NUTRIENTS FOR ALCOHOLIC FERMENTATION
Since Lallemand began producing yeast in the early 20th century, we have understood the importance of providing growing yeast the nutrients they need to survive and reach their maximum potential. Experiences in our own yeast production fermentations laid the groundwork for our nutrient formulations. We have also collaborated with others in the area of yeast growth nutrition and fermentation to attempt to understand the complex and often frustrating interactions in grape must.
Lallemand offers three classifications of yeast fermentation nutrients:
• 1. Nutrients and Protectants Added to Yeast Rehydration Water
• 2. Complex Yeast Nutrients for Use During Fermentation
• 3. Other Yeast Nutrients for Use During Fermentation.
Nutrients and Protectants Added to Yeast Rehydration Water
GO-FERM® -- OMRI listed
Lallemand’s collaboration with the INRA in Montpellier and other institutes throughout the world confirmed the critical role of yeast micronutrients, but more importantly, it identified the most effective way to ensure that these micronutrients benefit the selected yeast.
The result of this research was the development of GO-FERM®, a natural yeast nutrient to avoid sluggish and stuck fermentations. GO-FERM® is specific inactive yeast produced through a unique yeast biomass process fine-tuned to obtain high levels of certain essential vitamins, minerals and amino acids required for healthy yeast fermentations.
The GO-FERM® approach is to provide bioavailable micronutrients in the non-stressful environment of the yeast rehydration water instead of the traditional method of adding micronutrients to the must. During rehydration, the yeast acts like a sponge, soaking up GO-FERM®’s bioavailable nutrients. This direct contact between GO-FERM® and the yeast in the absence of the must matrix avoids chelation of key minerals by inorganic anions, organic acids, polyphenols and polysaccharides present in the must. It also prevents essential vitamins from being rapidly taken up by the competitive wild microflora or inactivated by SO2. By making key minerals and vitamins available to the selected yeast at the critical beginning of its stressful task, the yeast’s viability increases and fermentations finish stronger.
The use of GO-FERM® results in significantly better overall health of yeast cells through-out the fermentation, affecting fermentation kinetics and resulting in a cleaner aromatic profile.
Dosage recommendations: Use 30 g/hL (2.4 lb/1000 gal) of GO-FERM® when rehydrating yeast to supply critical micronutrients. Note: This recommendation is based on a yeast inoculum of 25 g/hL (2 lb/1000 gal). If using more or less yeast, respect a ratio of 1 part yeast:1.25 parts GO-FERM®.
NEVER USE NUTRIENTS CONTAINING AMMONIA SALTS SUCH AS DAP DURING YEAST REHYDRATION - THEY ARE TOXIC TO THE YEAST AT HIGH LEVELS!
GO-FERM PROTECT® -- OMRI listed
Through the NATSTEP™ process, GO-FERM PROTECT® optimizes the micronutrient bioavailability of GO-FERM® with the added benefit of survival factor protection. These survival factors include specific sterols and polyunsaturated fatty acids that strengthen the yeast membrane during rehydration making it more resistant to fermentation stress. GO-FERM PROTECT is used in the yeast rehydration water to create a suspension of micronutrients and survival factors that are bioavailable for selected yeasts. GO-FERM PROTECT is recommended in place of GO-FERM® for very difficult fermentation conditions, such as:
- 1. High maturity conditions (>25° Brix) to help protect yeast against osmotic shock helping avoid high VA production during fermentation.
- 2. High potential alcohol conditions to help protect yeast against alcohol toxicity helping avoid sluggish fermentation finishes.
- 3. Over clarified juices to help supply key yeast survival factors.
- 4. Restarting stuck fermentations to protect and condition the “rescue yeast” against high alcohol conditions.
Dosage recommendations: Use 30 g/hL (2.4 lb/1000 gal) of GO-FERM PROTECT™ to stimulate and protect the rehydrating yeast.
Note: This recommendation is based on a yeast inoculum of 25 g/hL (2 lb/1000 gal). If using more or less yeast, respect a ratio of 1 part yeast:1.25 parts GO-FERM PROTECT™.
