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Cape Town – Ever wondered what makes some cups of honey-bush tea bitter and others not?

This is the question a Stellenbosch PhD student Lara Alexander aimed to answer when investigating phenolic compounds in both “unfermented” (green) and fermented honey-bush tea.

“Bitterness is not acceptable in honey-bush tea, known and marketed for its characteristic and pleasant sweet taste. Some batches of Cyclopia genistoides have a bitter taste profile.

“This species is one of the Cyclopia species currently cultivated for the production of honey-bush tea. Bitterness is even more prominent in the unfermented herbal tea.”

Alexander has been working on honey-bush tea under the mentorship of professor Lizette Joubert (her supervisor) since 2013.

In her research, Alexander considered the effect of fermentation on bitter intensity and the content of hot water infusions. 

Both species studied (C. genistoides and C. longifolia) contain high levels of xanthone and benzophenone, and have been found to produce bitter infusions, she pointed out. The two species differed in terms of bitter taste, phenolic content and response to fermentation.

“The results indicated that the benzophenone-rich tea fraction was not bitter, the flavanone-rich fraction was somewhat bitter, and the xanthone-rich fraction was distinctly bitter. 

"Bitter-taste reduction through fermentation was more effective for C. longifolia than for C. genistoides, highlighting the problem the industry faces with inconsistent production batches.”

Currently, demand for honey-bush tea far outstrips supply. Most of the honey bush (about 80%) is wild-harvested and the rest is cultivated.