Julia Brenner and Björk Brynjarsdóttir rest in a green oasis within an eroded landscape in Rangárvallasýsla County, revived through their prototype system in 2022. (Photo courtesy of Karim Iliya)
In rural Iceland, managing waste and maintaining soil health are closely intertwined challenges. Globally, improper organic waste disposal contributes to about 6 percent of greenhouse gas emissions, missing opportunities to restore vital soil nutrients—a significant concern for a country with significant soil erosion. High costs and logistical difficulties, particularly due to Iceland’s unpredictable weather, emphasize the need for local solutions addressing waste management and soil restoration.
Melta, an Icelandic start-up cofounded by Julia Brenner and Björk Brynjarsdóttir in 2020, tackles waste management in rural farming communities through bokashi fermentation, a process similar to pickling. This method uses microorganisms thriving in oxygen-free environments to break down organic waste in sealed containers, reducing odors and preventing rot. The process transforms food scraps into fertilizer that improves soil quality and crop growth and supports sustainable farming practices.
Instead of focusing on individual households, Melta’s system is designed for entire communities. Households first collect organic waste in airtight buckets treated with a microbial spray, after which Melta collects and ferments the waste for six to eight weeks. “The resulting fertilizer retains up to 90 percent of the original waste material, compared to traditional composting methods, which retain only 40 to 60 percent,” says Brynjarsdóttir.
Melta partners with small municipalities facing high transportation costs to send waste to Reykjavík. Their system processes waste locally, aiming to cut transportation, which can account for up to 90 percent of rural waste-management costs. “Rural municipalities spend 90 to 255 percent more on waste management than urban centers,” Brynjarsdóttir explains. Two pilot projects conducted between 2021 and early 2023 in Ásahreppur, Rangárþing Ytra, and Rangárþing Eystra counties demonstrated a 70 percent reduction in waste transport.
The 2021 pilot study demonstrated the feasibility of fermenting large amounts of organic waste, although they encountered contamination from nonorganic materials. By 2022, they had reduced nonorganic materials like plastic in the waste to less than 0.05 percent. They aim to reduce waste collection frequency to every six weeks, cutting transportation by 71 percent and saving 32 tons of CO2 annually.
Melta’s fermentation process provides a practical solution for rural areas without composting facilities, allowing them to meet regulatory requirements by managing organic waste locally without investing in costly, large-scale composting infrastructure. Their system claims to reduce composting costs by up to 70 percent, making it more accessible to farmers. With fertilizer prices increasing nearly 30 percent due to the war in Ukraine, their system is positioned as a cost-effective solution for waste management and soil restoration.
Despite these advances, Melta faces regulatory hurdles in gaining approval for their fermented waste to be sold commercially, due to the complexities of meeting regulatory standards for this new product. Collaborations with Agricultural University of Iceland and the Soil Conservation Service of Iceland are ongoing, but scaling operations will require more infrastructure and investment than what has been possible on grants and self-funding.
Looking ahead, Melta plans to establish microbreweries—small, localized facilities for waste processing. Currently, the founders manually process organic waste with pitchforks and shovels, but these microbreweries would automate and streamline the fermentation process in rural communities, turning organic waste into fertilizer on-site. This would significantly reduce the need for long-distance transportation, improve operational efficiency, and expand their model to more rural areas, allowing communities to manage waste locally and restore soil health. Their long-term goal is to decentralize fertilizer production and reduce emissions through local processing. If fully scaled, they estimate their system could restore 2,100 hectares (nearly 5,200 acres) of land annually in Iceland and capture up to 2.78 million tons of CO2 by 2050.
While their primary focus is Iceland, Melta is open to exploring opportunities in other regions and continuing to validate the environmental benefits of their system, including carbon sequestration and soil restoration. By setting a precedent in Iceland, they hope to inspire rural communities across Europe and beyond to adopt similar waste processing systems.
Read more stories by Robyn Huang.