Complex Yeast Nutrients for Use during Fermentation
Initially developed specifically for the Australia and New Zealand wine industries as a yeast fermentation nutrient since Nitrogen is of primary importance to the wine yeast during fermentation. The available yeast assimiliable nitrogen (YAN) in the must/juice directly impacts the fermentation rate and formation of flavor active volatile compounds. Fermaid A contains inactivated yeast (organic YAN; alpha-amino nitrogen) and diammonium phosphate (inorganic YAN). The inorganic/amino nitrogen mix is aimed at encouraging a more balanced metabolic fermentation outcome. The elevated intracellular amino nitrogen reserve resulting from Fermaid A addition, assists the yeast to manage alcohol fermentation more effectively to completeness without prolonging the toxic exposure to alcohol as a result of a sluggish end of fermentation. Note: Yeasts rehydrated in Go-Ferm Protect especially benefit from the timed addition of Fermaid A at 1/3 sugar depletion. Dosage rates are dependent on initial juice/must YAN.
The original and reliable FERMAID® K is a blended complex yeast nutrient that supplies inorganic nitrogen (DAP), organic nitrogen (alpha amino nitrogen derived from yeast extract), key nutrients (magnesium sulfate, thiamine, folic acid, niacin, biotin and calcium pantothenate) and inactivated yeast.
It is best to add FERMAID® K over two additions. The first addition is made at the end of the lag phase (6 to 12 hours after yeast inoculation) and the second addition is made around 1/3 sugar depletion (the end of exponential growth and the beginning of the stationary phase).
With proper rehydration and handling, the yeast cell population should be at least 4 million cells/mL at inoculation. By the time the second FERMAID® K addition is made, this population should have grown to about 100 million cells/mL. It is critical to remember that yeast are still reproducing during the stationary phase, and to do this effectively, especially in high sugar musts, they need oxygen as well as the components of FERMAID® K, including nitrogen (for protein synthesis), sterols and fatty acids (for maintaining alcohol resistance and permease activity). In addition, the inactivated yeast cell walls in FERMAID® K adsorb medium-chain fatty acids that are toxic to yeast, and provide nucleation sites to help keep the yeast in suspension.
If Fermaid K complex yeast nutrient is used, the recommended dosage is as follows:
- Add 12.5 g/hL (1 lb/1000 gal) FERMAID® K at the end of the lag phase (beginning of alcoholic fermentation).
- Add 12.5 g/hL (1 lb/1000 gal) FERMAID® K around 1/3 sugar depletion.
-- OMRI listed
Fermaid O is the latest nutrient developed by our winemaking nutrient research team headed by Dr. Anne Ortiz-Julien. Fermaid O is a blend of inactivated yeast fractions rich in organic nitrogen. Fermaid O does not contain added ammonia salts (DAP) or micronutrients. The importance of organic nitrogen from yeasts is well known as a highly efficient nutrient source for wine yeasts, especially when compared to inorganic nitrogen from DAP. In addition, Fermaid O consistently produces lower levels of negative sulfur compounds, compared with DAP. With its high content of organic nitrogen, Fermaid O can help winemakers achieve steady fermentations, while limiting temperature peaks. When inorganic nitrogen (DAP) additions are NOT desired, the use of Go-Ferm® or NATSTEP™ and Fermaid O is recommended. With this combination, Go-Ferm or NATSTEP provides needed micronutrients during yeast rehydration, and Fermaid O (when added at 1/3 sugar depletion) supplies critical nutrients and survival factors to help the yeast avoid stressed conditions.
Note: In low nutrient situations, yeast available nitrogen may be insufficient to avoid fermentation problems. Dosage recommendations: Add 40 g/hL (3 1/2 lb/1000 gal) of Fermaid O, 20 g/hL at the end of the lag phase and another 20 g/hL around 1/3 sugar depletion.
NUTRIENT VIT END™
-- OMRI listed
NUTRIENT VIT END is a new specific inactivated yeast, developed by the Lallemand Research and Development group for use in avoiding and/or treating sluggish and stuck fermentations. Low yeast viability is a common problem in alcoholic fermentations, and may be caused by the presence of residual fungicides and/or short- and medium-chain saturated fatty acids, such as hexanoic, octanoic, decanoic and dodecanoic fatty acids and their esters. The production of these saturated fatty acids by yeast is favored by stressful fermentation conditions, which can arise with low juice turbidity, very high initial sugars, the condition of the selected yeast, or extreme fermentation temperatures during the later phase of fermentation. Saturated fatty acids modify the yeast sugar transport capacity by interfering with the membrane sugar transport proteins. NUTRIENT VIT END is a specific inactivated yeast that has very high bio-adsorptive properties for saturated short- and medium-chain fatty acids and fungicides. With these properties, NUTRIENT VIT END helps secure the end of alcoholic fermentation.
