Described are Pichia kluyveri yeast strains with advantageous properties useful in cacao fermentation processes, and related methods and products, including fermented cocoa beans having a ratio of isobutyl acetate/isobutanol higher than 1 and/or a ratio of isoamyl acetate/isoamyl alcohol higher than 0.005, and cocoa-based products prepared therefrom, as well as methods for the fermentation of cocoa beans comprising using at least one Pichia kluyveri yeast strain, fermented cocoa beans obtainable thereby, and cocoa-based products prepared therefrom and obtainable thereby.