The Tea Research Institute (TRI) was established in July 2013 following the operationalization of KALR Act of 2013 that formed the Kenya Agricultural and Livestock Research Organization (KALRO), a premier national research organization, which brought together the former Tea Research Foundation of Kenya (TRFK), Kenya Agricultural Research Institute (KARI), Kenya Sugar Research Foundation (KESREF) and Coffee Research Foundation (CRF). Tea Research Institute (TRI) is one of the sixteen research institutes created under KALRO but its mandate "to promote research and investigate problems related to tea and such other crops and systems of husbandry as are associated with tea throughout Kenya including the productivity (yield), quality and suitability of land in relation to tea planting; and matters ancillary thereto" remaining the same. It is worth noting that The Tea Research Foundation of Kenya (TRFK) had been established in 1980 to replace the former Tea Research Institute of East Africa (TRIEA) following the breakup of the East African Community.

Research focuses therefore on development of improved cultivars, suitable technologies for improvement of yield (quantity of green tea leaf/made tea per hectare) and quality of diversified tea products.

This is done through development of appropriate practices for tea production including breeding, clonal selection, correct plant nutrition, optimal crop husbandry methods, crop physiological studies, control of major pests and diseases, tea manufacture, marketing and utilization of finished products.

The annual tea production in Kenya has consistently increased from 1963 to date. It is expected that production will exceed 500,000 metric tons made tea (mt) by the year 2020. Up to 60% of the total Kenyan tea crop is produced by the smallholder sub-sector. This subsector has been expanding rapidly as a consequence of expansion of the hectarage under tea, and adoption of improved cultivars that have a high productivity per unit area. Overall, Kenya has recorded the highest average yields per unit area in the world.

The success of the Kenyan tea industry has among other factors, been ascribed to deployment and leveraging of appropriate research and development (R&D) outputs in the production value chain. The R&D outputs have largely been developed by the Tea Research Institute (TRI).   For example, Tea Research Institute has developed and disseminated improved tea cultivars that have increased tea yields in Kenya from an average of 1,500 kg to 3,300 kg of made tea per hectare per year (mt/ha/yr) on the large estates, and from an average of 600 kg to 2,300 kg mt/ha/yr under the smallholder production system. Significant yield increases and improved tea quality have been achieved through the development and commercialization of improved tea cultivars and production technologies. 

Over time, the Institute has developed over 1000 improved cultivars, out of which 53 cultivars have been selected for consistent superiority in yield and quality and released for commercial exploitation by both smallholder and large estate growers.  Seventeen of these cultivars are capable of yielding between 5,000 kg and 8,000 kg of made tea per hectare per year.  These yield levels are some of the highest in the world and are in magnitude of three times the average yields of unimproved tea varieties.

Currently the tea industry in Kenya is facing both local and global challenges ranging from prohibitive production costs, minimal value addition to lack of product variations and climate change. The Tea Research Institute is aligning its research to tackle these emerging challenges.

Tea Research Institute has reoriented its research agenda to focus more on tea products diversification and value addition. TRI has developed and released a new tea cultivar (‘’Purple tea’’) that is rich in a pigment called anthocyanin, which is widely used for the manufacturing of fast moving consumer goods such as soaps, shampoo and detergents. Research is also assessing the potential health benefits of tea as they have anti-inflammatory and anti-parasite properties and may be used to protect the liver from damage.

Towards addressing issues on climate change and to enable the tea industry to survive the expected negative impacts, Tea Research Institute is developing new technologies to mitigate the adverse effects, including environmental conservation efforts and development of new tea climate change compatible cultivars.

The Institute is responsible to the Agricultural and Livestock Research Organization (KALRO) which is under the Ministry of Agriculture, Livestock and Fisheries (MoALF).  The KALRO Board of Directors in conjunction with the parent ministry is mandated to formulate policies and guidelines for the proper and effective operation of the Institute.