Repurposing by-products to alternative applications has become a vital part of food research. Barley rootlets (BRs) are side-stream malting and brewing industries. This study focuses on processing BRs into ingredients, using fermentation with five lactic acid bacteria (LAB) as valorisation technique. The strains used were Lactiplantibacillus plantarum FST 1.7, Lactobacillus amylovorus FST2.11, ...