Nutrient upcycling: Spent brewery grain to insect protein and more

The document details the use of Black Soldier Fly (BSF) larvae to convert low-grade organic waste into high-value protein and oil for animal feed, pet food, and pharmaceuticals. It focuses on Maltento, a Cape Town company that processes organic by-products like spent brewery grain and fruit/vegetable pulp. The study argues that this circular economy approach reduces landfill reliance, lowers greenhouse gas emissions, and decreases dependency on volatile global imports of soy and fishmeal. In 2021, Maltento processed approximately 6,000 tonnes of organics, creating jobs and providing a more stable price for protein derivatives.

• Black Soldier Fly (BSF) larvae are highly efficient at converting organic waste into protein, with a feed conversion ratio capable of turning 10 tonnes of feed into 1 tonne of protein.
• The global food system is a significant source of emissions, contributing between 21% and 37% of global greenhouse gas (GHG) emissions, while methane from organic waste in landfills accounted for 10–11% of Cape Town’s emissions.
• Maltento's BSF facility in Epping has a current processing capacity of approximately 20 tonnes of co-product inputs per day, with plans to scale to 50 tonnes in the medium term and hundreds of tonnes in the long term.
• In 2021, Maltento processed approximately 6,000 tonnes of organics, of which 3,000 tonnes were likely destined for landfill, effectively freeing up 2,400 cubic meters of landfill airspace.
• Maltento generates significant economic value by extracting approximately R14,300 from every tonne of organic inputs, adding over R85.7 million in product value back into the economy in 2021.
• The production of BSF protein reduces environmental pressure on wild fish and forests; one tonne of BSF protein can replace five tonnes of wild fish, and it displaces soy protein, which is a major driver of deforestation.
• Maltento's operations in 2021 may have saved between 6,200 and 7,100 tonnes of GHG emissions compared to landfill disposal, although these figures are unverified.
• The company produces a variety of high-value derivatives from BSF larvae, including protein meal, oil rich in lauric acid, dried grubs, and frass, which serves as a non-fossil fuel based organic fertiliser.

APA

GreenCape (n.d.). Nutrient upcycling: Spent brewery grain to insect protein and more. https://greencape.co.za/wp-content/uploads/2022/11/Spent-Brewery-Grain-to-Insect-Protein.pdf

Chicago

GreenCape. Nutrient upcycling: Spent brewery grain to insect protein and more. n.d. https://greencape.co.za/wp-content/uploads/2022/11/Spent-Brewery-Grain-to-Insect-Protein.pdf.

Wikipedia

{{cite report |author=GreenCape |title=Nutrient upcycling: Spent brewery grain to insect protein and more |url=https://greencape.co.za/wp-content/uploads/2022/11/Spent-Brewery-Grain-to-Insect-Protein.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{greencapendnutrient, author = {{GreenCape}}, title = {{Nutrient upcycling: Spent brewery grain to insect protein and more}}, institution = {GreenCape}, url = {https://greencape.co.za/wp-content/uploads/2022/11/Spent-Brewery-Grain-to-Insect-Protein.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }