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KALARVO R1 — Preliminary report
The first round of the KALARVO BSF larvae trials is done — 39 recipes, three Kainuu fish side-streams, one container, one round. Not a final answer, but four things stood out from the preliminary report worth sharing now.
01 · Project
A public R&D project
KALARVO is a public R&D project commissioned by Kajaanin ammattikorkeakoulu (KAMK), executed by Manna Insect and Jepro Ab. R1 is the screening round — wide net, looking for surprises. We found some.
02 · Side-streams
Fish side-streams are not one thing
1) Fish side-streams are not one thing.
Three streams from Finnish processors — four substrates once you split rainbow trout offal into its oil-extracted and acidified forms. All sit at 75–80 % moisture, all need a structural carrier, and none behave the same once mixed. Mixed whole lake fish carries its own bones and skin. Fillet waste is more uniform muscle. Offal has free oil and protein. Each one wants a different mix.
03 · Conditions
Stable high-temperature, high-humidity conditions
2) Stable high-temperature, high-humidity conditions are the precondition for everything else.
R1 ran at ~32 °C and ~72 % RH, held inside a tight band for 12 days while outside swung 0–15 °C and 25–95 %. High temperature accelerates larval metabolism. High humidity keeps the substrate workable for the full cycle. Stability is what makes the recipes comparable batch-to-batch. The MIND IoT system on Jepro's container did this work in the background — without it, the rest of these observations would be noise.
04 · Duration
Recipe, not the container
3) Recipe — not the container — drove rearing duration.
Same environment. Same 10,000 five-day-old larvae per tray. Same 8 kg load. Yet some recipes were already past peak on day 7 with substrate drying out, others were still actively feeding on day 11. Day 8 looks like a practical sweet spot for most of the 39 — but only most.
05 · Outcome
Same fish, different mix
4) Same fish, different mix → wildly different outcome.
Clearest case: acidified trout offal at 30 % fish, two recipes, same inclusion. One paired with potato — biggest individual larvae of the trial, around 183 mg. The other paired with wheat bran only — bottom of the ranking. The carrier choice mattered more than the fish percentage. We saw versions of this across the other fish streams too.
06 · Caveat
Screening scale, nothing concluded
Caveat we are taking seriously: this is R1, one container, screening scale. Nothing concluded yet. More rounds run in May and June with the R1 learnings applied, and the final report with full laboratory analysis lands in August.
07 · Report
The R1 preliminary report
The 5-page R1 preliminary report is in the document below if you want the numbers and the failure modes. What we'd really like is your operator instinct on what should be tested next — drop a comment.
Keep exploring
Related topics and pages
- Articles library — the written notes this preliminary report joins
- KALARVO R1 update and public project introduction — the project introduction that set up this screening round
- KALARVO Recipe Test Round 1 Teaser — the round 1 teaser from the same KALARVO recipe work
Read next
- KALARVO R1 update and public project introduction — the project introduction that set up this screening round
- KALARVO Recipe Test Round 1 Teaser — the earlier round 1 field note from the same KALARVO work
- BSF Metrics #4 — Temperature: Substrate Is the Target, Air Is the Medium — the temperature target behind the stable climate band this round relied on
- BSF Metrics #6 — Substrate Quality and FCR: Real Biowaste Converts Better Than You Think — the substrate-quality and FCR metric from the same series
Next step
Follow the KALARVO results
Manna can help turn a fish side-stream question into a defined trial with comparable recipes and controlled conditions.