FAQs

What is YAN?

Why should I use Go-Ferm?

When should I add Go-Ferm? How much should I use? 

When should I add Fermaid K? How much should I use? 

Should I use Diammonium phosphate (DAP)? When should I add it? 

How do I test for nitrogen levels in my juice/must? 

I have an organic wine program. Which yeast nutrients can I use? 

What is the difference between Fermaid K and SIY 33 (Fermaid 2133)? 

When should I use yeast hulls? 

Which nutrients are considered Kosher? 

How much nutritional value does Opti-RED add to the juice/must?

Why are pantothenate and magnesium sulfate important to yeast cells?

Do different yeast strains require more nutrients than others do? 

Is nutrient addition timing important? Why? 




 

What is YAN?


YAN stands for Yeast Assimilable Nitrogen. It is the sum of assimilable nitrogen from ammonium ions and the assimilable Free Amino Nitrogen (FAN) present in the juice/must. Low levels of YAN are associated with the production of undesirable sulfide compounds. Recommended levels range from 250 ppm-350 ppm or higher depending on the initial Brix level.

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Why should I use Go-Ferm? 

Go-Ferm immediately gives your desired yeast a leg up over other organisms during fermentation. Go-Ferm is added to the rehydration water of the selected active dried yeast. A "sponge effect" allows the yeast to soak up the nutrients as they soak up the water. Micronutrients are more bioavailable to the yeast, which encourages a strong and smooth fermentation.

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When should I add Go-Ferm? How much should I use? 

Go-Ferm should be added in the rehydration water of the active dried yeast prior to the yeast addition itself. The recommended dose is to add 2.5 lb Go-Ferm/1000 gal (of total juice/wine) into 20 times its weight of clean 43°C(110°F) water. Stir the GoFerm to dissolve. For optimal performance, maintain a ratio of 1 part yeast to 1.25 part Go-Ferm.

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When should I add Fermaid K? How much should I use? 

Fermaid K is best added at 1/3 of sugar depletion at a rate of 2 lb/1000 gal. Fermaid K should be hydrated before adding to an active fermentation to avoid CO2 release and overflowing of tanks or barrels.

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Should I use Diammonium phosphate (DAP)? When should I add it? 

DAP should be used when YANC is below 125 mg N/L. Fermaid K contains some DAP, but for very low Nitrogen content must, DAP is recommended to bring YANC to above 150 mg N/L. Each 2 lb/1000 gal (25 g/hL) addition yields 50 mg N/L inorganic (ammonium) nitrogen.

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How do I test for nitrogen levels in my juice/must? 

Levels can be tested through formol titration or the NOPA method. Inorganic nitrogen can be determined by using an ammonia probe.

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I have an organic wine program. Which yeast nutrients can I use? 

Some nutrients do not conform to organic qualifications while others are tailored for this purpose. For organic wine, we suggest Go-Ferm, Go-Ferm Protect, Fermaid O or SIY 2133 (Fermaid 2133).

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What is the difference between Fermaid K and SIY 33 (Fermaid 2133)? 

SIY 33 (Fermaid 2133) is a whole yeast cell powder providing amino nitrogen and B vitamins. Fermaid K is a blended complex yeast nutrient containing Magnesium Sulfate, Inactive Yeast, Thiamine, Folic Acid, Niacin, Biotin, Calcium Pantothenate and DAP.

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When should I use yeast hulls? 

Use yeast hulls to fine out toxins in the case of sluggish/stuck fermentation, to increase the surface area of clarified juice, and to supplement survival factors such as sterols.

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Which nutrients are considered Kosher? 

The only nutrient that conforms and is documented as Kosher is Fermaid K (Kosher).

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How much nutritional value does Opti-RED add to the juice/must? 

Opti-RED is basically a highly specific form of autolyzed yeast. There is some benefit derived from this organic nitrogen source, but the use of Opti-RED should not preclude the use of other nutrients like Fermaid K, Go-Ferm or Go-Ferm Protect.

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Why are pantothenate and magnesium sulfate important to yeast cells?

Pantothenate helps to keep open important metabolic pathways that dramatically reduce the production of H2S. Magnesium improves yeast alcohol tolerance.

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Do different yeast strains require more nutrients than others do? 

Yes. Each strain has distinct fermentation kinetics. One strain may require less of one nutrient compared to another strain. Do your research. See the individual product descriptions to help determine your yeasts' specific needs.

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Is nutrient addition timing important? Why? 

Yes. Yeast metabolize nutrients at different times throughout fermentation. Dosing nutrients at the most optimal moments can enhance yeast performance. As fermentation progresses and the ethanol level rises, yeast becomes less and less able to assimilate nutrients. For this reason, each nutrient has been created for specific addition times. For example, GoFerm has been designed to add during rehydration. Other nutrients like Fermaid K are added at one-third sugar depletion and never into the rehydration water.

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