Note: Although NUTRIENT VIT END provides a minor supply of yeast nutrients, such as organic nitrogen, it does not replace the regular nutrition program integrating juice parameters and the nutritional needs of yeasts. Preventive dosage: At the very beginning of fermentation, add 30 g/hL of NUTRIENT VIT END to juice or must. Curative dosage: With a sluggish or stuck fermentation, add 40 g/hL of NUTRIENT VIT END to the wine and let settle then rack off before inoculating with rescue yeast.
Other Nutrients for Alcoholic Fermentation
SIY33 is pure autolyzed, spray-dried yeast providing alpha amino nitrogen, B vitamins and the benefits of yeast cell walls to help sluggish or stuck fermentations. SIY33 will help supplement the alpha amino nitrogen component of yeast available nitrogen (YAN). Unlike FERMAID® K and FERMAID A, SIY33 does not contain added ammonia salts (DAP) or micronutrients.
When inorganic nitrogen (DAP) additions are NOT desired, the use of GO-FERM® or GO-FERM PROTECT® and SIY33 is an option. With this combination, GO-FERM® or GO-FERM PROTECT® provides needed micronutrients during yeast rehydration, and SIY33 (when added at 1/3 sugar depletion) supplies critical nutrients and survival factors to help the yeast avoid stressed conditions. Please note: In low nutrient situations, yeast available nitrogen may be insufficient to avoid fermentation problems.
SIY Cell Hulls™
SIY (specific inactivated yeast) cell hulls are a dried preparation of the insoluble fraction of whole yeast cells (i.e., cell wall membranes). Yeast hulls added to the must supply survival factors, such as sterols and unsaturated fatty acids, increase the surface area of over-clarified juice and adsorb toxic compounds. Dosage recommendations: Add 25 g/hL (2 lb/1000 gal) yeast hulls to highly clarified juice, or when preparing the wine before restarting a stuck fermentation.
FNI 100 Dry Yeast Extract
FNI 100 yeast extract is composed of the water-soluble portion of autolyzed yeast cells and contains a high level of organic nitrogen in the form of readily and easily absorbable amino acids and peptides for fermentation nutrients. FNI 100 is especially useful for malolactic bacteria since they are only able to take up nitrogen from organic sources. The amino acids are useful to yeast in juices or musts that are depleted of nutrients or missing specific amino acids.
Dosage recommendations: Standard addition rate for FNI 100 dry yeast extract is 12.5 g/hL (1 lb/ 1000 gal).
FNI 150 Pourable Liquid Yeast Extract
FNI 150 is the easy-to-use liquid version of FNI 100, a primary grown yeast extract. FNI 150 is organic nitrogen in the form of readily and easily absorbable amino acids and peptides for fermentation nutrients.
Dosage recommendations: See above rate for dry yeast extract. 1.9 lbs of pourable FNI 150 is equivalent to 1 lb of the FNI 100 dry yeast extract. Measuring the addition by volume, 660 mL or 22 oz volumes are equivalent to 1 lb dry extract.
Malolactic Bacteria Nutrients
ACTI-ML was developed by the Lallemand bacteria R&D team led by Dr. Sibylle Krieger. For MLF in difficult wines, add ACTI-ML to the bacteria culture’s rehydration water. ACTI-ML is a specific blend of inactive yeasts rich in amino acids, mineral cofactors, and vitamins. These inactive yeasts are blended together with cellulose to provide more surface area to help keep bacteria in suspension.
Dissolve 20 g of ACTI-ML into 100 mL of 25°C (77°F) clean water and then add 1 g of bacteria. Wait 15 minutes and add the suspension to 100 L of wine.
OPTI’MALO® PLUS was formulated to help support MLF in difficult wines. Add OPTI’MALO® PLUS directly to the wine before inoculating with the malolactic bacteria culture. Do not use OPTI’MALO® PLUS during bacteria rehydration. OPTI’MALO® PLUS is a unique blend of special inactive yeasts rich in amino acids, mineral cofactors, vitamins and polysaccharides. These inactive yeasts are mixed together with cellulose to provide more surface area to help keep bacteria in suspension and to help absorb potential malolactic bacteria inhibitors.
Add 20 g/hL (1.6 lb/1000 gal) OPTI MALO® PLUS to a small amount of water or wine and then add directly to the wine anytime from 48 hours prior to or up until the same time as the ML culture addition.