This dataset describes the outcome of fermentations of S.latissima with lacic acid bacteria under different conditions. It is a full factorial design matrix with the following factors and levels: Inoculant (Column B): SiloSolve, PigStabilizer, TopSil Max Additional mannitol fermenting organisms L.rhamnosus + L.paracasei: yes/no (Column C) Addition of oxygen scavengers VegaSafePro01+VegaSafePro03: Yes/No (Column D) Harvest season: Spring/Fall (Column E) Washing and blanching: yes/no (Column F) Storage time of fermented seaweed: 2 months/4 months (Column G) The following analytical results are described: pH (Column H) Bloating (arbitrary scale, Column I) Mass fractions of metabolites in mg/g freeze-dried, fermented seaweed lactate (Column J) alanine (Column K) butyrate (Column L) acetate (Column M) formate (Column N) betaine (Column O) mannitol (Column P) total protein in mg/g freeze-dried, fermented seaweed (Column Q)