Our Merbabu coffee is grown in several small villages, on the slopes of Mt Merbabu in Central Java. Tosoro is the first village that Bright Java begun working with directly, back in 2017. We stumbled on them as we were perfecting our method for finding new origins: randomly drive around on the mountains and start chatting with people. This doesn’t lead us to industrial scale producers who already do exporting. This is the beginning of an ongoing relationship with small producers that leads to community transformation and, incidentally, amazing microlots of unique specialty coffee.


This village, it turned out, had received Arabica seedlings from a government program 20 and 30 years before. The trees had been producing, but the government had never come back with further instructions. So the villagers had proceeded with their usual coffee handling methods, developed on the Robusta harvested more commonly here: clean-stripping the branches at harvest, using a basic method of wet hulling via tarps on the ground, and selling the parchment at the local markets for the rock-bottom price. Some of them even cut down the trees and switched to selling vegetables.


Upon meeting us, they were intrigued by the possibility of getting a better price for their coffee. They already had a farmer’s co-op for all their produce, and the leader of that co-op became the linchpin for gathering the community around a common effort to improve their coffee processing. In that first year, 13 growers were interested in working with us.  We spent months teaching farmers how to create specialty Arabica, from the picking to the processing.


We paid higher than the local market rate the farmers would have received for commodity coffee.  Talk about microlots! We logged Mr. Mahmudi’s 18 kilos along with Mrs. Ngatini’s 11 kilos so we could track the quality and moisture levels of each, and give them quality feedback individually. With such small quantities, we initially only sold their coffee roasted locally. As a sort of seed offering, we set aside all the profits of those first year’s sales to be used to invest in upgrading their setup in following years.


They had tasted their own coffee, but only dark-roasted and sugared in the traditional Robusta way. We had memorable times of roasting their coffee and bringing it back for them to drink as it should be enjoyed for the first time.


At first they intended to produce with full-wash methods, but there wasn’t enough water in the village to support that. So they did wet hulling Sumatra-style instead, which was successful. However, one time their wet hulled stock ran out and they brought us some of the natural-processed coffee they had reverted to in their free time. It wasn’t at top quality yet but there was something so unique and special in the flavor that we asked them to ditch the other methods and keep giving us more of the natural.
It wasn’t always smooth sailing as we held the line on quality. One farmer was very disappointed that we wouldn’t buy his coffee. (It was moldy, with bugs in it.) However, he understood the reasons why. The next year, he made sure his quality was high. He knew his effort wouldn’t be wasted because he was guaranteed a good sale price with us, and we were delighted to buy it.

This year’s harvest

Fast forward to 2020 and this village is reaping the fruits of their labor as production accelerates.

Suddenly this year we heard about a village called “Lower Tosoro” which wanted to be part of the action. (We were in Upper Tosoro all the time? Who knew?) Now 50 farmers are part of the co-op – both men and women, about 85% of the homes in this village. They still each do their own picking and hand-processing, so it is no small feat of cooperation that they are able to create an origin with a consistent quality!

They have brand new drying beds purchased with the seed money from those first year of profits that came back to them. They are up to a production quantity of nearly 2 tons. And while they still handle the harvesting and wet-processing stages, they were one of the core origins whose dry processing we finished at our brand new dry mill. (Was the Covid-19 year really the best year to start something new? Turns out, yes.)

For the future, we’re encouraging them to nurture health of their trees. Technically coffee in Tosoro Village is 100% organic (although not certified) – the trees have been neglected and in fact, the farmers do not use any inputs on them. We are currently emphasizing to them steps like pruning, composting, and using natural methods of pest control to achieve optimal harvests.

Our Merbabu Project began with the long term in mind, but after three years we have already seen great results. As more farmers in the area adopt these agricultural practices, more families will reap a better life through coffee. We are pleased to be able to share the results of their labor with you.

Recent Instagram Posts On Merbabu Coffee

Our Agents Of Change at Merbabu in Central Java watching the documentary about becoming Agents Of Change with @mikaeljasin. There's probability a New Age word that describes this but I don't know it.

#caturcoffeecompany #sosogoodcoffeecompany #merbabu #kopijateng #coffeeispeople

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Coming Soon to America: Central Java Mount Merbabu Natural Process.

#Merbabu #centraljavacoffee #kopijateng #indonesiaspecialtycoffee #indonesia #coffeeprocessing

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"Hello everyone, I am Pak Jaimin. We here on Mount Merbabu have been working hard with Bright Java to bring you great beans. Please by my coffee."

#Merbabu #kopijateng #coffeeprocessing #coffeeispeople #farmerdirect #specialitycoffee

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Really pleased with the sortation results from our sized Grader and gravity separator. While still needing a final hand sort on this, our #Merbabu natural process it will be a much shorter process and we should have the first 500kg of the 2020 harvest ready by the end of the week. Order up!

#kopiMerbabu #kopiindonesia #coffeeprocessing #specialitycoffee #coffeeexporters #drymill

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Let's make some naturals.

#kopiindonesia #specialtycoffee #indonesiaspecialtycoffee #merbabu

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If you could only smell the goodness in these dried coffee cherries.

#naturalprocess #Merbabu #kopiindonesia #centraljavacoffee #coffeehunter #coffeeispeople

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Cherry selection is one of the most important factors in green coffee quality. Too ripe and you end up with rotted fruit flavors in your coffee. Too green abs you will have bitter, astringent notes. Here one of our #Merbabu farmers shows off fresh picked cherries as good as it gets from that origin.

