Why are we doing this?


At Burger King, we’ve been working on finding scalable solutions to tackle the climate impact of the food we produce and deliver to guests around the world everyday. To do it right, we started with understanding the facts.

Livestock is responsible for 14.5% of all human-induced greenhouse gas (GHG) emissions, according to estimates from the Food and Agriculture Organization of the United Nations (FAO), and beef production accounts for 41% of those emissions.

Beef Emission

What contributes to beef production’s large footprint?

In our research and discussions with stakeholders globally, we’ve learned that the issues around climate and beef production are complex. There are actually several sources of greenhouse gases (GHGs) along the beef supply chain before it reaches your plate, so when it comes to reducing emissions from the beef supply chain, there are a lot of places where we could step in.

We decided to start with tackling cows’ enteric fermentation and their methane emissions.

What does this mean?

Cows have a complex digestive system consisting of four stomachs, which enables them to eat and digest food that we cannot – such as grass – through a process called enteric fermentation. As the cows digest their feed, they produce a lot of methane. This greenhouse gas is released every time the cows burp and fart the methane gas out. Methane is considered a high contributor to global warming, making it a key area for us to tackle in pursuit of the 2016 Paris Agreement target of limiting global warming to well below 2°C and pursuing efforts to limit it to 1.5°C.

Explore the key sources of GHG emissions
along the beef supply chain below.


"Beef is one of the top commodities that we buy at Burger King. We also know that cattle are one of the top contributors to overall greenhouse gas emissions, so our job is to understand how we can continue to grow our business while still reducing the emissions from cattle over time."

Matt Banton, Head of Innovation and Sustainability, BK

What did
we do to help?


From chamomile tea to baking soda, humans have used natural remedies to help with digestion-related challenges for centuries. So, what if the same natural remedies that help people take care of their stomach aches can help to reduce the impressive amounts of gases cows produce every single day? We teamed up with top level scientists in the US and Mexico to study different herbs, like chamomile, cosmos bipinnatus and lemongrass, in order to find a solution that could potentially benefit the environment and the millions of people that simply love meat.

A new diet for cows that could help them digest better and release less methane.

As a result, we found that by adding 100 grams of dried lemongrass leaves to the cows’ daily feed, we were able to see a reduction of up to 33% on average of methane emissions during the period the diet was fed (the last three-to-four months of the cow’s life in the case of our research). And the good news is that this reduction was powered by a natural plant that grows from Mexico to India.

How was the methane-fighting potential of lemongrass discovered?


Teaming with top researchers from the Autonomous University of the State of Mexico and U.C. Davis, we’ve conducted several rounds of research developing and refining a new cattle menu. The results? Based on this initial research, we’ve discovered that feeding cows with relatively small amounts of lemongrass, during the three-to-four month ‘fattening’ stages of production, reduces their methane emissions by up to 33% on average. Adding 100 grams of dried lemongrass leaves to the cows’ daily diet makes a significant difference.

Click on any of the buttons below to learn more about each stage
in the research journey so far:

We continue to partner with higher education institutions and industry scientists to conduct additional research on this topic and will periodically report on our findings.



"RBI’s Sustainability strategy is grounded in one simple principle - doing what's right. And this project is a really good example; it's a scalable solution to help reduce methane emissions."

Jose Cil, CEO, RBI

How can we work together?


We know our own supply chain is just a small piece of the overall puzzle and we can't do this on our own. It is only when these solutions are widely adopted by the beef industry that we can make a tangible positive impact.

That’s why we are making the Cows Menu formula open source and free for all to use.
We teamed up with scientists to create a formula, making it and our supporting research publicly available so that every fast food brand, meat supplier, and farmer can replicate, test and refine it. If we all work together as an industry to develop and adopt open source solutions such as the Cows Menu formula, we can aim to tangibly reduce methane emissions and develop concrete actions on climate change that aspire to the United Nations Sustainable Development Goals for 2030.

This is all part of our beef sustainability strategy. We’re improving our beef sourcing approach, promoting best practices at all levels of the supply chain, and driving creative solutions through research and collaboration.

We’ve made the formula and supporting research publicly available so that every fast food brand, meat supplier, and farmer can use it. By working together and getting the whole industry to adopt the open source formula, we can potentially reduce methane emissions.

How to implement
the formula?


Burger King recognizes that global beef production and consumption have considerable climate impact. But we equally know that farmers and ranchers around the world care deeply for their land and their animals. As a large global buyer of beef, we want to support our value chain partners in implementing more potentially ‘climate friendly’ agricultural practices while understanding that they are limited in resources and capacity, and are balancing day-to-day business and sustainability challenges.

We’re excited to introduce industry partners and peers to the Cows’ Menu initiative, which has the potential to reduce the beef industry’s climate impact. After a year of trials and research with scientists at the Autonomous University of the State of Mexico and U.C. Davis, we were able to find a formula for cows’ daily feed made with lemongrass leaves, which suggests a reduction of methane emissions by up to 33% on average during the cow’s last 3 to 4 months of life. The formula is an all-natural supplement to the daily feed ranchers are already using – which based on the research to date, has the potential to be a tangible and achievable solution.

The following “How to” guide takes you step-by-step through the open source formula and the FAQs include all the details to implement the Cows’ Menu initiative in your farming practices and supply chain.

The more ranchers who use it, the more we can learn about the potential of this solution. As we refine, gather learnings and scale the Cows’ Menu initiative we hope to make a tangible difference in helping to mitigate climate change.


For additional information on the
Cows Menu program,
please reference our FAQs.


