens are commonly powered by either electricity or by natural gas (though electric stoves are almost twice as common as gas stoves). The fuel type will affect the end energy use and CO2 emissions:
Electric oven:

Electric ovens use about 2.0 kilowatts (kW) of power. Assuming this power usage for the entirety of the recipe, the energy use of roasting the turkey in an electric oven is about 2.0 kW times 3.5 hours, or 7.0 kWh.

The latest data available from the Department of Energy says that for every kWh of electricity produced in the United States, 1.096 pounds of CO2 are released. Thus for this recipe in an electric oven, the CO2 emissions are equal to 1.096 lbs/kWh times 7.0 kWh or about 7.7 pounds of CO2.

Electric ovens use about 2.0 kilowatts (kW) of power. Assuming this power usage for the entirety of the recipe, the energy use of roasting the turkey in an electric oven is about 2.0 kW times 3.5 hours, or 7.0 kWh.

The latest data available from the Department of Energy says that for every kWh of electricity produced in the United States, 1.096 pounds of CO2 are released. Thus for this recipe in an electric oven, the CO2 emissions are equal to 1.096 lbs/kWh times 7.0 kWh or about 7.7 pounds of CO2.
Gas oven:

Gas ovens use about 0.112 therms of natural gas per hour. Over the course of the 3 hours 30 minutes, this would result in the use of 0.392 therms. In order to convert this amount of natural gas to kWh for comparison’s sake, we use the energy equivalence of one therm being about 29.3 kWh, meaning the energy use of a gas oven for this recipe is 11.5 kWh.

The Environmental Protection Agency (EPA) has a handy carbon footprint calculator you can use to analyze the CO2 emissions of all sorts of household activities. Included among its assumptions is the emission factor of cooking with natural gas, at 11.7 lbs of CO2 per therm of natural gas (this is another place where your specific situation may vary– some gas stoves use propane or other flammable gases as fuels, but we’ll assume natural gas for the sake of this calculation). Based on this assumption, the roasted turkey recipe in a gas oven would result in CO2 emissions of about 4.6 lbs of CO2.

Braised turkey

The braised turkey recipe also uses a oven, but this time for 15 minutes of preheating and 3 hours 30 minutes of cooking for a total of 3 hours 45 minutes. Again, this process can be done in an electric or a gas oven using the same assumptions as the roasted turkey.

Source

Electric oven:

Using the same assumptions as above for 3 hours 45 minutes of 2.0 kW power usage, the braised turkey recipe uses 7.5 kWh. Using the same assumption of 1.096 lbs of CO2 per kWh results in the CO2 emissions of the braised turkey in an electric oven being about 8.2 lbs.

Gas oven:

Repeating the assumptions above again gives an approximate energy use of 0.420 therms, or 12.3 kWh, and would result in emissions of about 4.9 lbs of CO2.

Deep fried turkey

The deep frying recipe calls for a propane heater to preheat a pot of oil to 250oF, adding in the turkey and raising the temperature to 350oF, and then cooking for 40 minutes.
 

The assumptions we can make here are that a propane cooker uses 65,000 British thermal units (BTUs) per hour and preheating deep fryers takes about 30 minutes. That means the total energy use would be 65,000 BTU/hour times 1 hour 10 minutes for a total of 75,833 BTU. Converting the propane use in BTU to approximate energy use in kWh gives a final result of approximately 22.2 kWh.

To calculate the CO2 emissions from this cooking process, the EPA’s carbon footprint calculator again gives us the needed information of CO2 emissions for cooking by propane. With the EPA assumption that every million BTU of propane burned emits 136.05 lbs of CO2, the deep fried turkey’s 75,833 BTU emits about 10.3 lbs of CO2.

Grilled turkey

Charcoal grill:

When the grilled turkey recipe for a charcoal grill is used, 110 charcoal briquettes are used over the course of 3 hours (after 30 minutes of pre-burn of charcoal).

Experiment shows that the energy content of charcoal is 7.33 kilojoules (kJ) per gram, while a single briquette of charcoal weighs about 25.7 grams. All together, this means a charcoal grilled turkey takes 20,733 kJ, which is converted to about 5.8 kWh.

