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When and how to use yeast nutrient for brewing

brewing with yeast nutrients

Yeast, that magnificent beast of an organism that converts sugars to alcohol, is the key to fermentation.

Fermentation itself a fairly straightforward process but there are a lot of variables at play to ensure that you get a good tasting beer, let alone a brew that tastes like you intended!

Temperature, time, pH levels and oxygen are key factors.

An overlooked one is often yeast nutrition.

Does your yeast need nutrients? 


The malt in your beer is usually enough to sustain the yeast cells but in order to thrive (and thus efficiently ferment your beer wort and achieve a high attenuation) other elements such as levels of free amino nitrogen, fatty acids, and even vitamins and other minerals come into play and become factors in a successful brew. 

The truth is though, you could do a hundred brews and never need it but if you a looking for high attenuation rates or a brewing a beer with a high ABV, it may help as you need a strong yeast to achieve those two goals.  

When should I use a yeast nutrient?


You may also consider using a nutrient if your water is lacking in calcium, magnesium, and zinc as these metals. Zinc can help with the cell count while magnesium helps with cellular metabolism.

If your beer is using a high proportion of 'adjuncts', you'll want to consider supporting the yeast too. Sugar alone does not support the yeast so if there's a higher concentration of sugars in your beer, then a nutrient may assist yeast development. 

If you are making wine or cider or mead, you would be more likely use nutrient as there is less for the yeast to make do with than in the malty beer wort. Honey,. for instance contains no nitrogen.

To cover some of these factors off, many home brewers choose to add yeast nutrient to their beer batch.

The other benefits of adding a yeast 'energizer' include the shortening of the 'lag phase' of fermentation can contribute to a reduction in off-flavours in beer or wine.

Yeast food may also help reduce the final gravity by invigorating the yeast pushing it to a more complete fermentation leading to a reduction of diacetyl or acetaldehyde (that apple flavour). 

There are three modes of yeast nutrition:


  • Nitrogen supplements -  usually in the form of di-ammonium phosphate which is a water soluble salt and or urea, this should be used when there's a lack of free amino nitrogen. Can be used for mead, cider, wine, and beer. Fermax and Fermaid are popular brands used by brewers as it contains the phosphate as well as magnesium sulfate and autolyzed yeast
  • Yeast hulls - dead yeast of which the residue acts as a home for live yeast. Live yeast will eat the hulls and feed on the nutrients contained therein. 
  • Yeast energizers are used to stimulate or restart a stalled fermentation.

Can I add yeast nutrient to my starter?


You sure can. Brewers will often add about a quarter teaspoon to their starters. Bread bakers have been known to add it to their sourdough starters!

When should I add yeast nutrient to my brew?


It should usually be added at the start of fermentation. If you are using an energizer you will most likely be adding it when fermentation has failed or halted. 

How much yeast nutrient should I add?


Manufacturers typically recommend 1 gram per litre or 1 teaspoon for 5 litres/1 gallon. There should be instructions on the packaging.

What are Servomyces?


This is a yeast supplement produced by the famed yeast developers, White Labs. They boast that 

"Servomyces enables any yeast strain’s ability to incorporate essential nutrients into its cellular structure. It is propagated in a micronutrient rich environment and then killed off prior to packaging.  
Boiling incorporates the servomyces into the wort. The benefit of servomyces is that micronutrients, e.g., zinc are able to pass through its cell walls to your live cell yeast cell, thereby delivering the micronutrients without toxicity."
Check out what White Labs have to offer on Amazon.

So if you batch is short of zinc, then using Servomyces may be the right option for you. If you are doing a boil, it is recommended you add one capsule ten minutes prior to the end of the boil. If doing a kit brew, you can open the capsule up and add the Servomyces directly to the wort. 

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