From lab to market University of Nairobi goes into winemaking

The University of Nairobi (UoN) joins Jomo Kenyatta University University in winemaking, as it seeks to sway allegiance to locally produced alcoholic beverages.

Unlike traditional wines made from grapes or berries, UoN uses exotic fruits, which offer unique flavours that showcase Kenya’s rich biodiversity.

Led by Dr George Ooko and Dr Duke Gekonge, the initiative focuses on small-scale processing techniques with added value.

“This began as a mango production hub to model for farmers, and then we started a project with Duke during his PhD,” Dr Ooko told the BDLife.

This approach not only diversifies the wine industry but also highlights the university’s commitment to sustainable, locally-sourced ingredients.

At the university, the journey of wine production begins with the careful selection of fruits. The guavas are sourced from Taita Taveta, cacti from Laikipia, Baringo, and Kajiado, and mangoes from the Ukambani.

This selection process is crucial as the quality of the fruits directly impacts the final product. The university collaborates with local farmers, providing them with the necessary knowledge and resources to cultivate fruits that meet the required standards.

“For cactus, we go for the red prickly pears, both white and red types. For mangoes, we prefer the apple varieties because of their sugar quality. For guavas, we use the red ones more than the white,” Dr Gekonge said.

The timing of the harvest is meticulously planned to ensure the fruits are picked at their peak, essential for achieving the desired balance of sugars, acids, and tannins in the wine.

“We buy farm-ripe fruits that have attained optimal maturity. We then sort them, leaving out the overly ripe ones, and extract the pulp. Well-matured fruits yield over 70 percent pulp. After sorting and pulping, we use the pulp for wine processing,” he said.

Once the fruits are harvested, they are taken to the university’s advanced fermentation facility. The first step is crushing and destemming, where the fruits are separated from their stems and gently crushed to release their juice.

Yeast is added to the juice to start fermentation, converting sugars into alcohol and carbon dioxide. The fermentation process is closely monitored to ensure it goes smoothly and achieves the desired flavour. Temperature control is crucial during this stage as it affects the fermentation rate and flavour development.

“You can use any equipment for fermentation as long as it is sealed properly to create anaerobic conditions. We use micro fermenters, which hold up to 100 litres and maintain anaerobic conditions, meaning no oxygen is present. Yeast digests sugar in these conditions. We balance the fruit and water ratio and adjust sugar and acid levels to optimise fermentation. Tropical fruits are often very acidic and low in sugar, so we boost sugar and adjust acidity. This setup helps us produce the right alcohol levels and develop sustainable technologies for the future,” Dr Gekonge explained.

After fermentation, the wine is transferred to ageing vessels for maturation. UoN uses stainless steel tanks for ageing wines intended to be fresh and fruity. The process can take from several months to several years, depending on the type of wine. During this time, the wine undergoes chemical changes that enhance its flavour, aroma, and texture.

Dr Gekonge said,“Most wines take about five days for primary fermentation, where sugars are broken down. After that, ageing can start, taking five to 14 days. For us, primary fermentation lasts about a month, and then we age the wine for three to six months before packaging. Ageing continues even after packaging, so we can package the wine today and sell it next year.”

Quality and safety are crucial in wine production. The director explains that in their winemaking class, they learn about amelioration, which involves adjusting the sugar and acid balance to determine alcohol levels. The department has strict quality control measures to ensure the wine meets high standards, including regular testing for alcohol content, acidity, and microbial stability.

“Fruits with high sugar content result in higher alcohol content, while low sugar fruits produce less alcohol. Regulations for table wines require a minimum alcohol content of 8 to 15 percent. We adjust the sugar level, known as the bricks level, in the mixture of fruit, water, and sugar. Higher brick levels lead to higher alcohol content, but too much sugar can shock the yeast, slowing fermentation. We aim for a brick level of 22 to 25 for optimal results,” he said.

Dr Gekonge observed that they buy tonnes of fruits, giving value to previously wasted produce like guavas and mangoes. They buy guavas at Sh40 to Sh50 per kilo. By purchasing from farmers, they create household income and generate revenue for those involved in transportation. The farm employs about 10 men directly and indirectly.

Once the wine is ready, the focus shifts to marketing and commercialisation.

Their biggest headache is competing with South African and other imported wines, which have gained popularity in Kenya. South Africa has been making wines for about 300 years and has the biggest market share in Kenya, followed by Chile, and French wine.

UoN says because they are not highly commercial, production capacity is limited, preventing them from stocking in shops. There is also the regulatory issues. They say for now focus is on creating consumer awareness about tropical wines through digital advertising and direct-to-consumer sales.

“We see a promising trend but need to scale up by acquiring large-scale equipment and facilities. The market looks promising, especially since Kenyans love alcohol. We aim to produce thousands of litres per day or month and possibly export,” he said.

The department is trying to diversify away from just teaching. Nowadays, it also hosts students seeking hands-on industrial production experience.

“About 25 percent of our products come from research,” Dr Gekonge said.