How is active dry yeast produced?


How Does Fermentis Produce Active Dry Yeast?

Yeast is a living unicellular microorganism belonging to the eukaryotes (i.e. made of cells containing a nucleus and other organites), about one hundredth of a millimeter in size, so it is not visible to the naked eye.

The scientific name for brewer’s yeast is Saccharomyces Cerevisiae. It comes from the Latin roots ‘saccharo’, meaning sweet or sugar; and ‘myces’ meaning fungus.

Yeast grows with and without oxygen. When nutrients are present, the yeast will multiply by duplication of its genetic material and budding. As a yeast factory, we use this mechanism to produce yeast, also called biomass.

Each production starts with a cryotube containing pure yeast stored at -80°C in our Yeast Strains Bank held by our Research & Development Department. In our laboratory, the yeast cells are selected under strictly controlled conditions and propagated step by step: this is called multiplication. This small amount of any yeast strain produced in our labs then goes to our factory,
where it is propagated until we have enough so-called “mother yeast” that we introduce in larger-scale commercial/industrial size fermenters in which the yeast will grow on a sugar source, primarily molasses.

In these large fermentation tanks, nutrients and vitamins – amongst others – are gradually added along with large amounts of sterile air in a fed-batch process. The challenge and know-how in this part of the process resides in the optimal shaping of the majority of the yeast population in its best condition, throughout the reproduction cycles during the multiplication process, for optimal subsequent drying results with preservation of all original properties of the yeast.

After the “propagation/multiplication” (also often misnamed “fermentation”), the yeast is fully grown, and the suspension is centrifuged to concentrate the yeast. It can finally be processed into three types of yeast products: liquid yeast (about 25% dry matter), compressed or crumble yeast (about 32% dry matter), and Active Dry Yeast (ADY) (over 95% dry matter).

The liquid yeast, also called cream yeast, is obtained by centrifugation as it comes straight out of the fermenters and needs to be kept cold to maintain its stability. The yeast can then be further concentrated into a “solid” yeast paste called compressed yeast, by vacuum filtration. The final stage is the further drying of the yeast with a fluidized bed technology that carefully dries the yeast with hot air to a final dry matter amount of up to 96.5%.

This is how we obtain Active Dry Yeast!

Our expertise at Fermentis allows a full conservation of the original yeast strain’s properties that are essential for proper fermentation, making it essentially the “freshest” form of yeast, while increasing at the same time the shelf-life, stability and ease of use.


The world of fermentation is now a click away! The Fermentis application is available on both Apple Store and Android Store.

As a brewer, you will be interested in exploring new sensory pathways, fine-tuning the originality of your aromas, or perhaps exploit fermentation potential of your wort at its best. That’s why we are proud to introduce you to the Fermentis app…

  • Find technical data about our products
  • Be geo-localized and find the nearest distributors
  • Discover our fermentation tools including converters, yeast advisor, ABV and attenuation calculators and many more to come
  • Enter into our world and discover our different brands
  • Want to get in touch with our experts or give us your feedback? Two possibilities: directly through the app or through our social networks!

Download it below by clicking on the link or by scanning with you camera application:

Apple Store

Google Play Store

Back to Tradeshow

Latest