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Fermentation Nutrition Planner

Last updated: 6/2021

Applies to: winemakers supplementing yeast available nitrogen (YAN) and nutrients during alcoholic fermentation. Contains a pdf download of this protocol at the end of the article.

The Importance of Yeast Nutrition

To conduct a healthy and complete fermentation, yeast require minerals, vitamins, fatty acids, sterols and nitrogen. Minerals, vitamins, fatty acids and sterols are provided by GO-FERM PROTECT EVOLUTION™, whereas nitrogen is supplied by FERMAID O™ or FERMAID K™. Yeast also use essential nutrients to stimulate certain metabolic pathways resulting in increased wine aroma. The STIMULA™ range of nutrients both nourishes the cells and stimulates metabolic pathways to increase aromas and flavors.

Protocol

Use the following step-by-step guide to develop a complete yeast nutrition program for each fermentation goal. This planner accounts for the individual needs of the yeast, how much fermentable sugar is present, and how much nitrogen is required by the yeast for the desired wine goal.

1. Choose the yeast strain. Strains are classed as low, medium or high nitrogen-need.

2. Measure sugar (Brix) and YAN in juice/must.

3. Determine the yeast strain's Measurable YAN requirement using Table 1.

4. Calculate the amount of Measurable YAN that needs to be supplemented: [Yeast Measurable YAN Requirement (using Table 1)] – [ Measurable YAN of Juice or Must] = Amount of YAN Required to Supplement (ppm)

5. Determine fermentation goal and follow program as outlined below:

pdf Download

Download a printable version of this protocol below

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Which STIMULA™ should you use?

Despite their names, STIMULA™ nutrients can be used in almost any variety to help achieve a desired wine style. Which STIMULA to use depends on whether fruity esters or tropical, floral or spicy aromas are desired.

Stimula Chardonnay and Stimula Cabernet for Fruity Esters

Esters contribute sweet-fruity aromas and flavors in white, rosé and red wines. It is the synergy of esters that contributes to overall complexity of wine aromas. Recent research has shown that ester production happens in two phases with the majority of esters produced during last two thirds of fermentation.

Fermentation esters can be split into two major groups: acetate esters (responsible for rose/floral aromas) and ethyl esters, responsible for red berry/fruit aromas. Although yeast vary in their ability to produce esters, ester production is highly influenced by nutrient composition and fermentation conditions. Lipids, vitamins and specific amino acids all support ester production which is why STIMULA CHARDONNAY™ is recommended for all fruity and floral white and rosé wines and STIMULA CABERNET™ is beneficial for all red wines where enhanced red and black fruity aromas are desired.

Stimula Sauvignon Blanc and Stimula Syrah for Enhanced Varietal Character

Thiols and terpenes are aroma molecules that contribute to a wine's varietal character. Most grapes and the resulting wines differ aromatically. This may be due to the release of varietal aromas or the production of fermentative aromas. Varietal aromas (precursors) are often odorless and flavorless. It is the action of yeast during fermentation that are partly responsible for releasing varietal aroma compounds. Once released these compounds are described as tropical, citrus, grassy, floral, fruity and/or spicy.

More specifically, most Saccharomyces yeast can take up aroma pre-cursors, however only certain yeast strains with specialized enzymatic ability (β-lyase, β-glucosidase) can release the odor-active compound. STIMULA SAUVIGNON BLANC and STIMULA SYRAH provides yeast with the key micronutrients at the right time for enzyme synthesis.

In white and rosé wines STIMULA SAUVIGNON BLANC™ helps yeast release thiols increasing tropical notes of passion fruit, guava and grapefruit. In certain grapes grassy, boxwood and citrus aromas can be revealed. In red wines STIMULA SYRAH™ increases blackcurrant, floral and spicy aromas from bound thiols and terpenes. STIMULA SAUVIGNON BLANC can be used in any varietal from Sauvignon blanc to Pinot gris and Chardonnay whereas or STIMULA SYRAH can be used in most red cultivars including Pinot noir, Grenache, Merlot or Syrah. The possibilities are endless!

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