Koji.

What happens when an ancient mould hangs out with coffee for a while?

How many times have you opened the fridge, popped the top off your pesto and said - “that looks slightly more cultured than me”- One thing I have never done but, ought to try, is to scoop the little furry white caterpillar from the jar and explore what delicacies lie beneath.

The idea of mould, bacteria and fungus metabolising our sweet and savoury accoutrements is enough to turn most stomachs into churning furnaces but, as they say, “ what you don’t know won’t hurt you” and what you don’t know, could be leading to flavour nirvana…

Photo by Zoltan Tasi on Unsplash

Now, I am not endorsing the fact that you should all start enjoying mouldy pesto. Although my wife doesn’t seem to mind (I believe this is more for economic reasons) I do think we need to be aware that some of the staples we find in our kitchen cupboards have spent a considerable amount of time in an inoculated state, in order to enhance our sensory perception, and the deeper I dive into the world of fermentation, the more interesting my eating habits have become.

I remember my first encounter with a coffee-drying table, the ripe, red cherries had just started to decompose and what looked like a light film of fuzzy hair had started to map its way across the skin. To the novice eye, this looked suspicious but to the experienced hand, this was magic taking place and as the coffee was turned, making sure the cherries would evenly dry, the smell was intoxicating, almost to the point that if I was to close my eyes, I could have placed myself at a banquet table being served the world’s most eclectic feast, where exotic fruit, fortified wine, aged meat, ancient cheese, and athlete’s feet were all on the menu. How this is then transferred to the end cup is something I am still trying to figure out, and I have a feeling, like everything in my life that has provided me with a desirable result, it is going to take me some time.

What is Koji?

KOJI is a domesticated mould culture (Aspergillus oryzae), known as “kikōji-kin” in Japanese, that is grown on rice and used as a starter for fermenting some of the best-known and very delicious Japanese and Chinese food and beverages, these include sake (Japanese rice wine), honkaku shochu (a Japanese distilled liquor), amazake (a nonalcoholic sweet rice drink), soy sauce, miso (fermented soybean paste), mirin (sweet sake for seasoning), rice vinegar, salted koji, and pickles.(Yamashita, H, 2001) The spores are grown deliberately on steamed rice, which if left at the right temperature, for the right amount of time, will invite native occurring yeast and bacteria in the atmosphere to adhere to the rice and so begins the growth of fermented bacteria, which is then harvested and used to inoculate other foodstuffs to provide us with the rich, savoury and heavy-bodied umami flavours that this process is famed for.

There is obviously more scientific wonder at play here and countless RESEARCH has been applied to the field of Koji mould with some of the biggest NAMES in the culinary world harnessing its powers to create incredible dishes and so, with my limited knowledge of the subject, my desire to learn more and the vast amounts of literature I have been consuming, I will try to organise my thoughts and place them in this article.

In essence, During Koji fermentation, the Aspergillus oryzae fungus breaks down the starches in the cooked grains (mostly rice but sometimes barley) into simpler sugars such as glucose, fructose, and maltose. This process is known as saccharification and is carried out by enzymes that are produced by the fungus. The breakdown of the starches into simpler sugars is an important step because it makes the sugars more accessible to other microorganisms during subsequent fermentation steps.

In addition to saccharification, the Aspergillus oryzae fungus also produces a range of other enzymes, including proteases, lipases, and amylases. These enzymes break down proteins, lipids, and complex sugars into simpler molecules that are more easily fermented by other microorganisms.

The final product of Koji fermentation is a mixture of partially digested grains and enzymes that are rich in amino acids, sugars, and other nutrients and this forms the building blocks for new and incredible aroma and flavour compounds to be created, these are often described as rich and savoury (umami) with aromatic qualities of tropical and citrus fruits and offer a depth of complexity that only something that has undergone control fermentation can achieve.

Here are a couple of ARTICLES that I found incredibly useful whilst doing my RESEARCH and I am now debating whether or not I should create my own starter, although I am not quite sure that my brain can afford another OBSESSION.

So what does this have to do with coffee?

Late last year I received a few samples for a project I was working on with JONNY MARTINEZ (who I mention in a previous POST) we were looking for some coffees to showcase at an event in Manchester and he mentioned that his close friend and world-renowned coffee producer WILTON BENITEZ was working on some fermentation protocols using Koji spores. Wilton was using a strain of Koji to inoculate coffee cherries after harvest and was seeing incredible results. This was in the very early stages of experimentation but he asked if I would be interested in trying. My answer was obviously a resounding YES as you might imagine, and let’s just say, what I received and tasted, once again challenged my theories of what can be achieved when it comes to coffee flavour.

However, what has ultimately led me to write this article, is the fact that as I was searching through my endless boxes of sample material, I just happened to come across a few grams of the green coffee above, which must have been packed away after the event so, I thought I would roast it up and share my results here.

As you can see the coffee scored incredibly high at 90 points and is one of only a handful of coffees that I have had the pleasure of tasting and scoring this high, and the truth of the matter is, I am not quite sure where all of this is heading. What I do know is this, if this level of complexity and flavour can be created through alternative forms of fermentation, using techniques that have been around for centuries, then we have a duty as specialty coffee advocates to explore this further. Oh, and I will also be having MISO SOUP for dinner…

I will report back on these matters as I learn more.

What a week!

Cheers

Burts