"After testing the addition of 100 grams of lemongrass we observed a reduction of up to 33% on average in the daily emissions of methane."

Octavio A. Castelán Ortega, Professor, Autonomous University of the State of Mexico

What are
the opportunities
to scale?


We’re optimistic that peers and supply partners will take advantage of the lemongrass supplement formula, in hopes of potentially achieving in the future a significant climate impact together. Our partners at the Autonomous University of the State of Mexico and U.C. Davis helped us develop a FAQs page, and other resources to guide those efforts. Our next step is to expand the program in our own supply chain as widely as possible, while continuing to study the potential of lemongrass, long-term impact (if any) on cows, and other potential variations to the Cows’ Menu initiative.

We know that it will take time and collaboration to make the Cows’ Menu program a mainstream reality and we are encouraged by the initial feedback.

Partnering to expand the Cows’ Menu in our supply chain:

We are currently embarking on partnerships with supply partners – in Ireland, Austria, Mexico and Brazil – to expand the Cows’ Menu initiative into their operations and further test the commercial viability of a lemongrass supplement. With these next pilots, we will test the formula over a longer period of time and on bigger cattle herds. We will build data in important areas such as animal performance, emissions over time, and economic impacts for farmers, while keeping a close eye on animal welfare.

Marcher Fleischwerke in Austria, who ran the first of these following studies, found that feeding 100 grams of lemongrass to cattle, reduces the CH4 emissions in the breath by an average of 14.6% in Austrian ranching conditions. The full report can be found here.

locations map
Kepak (Ireland)

We are partnering with Kepak in Ireland to test the commercial implications of the Cows Menu program in the supply chain. Feeding the lemongrass over a longer period will provide us with important learnings for farmers and ranchers on emissions, as well as animal weight gain and health.

Marcher Fleischwerke (Austria)

Our collaboration with Marcher Fleischwerke and the University of Vienna aims to validate the findings from our Mexico research. Focused on methane emissions, the pilot involves replicating the Mexico research – measuring emissions using respiration chambers in a lab – plus a secondary test measuring on a local form. The final report found that in Austrian ranching conditions, feeding 100 grams of lemongrass reduced the CH4 emissions in the breath by an average of 14.6%.

GUSI (Mexico)

We are collaborating with GUSI in Mexico to validate the findings from the research conducted at the Autonomous University of the State of Mexico and test the commercial implications of the Cows Menu program in the supply chain.

JBS (Brazil)

We are partnering with JBS in Brazil only to test the commercial implications of the Cows Menu program in the supply chain. Feeding the lemongrass over a longer period will provide us with important learnings for farmers and ranchers on emissions, as well as animal weight gain and health.

Expanding the use of the Cows Menu formula will require a whole lot more lemongrass, so we are supporting our supply chain partners by identifying lemongrass suppliers who can grow with us. Our research suggests that Cymbopogon citratus is better suited to optimize the reduction in methane and so we have developed a specification of this type of lemongrass with the suppliers that we are in discussions with. We recognize that increased demand for other crops has brought sustainability challenges, so sustainable production is a key part of the conversation with lemongrass suppliers.

What does
this mean
for my burger?



Adding lemongrass to the cows’ diet has shown no impact on the taste or texture of the meat in our Whopper. We continue to deliver on our delicious flame grilled flavor that our guests have come to know and love.

The Reduced Methane Emissions Beef – coming from cattle fed the lemongrass supplemented diet - will be available in select restaurants in July 2020. This beef patty will be used for the Whopper and all large burgers currently served at select restaurants in Miami, New York, Austin, Los Angeles and Portland. These burgers will be labeled “REDUCED METHANE EMISSIONS BEEF”, during the promotion period. Beyond launch, we will continue to partner with educational institutions and industry scientists to conduct additional research on this topic. We are also working with suppliers across the globe to expand the program in our supply chain over the coming months. We intend to report out the findings of these pilot partnerships periodically, and will continue to keep stakeholders updated on progress through our parent company, Restaurant Brands International.

Wait, what about the Impossible™ and Rebel Whoppers?
We are providing guests with more options on climate friendly food in our restaurants. As delicious as the classics, both the Impossible™ and Rebel Whopper patties are made from plant-based ingredients. These options are widely available, with our Impossible™ Whopper in US restaurants, and our Rebel Whopper served in the UK, Brazil, Australia and throughout continental Europe. Though Burger King has not calculated the footprint of our plant-based burgers, our partners at Impossible™ Foods have calculated that compared to a beef burger, their burgers use 96% less land and generate 89% fewer GHG emissions.

The plant-based Whopper patties and the new Cows Menu-fed beef at Burger King are two great ways you can continue to enjoy your favorite burger while knowing Burger King is working hard to balance that great taste with potentially lower future climate impacts.


"We're in the business of selling burgers, so we wanted to make a positive impact on climate change without impacting the flame-grill flavor that our guests already know and love."


What's next?


The initial achievements of the Cows Menu program is progress we're proud of. With our partners we have targeted a significant emission source and found that lemongrass could potentially reduce the climate impact of beef production in the future. However, we recognize that nearly all solutions have challenges.

Cows Menu will not solve the climate change problem in the short-term, but it is a scalable solution where we hope to see the impacts in our lifetime. We are challenging the industry to improve, and Cows Menu is proving that significant improvements are possible by bringing together leading scientific expertise and partnering and sharing lessons along the value chain.

Burger King will continue to pursue innovation and collaboration as we target the 2030 sustainable development agenda and global climate goals. Through the Cows Menu program, we invite the feedback, research and participation of the broader beef industry so that together we can meaningfully make a positive climate contribution in the future.