#kopiindonesia #specialtycoffee #indonesiaspecialtycoffee #arabicaMerbabu #coffeehunter #coffeeispeople

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Some of our best coffee has come from our nearby Mt. Merbabu.

Beberapa kopi terbaik kami datang dari Gunung Merbabu.
#indonesia #coffee #specialtycoffee #coffeehunter #Merbabu

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The harvest is still coming! We recently purchased netting for our farmers in #Merbabu who make an awesome natural processed coffee. With this netting we will have them build raised parapets for more efficient drying. DM to find out how to get on the list to receive some of our Natural Process Merabu when then harvest is complete.


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The harvest is coming! Here @handoko100 is instructing our co-op partners in building parapets to dry natural picked coffee cherries. DM to find out more about this coffee.


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At the beginning of 2020, Mount Merbabu had become one of our signature origins for natural processing. For a catimor variety, this coffee has a relatively high sugar content at about twenty to twenty-two percent, and we love its nutty sweetness and the heavy body characteristic of many Indonesian coffees. When we heard about the chance to use a new processing method to improve the flavor, we knew the village of Tosoro would be a great candidate.

Mikael Jasin, Indonesia Barista Champion ’18 and ’19 and 4th in World Barista ’19, along with Indonesia International Trading Company, partnered with us to introduce Tosoro to a processing method relatively new to the world of coffee: anaerobic fermentation. Dr. Intan Taufik, a microbiologist at the Bandung Institute of Technology, also joined the team to study Mount Merbabu’s terrior – the unique environmental factors that influence the coffee’s flavor – and help us develop our starter. We used a terrior-specific microbial mix, called a starter, to impart specific flavors to the green coffee beans.

Anaerobic fermentation works by limiting oxygen flow (our farmers use sealed plastic bags) and allowing only certain microbes to develop and ferment throughout the process. By controlling the microbial population and adding specific microbes through a starter, we limit bacteria that cause subpar flavors and lead to quicker spoilage of the green beans. In this environment, fructose breaks down into alcohol acids that enhance the coffee’s taste. Anaerobic fermentation is popular for its development of complex flavors. As we started our experiment with anaerobic fermenting for the first time, we received some unexpected results. 

After picking the ripe coffee cherries, we were ready to begin the anaerobic portion of the process, but the microbe starter had not yet arrived from the university. Our farmer relations manager was worried that the coffee would spoil, so he went ahead and started the anaerobic process without using any additional starters – the fermentation occurred with all-native bacteria and yeast from the local soil. Once it all came to the cupping table in steaming mugs, that self-started fermentation batch turned out to be the best of all. Dr. Intan Taufik even traveled out here to take soil samples and research the nature of this special terroir. The success of this process reminded our team about the interrelatedness and interdependence of the land, the plants, and the people. That beautiful connection truly influences the quality of your cup of coffee.

In the end, we pulled out unique flavors we had never tasted before in Mount Merbabu’s beans, like ambarella, grape skins, and nectarine. The Merbabu coffee’s quality score (SCAA) went from a basic 81-83 to an 85, making it a specialty coffee. The flavor profile developed by anaerobic fermentation is increasingly hyped, and for good reason. We are excited to continue to develop this process, expand it to more of our villages, and further improve the flavor for next year’s harvest.

On the nearby Mt. Merbabu, our farmers are harvesting their coffee. One of our employees, Eko, is working alongside them and showing them better ways to pick and process their coffee.


They are using refractometers to measure the sugar content of cherries and pick the best ones.


Using Bright Java investments, they have built raised drying beds for better processing. Eko has been teaching them about the prime temperature to keep drying beds at: between 25 and 32 degrees Celcius

Central Java is not an internationally known coffee origin right now, but the truth is that delicious coffee grows on several mountains here, including in a village on Mt. Merbabu only 30 minutes away from our office. We are finding that we have the special privilege to assist some of these small regions to develop their capacity and quality up to international levels.

We first got to know this village last year when our team met with Pak Kertoredjo in Tosoro Village. At that time we tried coffee processed by his family and were delighted by the quality.

Starting early this year, we’ve been meeting, talking, and drinking coffee with other residents as well exchanging ideas and knowledge. On average all heads of households have coffee trees, but just a few each. Most of them have never drunk their own coffee. One day we bought coffee beans from them, roasted them, and returned it to them to try!

Starting early this year, we’ve been meeting, talking, and drinking coffee with other residents as well exchanging ideas and knowledge. On average all heads of households have coffee trees, but just a few each. Most of them have never drunk their own coffee. One day we bought coffee beans from them, roasted them, and returned it to them to try!

At present there are 13 residents who are interested in collaborating in the post-harvest process and selling coffee with us. Merbabu coffee is manually pulped, wet-milled, with a dry and honey process. This year it was truly microlot coffee – we labeled each bag with each household farmer’s name. At this stage each farmer is at a different level of quality so we can’t combine it into one origin until they reach greater consistency of quality.

For the roasting and display stage we collaborate with a local coffee shop, Aromia & Wijaya Roastery Salatiga. As a special development project, we are setting aside the sales profits from this village to invest back into it and help them establish a farmer co-op with processing equipment, such as a manual pulper and huller. We’ll see where this opportunity leads! Our goal is to give the farmers education and opportunity but the initiative must be theirs.





Located less than 15km uphill from our office here in Central Java, this area holds a special place in our hearts and we have been dedicated to investing in these small lot holders and their village ever since we met. More than coffee the relationships being built here have deeply impacted us; we learn daily so much from these humble, loving people and their culture. 

Continue reading “In our Backyard on Mt. Merbabu”