Collection of 'watery' fish waste
Hi!
We usually collect fish waste from the fish market down the road every weekend. It comes with quite some water and blood as a result from the cleaning and rinsing. The liquid amounts to about a liter over maybe 6-7kg of solids...Shall I leave the liquid and mix it with sugar together with the solids? Or better to strain the water and use only solids from the fish waste?
Thanks!
Top answer
The blood and water can turn the batch no good. I have found in my experience it is best to work with just the solids. The blood can be fermented separately for more immediate use.
From the KNF library
From the KNF library
Drafted by Claude from Office Hours and the books
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Sep 2026
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5 sources
The library covers the sugar side of the solids.
- Mix fish waste and brown sugar at a 1:1 weight ratio. For your 6-7 kg of solids, that is about 6-7 kg of sugar. (Cho, Recipe, p. 49)
- Another source gives a wider range: 30% to equal parts sugar by weight. The two sources differ. (KNF Demystified, p. 39)
- Use fresh waste only. Do not use salted fish. (Cho, Recipe, p. 48)
- Check after 3 days. If it smells, add more sugar. (Cho's Solutions, p. 13)
Within 3 to 4 days, osmotic pressure from the sugar starts to liquefy the waste. (Cho, Recipe, p. 50)
The library says nothing about the market's water and blood, or about fermenting blood separately.
Sources
- p. 48 Cho, Recipe · “Use fresh waste only; do not use salted fishes”
- p. 50 Cho, Recipe · “In 3 to 4 days, the fish waste starts becoming liquidized through the osmotic pressure generated by the brown sugar”
- p. 39 KNF Demystified · “Combine between 30% ~ equal parts by weight of brown sugar and stir with a stick”
- p. 13 Cho's Solutions · “Check next 3 days, if smell, add more sugar”
- p. 49 Cho, Recipe · “Put fish waste (head, bone, intestines) and brown sugar in the clay jar with a 1:1 weight ratio.”
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