For the CO2 emissions of charcoal grilling, Oak Ridge National Laboratory has found that the amount of charcoal needed to operate a grill for an hour emits 11 pounds of CO2. For this recipe that uses the grill for a total of 3 hours 30 minutes, that amounts to 38.5 pounds of CO2.
Propane grill:

When prepared on a gas grill, propane is needed to preheat for about 15 minutes and then cook the turkey for 3 hours.

The rate of propane use in propane grills varies, but a standard gas grill is rated at about 36,000 BTU/hour. That means for the full 3 hour 15 minute operation, the Butterball grilled turkey recipe requires 117,000 BTU or approximately 34.3 kWh of energy.
 
As with the recipe for deep fried turkey, we can use EPA’s assumption that every million BTU of propane burned emits 136.05 lbs of CO2, meaning this propane grilled turkey accounts for 15.9 lbs of CO2.

Smoked turkey

For the smoked turkey recipe, we again have two options for cooking fuel– either a charcoal fueled water smoker or an all electric smoker.

Charcoal powered water smoker:
This recipe required the burning of 10 pounds plus 70 briquettes of charcoal for 8 hours (after 15 minutes of preheating).
Using the same assumptions as with the charcoal grilled turkey, we find that at 7.33 kJ/gram of charcoal and 25.7 grams of charcoal per briquette gives a total energy use of the charcoal for a turkey smoked with a water smoker of about 12.9 kWh.
For the CO2 emitted, we again assume that grilling for an hour emits 11 pounds of CO2 per hour, meaning for a total grill time of 8 hours 15 minutes we get 90.8 lbs of CO2.
Electric smoker:
The electric smoker will be set at 225oF and the turkey cooked for 11 hours. Common electric smokers are rated at about 800 Watts, meaning 11 hours of use would use 8.8 kWh.
Since this is all electric, we can reuse our assumptions from cooking in an electric oven. Assuming 1.096 lbs of CO2 are released for every kWh of electricity produced in the United States, the electric smoker would account for about 9.6 lbs of CO2.

Spatchcocked turkey

The recipe for spatchcocked turkey brings us back to the oven, but with the distinct (and intentional) advantage of a greatly reduced cooking time compared with the other methods. The 15 pound turkey will cook in the oven at 450oF for 85 minutes, after 15 minutes of preheating, for a total oven use time of 1 hour 40 minutes.
Electric oven:
Reusing our electric oven assumptions, 1 hour and 40 minutes of 2.0 kW power usage means the spatchcocked turkey will require about 3.3 kWh of energy. At 1.096 lbs of CO2 per kWh, that means the recipe accounts for about 3.6 lbs of CO2.
Gas oven:
If instead the spatchcocked turkey is cooked in a gas oven, which uses 0.112 therms of gas per hour, the energy use of this recipe would be about 5.5 kWh, while the CO2 emissions associated with this cooking process would be 2.2 lbs.

Sous vide turkey

Last but not least is the sous vide turkey, which requires the use of an immersion sous vide immersion circulator for 2 hours 30 minutes (after a 15 minute preheat time). Given that the power rating of a sous vide from Williams Sonoma (the source of our recipe) is 1,100 W and the total operating time is 2 hours 45 minutes, the electricity use comes out to about 3.0 kWh. At 1.096 lbs of CO2 per kWh, that means the sous vide turkey accounts for about 3.3 lbs of CO2.

Graphical results and conclusions

With all those calculations and assumptions out of the way, we can finally look at all the results in one table:

Click to enlarge

These numbers can also be displayed graphically to show the overall level of ‘green-ness’ of each cooking method:

