FERMAID O is an organic yeast nutrient that contains 100% natural yeast derived components rich in organic nitrogen. FERMAID O supplies well balanced nutrients for yeast including highly available amino acids and peptides, taken up more slowly than DAP into the yeast cell. Once inside the yeast cell the alpha amino acids are integrated directly into proteins, degraded to ammonium or used to produce aromatic esters. FERMAID O increases the expression of some aromatic fruity esters when compared to inorganic nitrogen alone. This has been well supported by many trials. FERMAID O is highly desirable for food industry applications where it increases the expression of some aromatic fruity esters when compared to inorganic nitrogen alone. FERMAID O increases the expression of some aromatic fruity esters when compared to inorganic nitrogen alone.