Waste stream assessment report: Review of feedstock streams for black soldier fly larvae production by multiplier companies in Kenya and Tanzania

This report presents a review of the feedstock streams used by two black soldier fly larvae (BSFL) multiplier companies in Kenya and Tanzania, to assess the sustainable availability of suitable substrates for production and potential or scale-up of BSFL production. Data were collected using a waste stream assessment questionnaire administered to key operational staff in the two companies. The assessment examined the types, sources, volumes, seasonality, and characteristics of feedstock streams used in 2024 and 2025. Secondary data from company databases were also analyzed to understand seasonal availability and variability across feedstock types.
The findings show that the Kenyan multiplier company operates two production sites, in Limuru and Thika, with daily waste intake capacities of 30 tons and 100 tons, respectively. Its main feedstocks are mixed fruit and avocado waste from fruit-processing factories, supplemented by smaller quantities of blood and feathers from slaughterhouses, as well as liquid whey and expired cheese from dairy processors. Although mixed fruit and avocado waste are seasonal, the company has used storage solutions and has not experienced production shortages since 2020. The primary feedstocks are not purchased; costs are mainly related to transport and range from USD 0.004 to USD 0.012 per kilogram for avocado waste, and about USD 0.0134 per kilogram for mixed fruit waste, based on an exchange rate of KES 130 to USD 1 in September 2025. More than 3,000 tons of avocado waste are available monthly for both sites, and an estimated 1,120 tons of waste from seven partners could be sourced daily for the Thika site alone. This supply exceeds the current daily intake and production capacity of the Thika site. Therefore, despite current bioconversion rates of below 9% for avocado waste, feedstock availability is sufficient to support increased production at the Thika site.
In Tanzania, the multiplier company operates production sites at Salasala in Dar es Salaam and Muriet in Arusha. The Salasala site has a daily waste intake capacity of about 30 tons and relies mainly on brewers’ spent grain (BSG), brewers’ spent yeast (BSY), and mixed market waste. The use of these organic waste streams demonstrates a practical circular bioeconomy approach to BSFL production by converting low-value organic residues into animal feed ingredients and organic fertilizer. This contributes to waste valorisation, reduces environmental pollution, and creates alternative income opportunities for actors along the BSFL value chain.
However, feedstock availability remains a major constraint for the Tanzanian company. Key challenges include seasonal fluctuations in feedstock supply, competition for BSG, and inefficiencies in municipal waste collection and management. Despite these limitations, the company achieves an average bioconversion rate of about 8%, indicating effective use of the organic resources currently available.
Sustaining and expanding BSFL production will require stronger partnerships with waste management institutions, diversification into alternative organic waste sources, and improved coordination with suppliers to secure consistent and affordable feedstock throughout the year. Overall, the experience of the two multiplier companies shows that BSFL production can be integrated into urban organic waste management systems, generating both environmental and economic benefits while supporting the development of alternative livestock feed ingredients.