Fermaid-O Yeast Nutrient 50g

Premium Organic Yeast Nutrient particularly suited for mead and wine making.

Fermaid O is a premium organic yeast nutrient developed by Lallemand to support clean, healthy, and complete fermentations in mead, wine, cider, and beer. It’s made entirely from inactivated yeast cells, providing a natural source of organic nitrogen, amino acids, peptides, sterols, vitamins, and minerals, with no added cheap DAP or inorganic ammonia based nitrogen in the formulation like most other yeast nutrients.

Formulated after years of research, Fermaid O provides yeast with the most effective balance of nutrients for optimal kinetic and sensory performance. It promotes steady fermentation, enhances aromatic complexity, and reduces the risk of sluggish or stuck ferments.

Fermaid-O can help to increase the expression of aromatic esters and yeast flavour compounds. When using Fermaid-O you can expect a more steady nitrogen uptake and less temperature peaking when compared to traditional inorganic nitrogen sources like DAP or DAP and nutrient blends. 

Why Yeast Nutrients Matter

During fermentation, yeast convert sugars into alcohol and CO₂ but they also need essential nutrients for growth and metabolism. Without them, fermentation can slow down, stall, or produce unwanted off-flavours and sulfur compounds (particularly in wine, ciders and mead where there is little YAN, vitamins and minerals).

Fermaid O provides these key building blocks:

• Highly bio-available amino-acids and peptides - Amino-acids are more efficiently used by yeast than inorganic nitrogen sources such as DAP.
• Natural sources of survival factors to help yeast in stressed conditions.
• Natural sources of essential micronutrients such as as vitamins (thiamine, biotin, panthotenic acid) and minerals (magnesium, manganese, zinc).

Unlike other inorganic nutrients, Fermaid O releases nutrition slowly and evenly, supporting yeast throughout fermentation and reducing stress. The result is a smoother, cleaner fermentation with improved flavour balance, lower risk of H₂S, and reduced aging time.

Benefits

• 100% organic nitrogen source (no DAP or ammonia salts)
• Steady, healthy fermentation with reduced risk of off-aromas
• Improved mouthfeel, balance, and flavour stability
• Boosts aromatic ester formation for more expressive wines and meads
• Ideal for mead, wine, cider, and high-gravity beer
• OMRI Listed, and registered with ACO and BioGro for organic compliance

Usage Guidelines

Dosage: 10 - 40 g/hL (1 - 4 g per 10 L)
The exact dosage required is dictated by ABV and yeast strain. Some yeast strains have a higher nutrient need than others. If you are unsure target a mid range dosage. As a general rule higher ABV fermentations also require more yeast nutrition for a healthy ferment.

We also suggest splitting your yeast nutrient additions into 2 or 3 doses. Add one addition with the yeast at the start of fermentation and another at 1/3 of the way through fermentation and another at 2/3 of the way through fermentation. This is known as a staggered nutrient addition.

Before adding to the ferment rehydrate the Fermaid-O in 10x its weight of clean water. Mix this solution to remove lumps and add directly to the degassed must.

A 40 g/hL addition provides approximately 17.2 mg/L of actual YAN. This is equivalent in performance to about 48 mg/L of inorganic YAN, as organic nitrogen is 2.5x more efficient for yeast metabolism than inorganic. If your recipe or spec uses inorganic YAN divide the dose by 2.5 to work out your dosage of Fermaid-O.