What's the climate impact of malted barley and hops?
August 4, 2023
Beer production requires four main ingredients of water, grain, hops and yeast. The carbon footprints of each of these ingredients plays a crucial role in influencing the overall climate impact of the final product of the beer. Focusing in on two of these main ingredients, malt and hops, we will find out what are the biggest sources of emissions in their farming processes.
By exploring where these emissions are coming from we can gain a better understanding of the carbon footprints of malt and hops and discover the best ways to work towards reducing these.
What is malt?
Malt is grain that has been force germinated through being soaked in ambient water before being heated to dry the grains and allow the flavour to develop. Many types of grains can undergo the malting process, such as oats, wheat and, most commonly, barley. After barley has been processed into malted barley (malt) it can then be used to make beer and whisky.
What is the climate impact malt?
87% of the carbon footprint of malt comes from the farming of barley, the processing of the barley into malt makes up another 11% of the footprint and the remaining 2% is from transportation emissions. Source.
🚜 Agriculture - Barley
Now, let’s take a step back and see how the farming of barley makes up 87% of the carbon footprint of malt.
Barley has a carbon footprint of 0.59 kg CO₂e/kg. This comes entirely from the farm level and in two forms; carbon dioxide and nitrous oxide from a variety of sources.
Carbon dioxide sources:
34% Energy - used to produce fertilisers and pesticides (11%), power farm machinery (13%), dry the barley (9%) and run irrigation systems (1%).
33% Farming on drained wetlands - wetlands are extremely efficient blue carbon habitats meaning they have the ability to store large amounts of carbon, however, when this land is drained to make it suitable for farming the stored carbon is released.
8% Limestone and urea - these are used to maintain the correct soil conditions for crop growth, both of which contain CO₂ which is released when used.
Nitrous oxide sources:
21% Bacteria - bacteria in the soil digest fertilisers and crop residues which in turn releases N₂O.
4% Farming on drained wetlands.
🏭 Processing - barley to malt
Going from barley to malt increases the footprint from 0.59 CO₂e/kg to 0.77 CO₂e/kg, almost all of this increase of which comes from the processing. Let’s have a quick look at the basic steps for how barley is processed into malt and where the additional carbon emissions are coming from. The majority of the footprint from the malting processing are due to the emissions caused by the energy required for heating.
📉 How can the carbon footprint of malt be decreased?
Although the average carbon footprint of malt in the UK is 0.77 kg CO₂e/kg, this can massively vary depending on where the malt is sourced from. It is essential to think carefully about who you are getting your malt from and to work with suppliers who, not only assess their environmental impacts, but are also working hard to reduce them. By focusing on the areas that contribute the most to the carbon footprint of malt, as seen above, suppliers can effectively work to minimise these climate impacts.
For example, Muntons are tackling some of their malt emissions by investing in onsite renewable energy, helping to decrease emissions caused by the energy needed for the processing of malt. Positive changes like these have resulted in Muntons achieving a carbon footprint nearly 50% lower than the national average!
Other companies like Simpsons Malt have worked to reduce the transportation portion of malt's carbon footprint by switching to HVO fuel in their trucks. This has led Simpsons to have successfully reduced their transportation emissions by more than 90%.
Now let’s move on and take a look at one of the other key ingredients of beer - hops.
What are hops?
Hops play a vital role in the beer making process contributing to the bitterness, flavour and aroma of beer, as well as acting as a natural preservative. Each variety gives a beer a different taste profile, from fruity and hazy hops like Simcoe to a more bitter profile from a Columbus. We know they give beer their taste, but what’s their climate impact?
What is the climate impact of hops?
Much like with barley, the footprint of hops comes in two forms of greenhouse gas emissions, carbon dioxide and nitrous oxide. However, hops have a footprint almost 7x higher than barley per kg, so where are these extra emissions coming from? Let’s have a look at the breakdown.
The average carbon footprint of hops from the UK is 4.0 kg CO₂e/kg
This can be broken down into the following sources.
Carbon dioxide sources:
54% Energy - used to dry the hops (32%), produce fertilisers and pesticides (12%) and power farm machinery (10%).
22% Farming on drained wetlands.
9% Limestone and urea.
Nitrous oxide sources:
11% Bacteriain soil.
3% Farming on drained wetlands.
1% Energy - used to produce fertilisers.
A much greater portion of carbon dioxide emissions in hops come from the drying process, contributing 1.3 kg CO₂e/kg to the overall footprint. This means that from drying emissions alone, hops has a footprint almost double that of barley.
👇🏻 How can the carbon footprint of hops be decreased?
As a brewery, the key to reducing the environmental impact of hops is working with suppliers, much as we have already seen with malt. Suppliers that measure their emissions and are working to reduce the carbon footprint of their hops through improvements in the production process are essential. At the farm level, there are many ways in which this can be done as illustrated by the breakdown of the carbon footprint of hops. For example, using renewable energy sources for the drying of hops, which makes up about a third of the total emissions from hops production, could have significant impacts.
The importance of making these positive changes to the hops production process at a farm level is highlighted by the location where the hops are sourced from being evidently less important to emissions than how the hops are being produced. Surprisingly, buying local when it comes to hops doesn't always lead to the lowest emissions, for example, hops sourced from the USA can be seen to have 5% lower emissions than hops from the UK. These comparison tables show that even after accounting for increased transportation emissions, the total emissions of hops from the USA are still lower. This indicates the relatively lower importance of transport compared to raw material emissions which are higher in the UK and shows that this is an area with great potential for emissions reductions.
Despite hops having a significantly higher carbon footprint per kg than malt, it is important to note that malt still makes a greater contribution to the overall footprint of beer. This is due to much larger quantities of malt being required to make beer than hops.
Having access to accurate data on the carbon footprints of your raw materials is not only interesting but can help you find the best ways to work towards reducing emissions.
Supporting suppliers striving for sustainable practices and pushing them to continue reducing their impacts is keys ultimately how your raw materials are produced and processed is at the core of reducing your own supply chain emissions.
Understanding your climate impact isn't easy, but that's where Zevero comes in. We can help pull together all of your emissions data, help you make sense of it and support you in working to reduce your climate impact.