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Coffee Stories

COFFEE STORIES
Part 3: Pushing The Boundaries with Innovation
Part 3: Pushing The Boundaries with Innovation

04 Feb 2022

Due to Covid restrictions and a military coup, this was their first year not having consultants to come and give them advice, or buyers to come cup their coffees with them and give feedback during harvest. Everything was under lockdown, and they could not even ship samples out until the end of harvest. 

“We were in a sense, on our own and yet, the situation pushed us to cup all 313 lots ourselves. Our processing team became experienced cuppers through the process. In the 2020/2021 harvest season, BTL conducted numerous experiments in manipulating fermentations. One of those experiments far exceeded all expectations. As we blindly cupped our experimental lots, one in particular, continually jumped off the cupping table so to speak. So much so that we stopped all other experimentation and focused on fine-tuning this one. It was the favourite every time of all six cuppers, including myself (the one Q grader in the group).”

Processing experiment, yeast and so much more

The story of the winning processing experiment at BTL in 2021 involves the use of “yeast balls” (traditionally used as fermentation starters in local rice wine production). These mysterious little white, starch-based balls are made in isolated Kayah villages using secret recipes that have been handed down generation to generation. One can find similar fermentation starters in other countries in the region and now in Asian grocery stores all around the world. It is often called by its Chinese name Qū or jiuqu or known as starter cakes or rice wine starter. These starters differ from country to country, and even between neighbouring villages.

“The real test would be to send samples out to coffee experts who are experienced with cupping coffees from around the world. Some buyers confirmed that the quality has raised so much and needed to be reflected in the prices. Knowing our international market was willing to pay higher prices for our coffees helped to push a troubled team through impossible days. To hear that the cupping notes and scores given by buyers likened to ours was encouraging. Cupping notes of our new experimental coffee included grape bubble-gum, mango and coconut sticky rice, starburst, tropical punch, candy, juicy fruit flavours, intensely sweet, blueberry, lychee, strawberry ice cream, honey pineapple, round body and very complex."

Melanie is spending the off-season experimenting with her own recipe using rice flour and oriental herbs, roots and leaves indigenous to her area. She is now testing the microbial ball (homemade fermentation starters) in the making of rice wine. The most successful BTL “starters” will then be used in coffee fermentation this coming harvest and will need to be compared with the results of the traditional starters that they can buy in the market.

Keep the (rice) ball rolling

Right now, Melanie is focusing on improving her consistency on processing her 72h anaerobic natural using the native yeast balls, and is learning how to evaluate it, understand it and control it. Melanie and her team have closely monitored temperature and pH and know what to expect in sight and smell. The average temperature of the coffee mass (100kg) inside the drum changed very little in 3 days, was 17-18C on average and the pH when complete was approximately 4.2.

 

“Though we cannot perform a microbial test to know what microbes are prevalent in our drum-fermented naturals, we can conjecture according to the sensory profile. Maybe one day we can have microbiota mapping done at BTL.”

The processing team knows it was an improvement in consistency; they are now able to reproduce a flavour profile and pick it out on the cupping table blindly. They know the aroma and flavours intensified, but they don’t understand how adding the yeast ball to the coffee could affect the flavour like it did. There were other exciting, unexpected benefits from using the solid-state starter that is worth exploring with the team in the training and researching further. When the coffee was taken from the sealed tank, after a 3-day closed fermentation, and spread on the raised drying beds, a visible white, beneficial biofilm dried on the exocarp and seemingly served as a protective cover, suppressing unwanted fungal growth throughout drying and storage, up until milling. When it would rain, other naturals had green mould on the outside, but the coffee fermented with the microbial ball stayed white.

The coffee’s exocarp dried faster, shrinking in size, allowing more space on the drying bed but strangely the drying time of the seed (average of 22 days) did not change and compared with the drying time of a normal dried natural. The colour (greenish in tint) of the seed was visibly better than other natural ferments that tend to be amber colour. Months after milling, this was yet another promising observation.

The coffee hulls/husks from the dry mill were piled in the pear grove, waiting to be composted together with banana trees, cow dung and biochar. When they dug into the pile 2-3 months after dry milling, it was different from past years. This time it was full of mycelium and looked like an untouched forest floor of decomposed organic material.

 

“This is favourable considering we practice Korea Natural Farming (KNF) and spend much time in growing indigenous microorganisms as part of our natural farming.”

 

Since the natural, indigenous starter used in fermentation was never washed away, it is now spreading in their compost pile and available to go back into the coffee farm, aiding the microbiological ecosystem.

 

“It is a perfect example of circular agronomy and reassuring to know that our processing method doesn’t just produce excellent coffee but is environmentally friendly at the same time. These are a few of the key observations that the team needs to see and to look for in doing experiments and performing evaluations.”