The circular economy model created in Lahti by Hartwall, Lahti Energy and the local Yli-Mäkelä estate is unique even on a global scale. Ingredients circulate from barley fields through brewing tanks and biogas reactors back into the field – all within the space of just a few kilometres. Thanks to the model, Hartwall has achieved its net zero emissions target ahead of time.
The white domes in front of Hartwall’s beverage factory in Lahti resemble giant igloos. They stand out from their surroundings like the set of a science fiction movie. The domes are biogas reactors, and below is the factory’s own biogas plant.
”And if you look that way, there’s the beer brewery”, says Mika Mäkelä, Development Manager at Hartwall, pointing to a few tens of metres away.
”And over there, a truck from Viking Malt next door is driving in”, he continues.
The truck brings in the malts needed for brewing beer. Beer wort is brewed from the malts through a process of mashing and lautering. A by-product of the process is the spent grain mash that fails to break down into the wort.
”Spent grain is pumped in a pipeline there”, Mäkelä explains.
The pipeline transfers the mash into the biogas reactors under the domes. Here, in an oxygen-free space, the mash begins a biological decomposition process. Microbes start breaking down the mash, and within a few months, the carbon contained in the mash turns into methane or biogas.
Next, the biogas is transferred to Lahti Energy’s gas boiler and used to produce heat energy for Hartwall’s own use. Thanks to the biogas, Hartwall’s production process is now entirely carbon neutral.
Mäkelä explains the process and points to the buildings around the factory grounds. Finally, he stops to point to a low building behind the reactors, which houses tanks used to collect rejected materials from the biogas process, to be recycled as fertiliser for the fields of local contract farmers to grow new barley crops.
Eight kilometres from Hartwall’s factory in Renkomäki, Lahti, Heikki Mäkelä, owner of Yli-Mäkelä estate, surveys his fields and assesses the ripeness of malt barley crops.
”We can get started with the harvest in about a week or so, he concludes confidently.”
At Yli-Mäkelä estate, the traditions of growing crops go back three hundred years. Heikki Mäkelä, a farmer in the tenth generation, works on the estate together with his son Antti Mäkelä. In time, he will become the eleventh owner of the estate.
The fields in Yli-Mäkelä are used for growing rye, wheat, oil plants and malt barley – precisely the barley used as raw ingredients for Hartwall’s beers. Barley from the farm makes a full circle as it travels from fields through the malting plant, beverage factory and biogas reactor back to the field to fertilise the next barley crops.
The transport distances between the malting plant, the factory and the reactor’s reject tank are only a few kilometres, which saves a significant amount of transportation costs and reduces carbon emissions.
Decades ago, Yli-Mäkelä estate used manure from its own cattle and pigs as fertiliser, but this ended when the farm gave up livestock production. For many years, the estate’s 680 hectares of crop fields depended on mineral fertilisers, which, while effective, are not the best solution for soil health.
Heikki Mäkelä explored options for organic fertilisers from various source and eventually, a solution was found through Hartwall’s cooperation.
”Studies have shown that organic fertiliser is the best option for soil health and microbes. It increases microbial activity and humus content, and has been proven to improve the quality and quantity of crops. This way, the soil is able to retain moisture better and withstand extreme weather conditions”, explains Antti Mäkelä, the estate’s young agrologist.
Neighbouring farms have also shown interest in the solution, and the Mäkelä family has helped spread the word about organic fertiliser.
”Just yesterday, we were contacted about the topic”, Antti Mäkelä says.
Heikki Mäkelä lists neighbouring farms that are already receiving biogas reject material, but the Yli-Mäkelä estate is a pioneer in circular economy partnerships after investing in four reject tanks used as intermediate storage for the fertiliser. The odourless reject water is also suitable for use on fields that are located near urban areas.
Another advantage is the fast solubility of the reject material. The reject dissolves at the same speed as a chemical fertiliser, which means that the nutrients are immediately available for the plants. The nitrogen and phosphorus contained in the mash area are also in a form that is easier for plants to use than fertilisers of animal origin.
Hartwall’s flagship beverage factory in Lahti produces iconic Finnish drinks such as Jaffa, Pommac and Novelle, as well as several beers. Hartwall’s current production facility in Lahti was launched in 2003. One reason for the location is the clean groundwater filtered in the ridges of the nearby Salpausselkä, the most valuable raw ingredient in the beverage factory.
The concept of a circular economy model using spent grain mash from the brewing process was born when the factory considered ways to reduce the use of natural gas and discover more sustainable forms of energy production.
Previously, the by-products of beer brewing had to be transported by trucks from the factory. To reduce emissions, the brewery began looking for ways to use the mash directly on the site. When a replacement for natural gas was needed, the non-fossil fuel biogas proved to be a natural alternative.
While biogas production is not uncommon, the concept applied in Lahti is unique for its comprehensiveness spent grain mash is used as a raw material for biogas to be used in the factory’s processes. The rejected material from the biogas reactor is given a new purpose and used as fertiliser in local fields.
The success of a circular economy model requires favourable conditions, and in the case of Hartwall, everything went right. The Lahti region is a traditional barley farming area and home to many malthouses. In addition, the factory had enough room for an on-site biogas plant and the opportunity to use old boilers for energy production.
”In order to make financial sense, the model requires the right conditions and distances”, Mika Mäkelä points out.
”Originally, our goal of achieving carbon neutrality and zero carbon emissions from fossil fuels was set for 2025. Now, thanks to the biogas plant, we’ve hit the target a few years early. We now operate with net zero carbon emissions”, Mäkelä says.
Hartwall has managed to reduce its emissions not only by transitioning from fossil fuel-based natural gas to biogas, but also by other means, such as using recycled materials in packaging and converting its fleet to electric trucks.
All electricity used at Hartwall has been entirely green and renewably sourced for years.
At the Lahti brewery, water, heat and steam are reused as many times as possible. Heat generated in production processes is recovered and used for heating facilities. Hartwall has access to energy from an old landfill nearby.
Gases that would otherwise end up in the atmosphere are used to generate up to 5 GWh of energy annually.
As much as 99.8% of waste is recycled or reused. Even bubbles are recycled: Half of the carbon dioxide needed in carbonated soft drinks comes from the beer brewing process. Before it ends up in bottles, the ice-cold carbon dioxide has one last task. It is used to cool the brewery’s equipment and facilities.