A fermentation of a milk source to manufacture a fermented milk product with malty-chocolate-honey-butter-cream flavor and aroma. Fermentation is achieved by addition of adding a Lactococcus lactis subsp. lactis diacetylactis (CNCM No. I-4404) or a Lactococcus lactis subsp. lactis diacetylactis (CNCM No. I-4405) A further bacteria Lactococcus lactis subsp. lactis biovar is also added to the milk source. The milk source comprises amino acids and citrate prior to fermentation.