Click to enlarge

Looking at these results, there are a number of points of interest and interesting conclusions to draw:
  •  In terms of the amount of CO2 emissions, the two options that use charcoal (smoked in a charcoal smoker and grilled on a charcoal grill) are by far the greatest emitters. This result shouldn’t be surprising, as charcoal (with anthracite coal as one of its ingredients) is one of the more carbon intensive fuels you can use in your homes. However it is interesting to note that, despite their higher CO2 emissions, they are in the same ballpark in terms of energy use as the other cooking methods. This result shows how charcoal is an efficient fuel source, it just happens to also be dirty.
  • In terms of the total energy use, the two options that use propane (deep fried and grilled on propane grill) require the greatest energy. The higher energy needed is likely due to the cooking source being less efficient than others, with gas/propane burners typically being only 40% efficient with the remaining 60% of energy output being lost to heating the surrounding air or as visible light.
  • The two best cooking methods in terms of both minimal energy use and CO2 emissions are the sous vide turkey and the spatchcocked turkey (in either a gas or electric oven). The reason these reign supreme is telling, and different for the two of them.
    • For the sous vide turkey, the turkey is vacuum sealed and cooked in heated water the size of a typical pot. The result is that a smaller volume has to be heated up when compared with a larger oven, deep fryer, smoker, or grill that needs to heat up and keep heated the larger surrounding area. By focusing the heat in a smaller area, the total energy use is greatly reduced. In all cooking, the smaller the area you are heating up the more energy efficient the cooking process will be, which is why it is actually advisable to cook using smaller, dedicated appliances (e.g., toaster ovens, panini press, etc.) than to use the oven or stovetop for everything.
    • For the spatchcocked turkey, the reduced energy use and associated CO2 emissions is simply attributed to the largely reduced cooking time. Outside of the deep fried recipe, which uses the aforementioned inefficient propane, the spatchcocked recipe is the only one that takes under two hours of cooking. Obviously, the less time you have to have your appliances working, the less energy you’ll use. So while spatchcocking may have become popular due to the convenience of reduced cooking time, the relative efficiency is also among its virtues.
  • When comparing the recipes that use either the gas oven or the electric oven, the final figures show that the gas ovens use more energy but emit less CO2. What is important to note about the CO2 difference, however, is that the numbers are based on the average U.S. figure for CO2 emitted per kWh. This number can vary greatly depending on your power company and where you live. For example, if you live in Vermont then your power likely comes from a greater proportion of renewable energy than in other states, which would reduce the relative CO2 emissions of your electric oven. Of course the opposite is true if your power company uses more coal in its fuel mix than the national average.
  • One last point is that the relative energy use here does not correlate to the relative cost to the consumer for preparing the turkey. Certain fuel types are much cheaper than others, which is part of the reason they are popular to use in the first place. For example, just because grilling by propane uses almost six times the energy as grilling by charcoal, the relative prices of the fuels actually results in grilling by gas being less costly per hour for a consumer.

According to the National Turkey Federation, 46 million turkeys are roasted each Thanksgiving. Various outlets have attempted to estimate the actual energy use of those turkeys cooked in aggregate, with answers ranging from 48 million kWh to 792 million kWh (quite a wide range, showing just how uncertain the true number is). Using the numbers calculated here, if all 46 million turkeys were cooked sous vide then that would be 138 million kWh, whereas if they were all grilled on a propane grill then that would be over 1.5 billion kWh. Concerning CO2 emissions, the 46 million turkeys could account for 152 million lbs (sous vide) or over 4 billion lbs (grilled on charcoal grill)– for context, a passenger vehicle emits about 10,000 lbs of CO2 per year. That’s all to say, the small decisions everybody makes individually can add up to make a large difference in total energy use or CO2 emitted– even when talking turkey.

In the end, though, there isn’t too much reason for you to stress. There are plenty of methods you can use to cut down on energy use while cooking if you choose to do so(see some examples here and here, or you can even invest in a solar cooker that uses just the sun and reflectors to cook at temperatures up to 400oF!). But again, the overall energy use on Thanksgiving is lower than the average Thursday. It’s a time to relax and be grateful, not necessarily to measure out your exact briquettes to minimize energy spent. But you can come to the Thanksgiving table with some of these fun facts handy to impress your family, just be sure to praise the cooking of the chef first– he or she spent plenty of time making that dinner!

Have a happy Thanksgiving!

Sources and additional reading

About the author: Matt Chester is an energy analyst in Washington DC, studied engineering and science & technology policy at the University of Virginia, and operates this blog and website to share news, insights, and advice in the fields of energy policy, energy technology, and more. For more quick hits in addition to posts on this blog, follow him on Twitter @ChesterEnergy.  

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