Soka - The Full Picture

Soka - The Full Picture

SOKA is looking back to go forward.

At Empirical, the creative process takes various forms. We may fall in love with an ingredient and explore all its different layers, or feel inspired by a process and experiment with it. And there are avenues we take when we want to deeply immerse ourselves in research projects; we go down a myriad of paths to find something new. This time, it led us to SOKA, where we examined sorghum as a crop that truly connected us to the flavors of the landscape. 

Exploring Sorghum

We have always sought different sources of saccharides, necessary for the fermentation process; what flavors they can bring, and what starting point they can become. From beet molasses to different starchy experiments, we found ourselves looking at Sorghum. 

First domesticated in Africa thousands of years ago, Sorghum made its way across the globe to now be the 5th most-produced cereal crop globally. Its regenerative and drought-resistant properties make it a very versatile and sustainable crop to grow, able to adapt to many climates. Whereas its grains have mostly been used for food, feed, replanting, and biofuel production, the sugarful stalks are often looked over.

As we delved further into the history, properties, and high sugar content of sorghum we saw that the seeds have been used in the local production of alcohol in Africa and Asia but encountered very few made of the cane. The stalks of sweet sorghum are widely underutilized and the tradition of juicing them has slowly faded away. 

Fresh sorghum juice lends very green springy flavors of melon, cucumber and green apple. The syrup on the other hand has darker aromas of fall with notes of hay and toasted honey. We had to make something with this amazing crop.

The Copenhagen Tasting Phase

So we started testing it in Copenhagen, beginning with fermenting the syrup. We also wanted to experiment with fresh juice. We quickly realized that European countries mostly grow sorghum varieties for their seeds and not for sugar production. Yunus, our sourcing magician, set himself on a mission to procure fresh stalks. He finally got in touch with Danny Ray Townsend in Kentucky, who, through his network, connected us with a producer of sweet sorghum in the Netherlands. 

We got a bunch of stalks from him and started the process of juicing. The seeds were saved and replanted in Bornholm for future experiments. The very green flavor profile of the juice, with singular melon and apple notes, is very hard to attain in spirits outside of the Caribbean islands. After playing with different strains of yeast from White Labs, we picked Thai Rice Chong. This particular strain of yeast heightened the fruity aromas of the juice while bringing out the hay undertones of the syrup. We were hooked and needed more.

The Wisconsin Move

Meet Richard and Brenda Wittgreve from Rolling Meadows, Elkhart Lake, Wisconsin. 

Although mostly grown in the Southern States, sorghum is also at home in the Wisconsin landscape, with a more humid continental climate.

The Process

We ferment both fresh sorghum cane juice and sorghum syrup from Richard and Brenda for our blend. 

The Juice

Like most sorghum producers, Richard built his own equipment for the growing and processing of the cane. 

When the crop is ready, Richard jumps on his Mad Max-like vehicle consisting of a three-row harvester at the front, a press in the middle custom-built from a concrete cement truck to juice the stalks while being harvested. The bright green juice is filtered through an automatic scraper and pumped into a tank at the back of the machine, preserving the freshness and sorrel-like flavors of the cane.

The Syrup

The filtered juice is heated with natural gas steam in a home-built 5-meter-long pan. The impurities and protein forming at the top of the liquid during the reduction are skimmed before transferring the liquid to another pan where the different temperatures can be better controlled. The result is a deep brown syrup.


Sorghum juice needs to be processed very quickly to avoid any undesired contamination. Once the pressing is done, we take an hour's drive to Milwaukee where we bring it to Central Standard Distillery. We ferment our juice for three days at room temperature (23-24° Celsius) resulting in an 8/9% ABV wash.

We had experimented with dunder in the past when working with molasses, inspired by the fermentation methods used in Jamaican distilleries. In SOKA; we reuse the leftover wash from the distillation of our fermented juice, to ferment our syrup before distilling it. This process concentrates critical esters and contributes notes of fermented grass and a touch of brininess


We want to preserve all the beautiful esters created in the fermentation process and maintain the silage undertones of the juice. Vacuum distillation is the solution. Since our equipment is located in Copenhagen, we had to look for an alternative. We found the prototype of a piece of equipment used for the removal of alcohol in beer and wine. We examined it and realized that with some tweaking with the technician,  the technology could be turned into a vacuum still at the Central Standard Distillery. Problem solved.

Once distilled, we blend our syrup (50%) and fermented juice (50%) cuts to become the fully formed SOKA.

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