Yeast is a living organism and, as such, needs nutrients and energy in order to do the work of turning crushed

grapes into the perfect wine. Nutrients are like food-substances that make certain the survival of yeast. Ensuring

your wine has the right amount of nutrients helps prevent stuck fermentation and that dreaded rotten egg smell

(Hydrogen Sulfide).

Yeast requires three major nutrients:

• Nitrogen

Responsible for the production of protein which makes new yeast cells.

• Oxygen

Required for fermentation, but especially at the beginning of the process to allow yeast cells to multiply

quickly. Oxygen also helps to create lipids in yeast cell walls which protects against any alcohol toxicity

that can occur near the end of fermentation.

• Micronutrients

These are the vitamins and minerals required by yeast such as: phosphorus, urea, amino acids,

pantothenic acid, citric acid, biotin, and yeast hulls. These micronutrients are only needed in small doses.

Yeast nutrients are easily added to your wine. Winemakers can purchase these at their favourite winemaking

boutique. Coming in various formats, the most common products/sources are listed below:

• DAP (Diammonium Phosphate)

- Provides Nitrogen at 25g/HL = 50mg/L N

- DAP addition of 1 g/L provides about 258 mg/L fermentable N.

- In addition it contains phosphorus.

• Fermax™

- A mix of micronutrients including:

- diammonium phosphate

- dipotassium phosphate

- magnesium sulfate

- autolyzed yeast.

• Fermaid (Also known as Fermaid K)

- Another micronutrient mix with Nitrogen, Fermaid contains:

- amino acids

- sterols

- yeast hulls

- vitamins

- fermentable nitrogen (25g/HL = 25 mg/L fermentable N)

• Yeast Hulls:

- Assists fermentation by using its cell walls to absorb autotoxic yeast byproducts that can slow the

process.