Koji processing method

A. Oryzae, o Koji

Whenever there is a natural phenomenon, humans try to control it and nature adapts to us. We see this mechanism in agriculture, animal husbandry, architecture, and many more innovations that man has created.

Through this control and adaptations, nature reacted after humans domesticated those crops. Some of the results that have occurred in history are very large, others microscopic, such as the adaptation and domestication of a filamentous fungus, a mold called Aspergillus Oryzae. This adaptation resulted in a genetic change, which went through a genetic mutation for almost 9,000 years. This was a product of mankind's domestication of rice and the plethora of evolutionary opportunities.


This filamentous fungus, A. Oryzae, shares 99.5% of its genetic material with Aspergillus flavus, its ancestral species. With its adaptation, the A. flavus changed. The diffuse mold growing on steamed rice produced aromas described as grapefruit and mango, pulling starches out of the grain via the enzyme amylase and producing amino acids. Through repeated efforts and ample opportunity, mankind domesticated the mold that grew on domesticated rice, then bred and reproduced it, and then sold it through traditional methods passed down for generations in China and Japan. Today, it is known as koji and has been produced for generations by a small number of producers.



The fermentation of koji is unique: instead of producing alcohol, carbon dioxide, or organic acids, koji can transform its substrate differently from yeast or bacteria. Depending on fermentation conditions, koji produces varying proportions of amino acids, such as glutamate. The proportions in which each metabolic by-product is produced depend on the strain of koji and the temperature.


As for coffee, koji serves as a processing agent. But for our purposes, koji would serve as a processing agent, sacrificing polysaccharides and complex starches. All of this makes them available for secondary fermentation by other microbes, as well as for enzymatic processes within the coffee itself, while also producing glutamates that improve cup structure.



The fermentation time in the process is quite fast. It only takes 12 to 16 hours, and sometimes up to 60 hours. To achieve success in the process and for the effects of koji to be detectable, the conditions must be just right. The cherry must be cleaned to drive back other populations by heavily inoculating, and temperature and humidity must be controlled to ensure mold growth.


Together with Kaapo, with support from Koichi-san and Jeremy, the Forest team implemented the process of using koji to process coffee. All to use the results at the WBC. Kaapo competed using the dry process protocol to be called (supernatural Koji process) or Java cherry inoculated with MSCO-11 koji.


If you want to know in detail the whole process developed by Kaapo we invite you to read the complete post on Christopher Feran's blog: https://christopherferan.com/2021/10/23/coffee-koji-and-kaapos-wbc-routine/




What was the process like?


According to Christopher, ''Processing is a transformative step in the value chain, no doubt. Quality is not energy: during processing, quality can be created, maintained, or destroyed''.

In his blog he wonders about the quality of the glasses, but does that value translate into economic security? And what about boutique lots, exotic varieties, and experimental processes, such as koji processing?


''The market for these coffees has developed such that I can now talk to almost any specialty importer and, within a few business days, cup a battery of anaerobic coffees. But as these coffees have become available, has the welfare of coffee producers fundamentally changed? Has the calculus of global commodity trade been short-circuited by their mere existence?''


Most producers with market access have taken advantage of these experiments to obtain higher premiums for those lots, this is a fraction of the market and usually a fraction of a producer's production. For every success, how many product failures can a producer endure? Most consumers do not value batches, either for their exotic flavors or for their rarity, unlike roasters, who do.


Tim Heinze, from Sucafina, says ''Even though they take up airtime on Instagram, at the WBC and at high-end roasters around the world, so-called "experimental processes" represent far less than 1% of the total coffee supply.''


There is a compelling case to be made that there is a place for boutique processing in the value stream and portfolio of coffee producers. The protocol designed for this coffee has been executed by our Processing Director, Elias Bayter. This process requires no more complexity than a typical temperature-controlled cherry fermentation and careful drying.

Together with the Forest team, in one of our farms, EL VERGEL, we were able to produce a delicious coffee and found a new and reproducible way to achieve a quality coffee with less effort and less ongoing costs than those required by other methods or microbes. This was a coffee that took everything we liked about classically processed coffees: a clean, bright, structured, uniform coffee, with elegant, well-integrated, balanced, and amplified fruity tones. It has everything that is great about the flavors of elevated coffees but elevated to the maximum. We were able to create a competition coffee, which could change what has been seen in recent years. This process and protocol devised do not require any special equipment or training and can be applied on any farm, anywhere in the world.

This also allows producers to learn more about how to refine coffee, and create a distinctive cup, which in the end will help to fix the coffee economic system by finding better ways to produce coffee.



At Forest we call it Koji, a coffee that can be customized and chosen by each appraiser, choosing the profile and the process by which they want their coffee to be developed. This gives the opportunity to have a coffee completely unique and tailored to the tastes and needs of the client.



Click here and fill out the form to order your own koji coffee!

Do you want to know more about this coffee and its history and process? Contact us and we will be more than happy to tell you everything a guide you through the process of your customized Koji coffee!


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