Off-Flavour Control

Off-flavour control is the most advanced use of active microbiome management, a step beyond seeding a biofilter or holding nitrification steady. Where nitrification is a single pathway, breaking down geosmin and MIB draws on different modes of action and biological function within the consortium, working alongside good biofilter design and housekeeping to reduce off-flavour compounds at source.

Geosmin and MIB are produced by bacteria that build up in recirculated water and taint the flesh. People detect geosmin at very low levels, so even small amounts matter. The usual fix is depuration, holding fish in clean water for days or weeks while growth stalls. Active microbiome management addresses the biological side directly instead, breaking these compounds down and crowding out the organisms that make them, so fish keep feeding.

At Kuterra's land-based salmon farm in British Columbia, applied with the full method, RAS-Right grown in a Bioreactor Grow-Tank and dosed for off-flavour control, geosmin was brought below the 5 ng/L limit for acceptable flavour after 115 days and held there for months, with makeup water back below design levels.

“We're now getting Geosmin levels consistently below our maximum limit, coupled with only requiring design rates of makeup water, which is unprecedented in our site.”
— John Burton, Kuterra

Off-flavour is a whole-system matter, so we look at your biofilter, housekeeping and dosing together, and are straight about what active microbiome management can and cannot do for your site.