Learn · Articles
BSF Metrics #7 — Dried Product Yield
BSF Metrics That Actually Matter #7 — Dried Product Yield. The last post in the series, and the number every business plan should start with.
01 · The anchor
Why the number matters
Almost none of them do.
Most plans lead with the wrong anchor — waste throughput ("5 tons per day"), gross larvae ("765 kg live daily"), or the headline ("BSF reduces organic waste by 50–85%"). None of those tell you whether the business pays.
The number that matters is dried product yield — kg of sellable dried larvae per ton of waste in. It is much smaller than people expect.
02 · The cascade
The cascade
Start with 100 kg of biowaste.
At a realistic 17% bioconversion ratio, that produces 17 kg of gross live larvae.
Subtract ~10% mortality and ~5% retained for breeding. You have 14.5 kg of sellable live larvae.
BSF larvae are ~70% water. Drying ratio ~2.9:1. After drying to a shelf-stable 12% moisture, those 14.5 kg become 5 kg of dried product.
5 kg from 100 kg in. ~5% effective yield.
The gap between "50–85% waste reduction" and 5% sellable product is where most BSF business plans collapse. Using live-larvae weight or the waste-reduction headline as the revenue base overstates the case by 3–10×.
03 · Facility sizing
Why this decides facility sizing
At 5% effective yield, 1 ton of dried product needs ~20 tons of biowaste. Every day. Weekends, holidays, rainy season when collection gets hard.
If supply cannot sustain that volume year-round, the facility runs underutilised — and fixed costs (rent, depreciation, minimum staffing, the $100/tn OPEX line from last week) do not scale down with throughput. Tight margin becomes loss fast.
The most common failure mode in BSF business planning: a facility sized for waste that exists on paper but not reliably in practice.
04 · Work backwards
Work backwards, before you build
What can you sell dried BSFL for, in your local market, this month? Not the premium price you hope for. For soy-parity markets, within ~15% of local soy meal price.
How many kg per month do you need at that price to cover OPEX, loan payments, and the salary you take home?
Divide that monthly kg target by 0.05 (the 5% yield). That is your monthly waste volume. Divide by 30 for daily throughput. Can you source it? Reliably? Every day?
If yes, proceed to detailed planning. If not, scale down or find more sources. Figure this out with a spreadsheet and phone calls — not a built facility.
05 · Closing the series
Closing the series
BCR sets gross output. Cycle length sets batches per month. Moisture and temperature decide whether you hit your target BCR. Substrate quality sets the ceiling. Density and survival decide what fraction of gross larvae becomes sellable. Dried yield is what all six cascade into.
Improve one and the 5% improves. Let one slip and it drops to 3% or 2% — and the facility moves from viable to marginal.
Track all seven. But start the business plan with the last one.
What is the effective dried yield in your business plan? Not waste reduction. Not live weight. The sellable dried kg per ton of waste in.
Keep exploring
Related topics and pages
- BSF Metrics #6 — Substrate Quality and FCR: Real Biowaste Converts Better Than You Think — the previous metric in the same seven-post series
- BSF metrics series — the teaser that introduced the whole metrics series
- Articles library — the written library this final metric post joins
Read next
- BSF Metrics #6 — Substrate Quality and FCR: Real Biowaste Converts Better Than You Think — the previous metric in the same seven-post series
- BSF metrics series — the teaser that introduced the whole metrics series
- The $100/tn OPEX Target for Live Larvae — the operating-cost line this post refers back to
- BSF Business Case Service — how the dried-yield number lands in a full BSF business case
Next step
Check dried yield on your own material
Manna can help test what a specific biowaste and process actually yield as sellable dried product, and what that means for facility sizing.