The Complete Guide to Oolong Tea Craftsmanship: Distilling the Art and Science of Flavor Formation

Grab the popcorn! Our new Youtube video follows the six steps of Oolong tea craftsmanship, exploring flavor formation through a scientific lens, and through the eyes of Wu Mountain friend and mentor, Ajin, an Oolong Tea Master making great tea in China’s Southern Guangdong Province.

The video cites a total of 52 peer-reviewed scientific articles, with citations appearing in the upper-right corner throughout the video. Below the embedded video in this post we’ve provided the complete Works Cited, so you can search the titles and follow up with more learning on your own. Enjoy!

Works Cited:

1.         Zeng, L., et al., Chinese oolong tea: An aromatic beverage produced under multiple stresses. Trends in Food Science & Technology, 2020. 106: p. 242-253.

2.         Xu, Y.Q., et al., Quality development and main chemical components of Tieguanyin oolong teas processed from different parts of fresh shoots. Food Chemistry, 2018. 249: p. 176-183.

3.         Zeng, L.T., et al., Does oolong tea (Camellia sinensis) made from a combination of leaf and stem smell more aromatic than leaf-only tea? Contribution of the stem to oolong tea aroma. Food Chemistry, 2017. 237: p. 488-498.

4.         Sharma, E., R. Joshi, and A. Gulati, l-Theanine: An astounding sui generis integrant in tea. Food Chemistry, 2018. 242: p. 601-610.

5.         Zhang, L., et al., Association between chemistry and taste of tea: A review. Trends in Food Science & Technology, 2020. 101: p. 139-149.

6.         Pandey, P., V. Ramegowda, and M. Senthil-Kumar, Shared and unique responses of plants to multiple individual stresses and stress combinations: physiological and molecular mechanisms. Frontiers in Plant Science, 2015. 6.

7.         Frodl, T. and V. O’Keane, How does the brain deal with cumulative stress? A review with focus on developmental stress, HPA axis function and hippocampal structure in humans. Neurobiology of Disease, 2013. 52: p. 24-37.

8.         Lu, Y., et al., Responses of electrical properties of tea leaves to low-temperature stress. International Journal of Agricultural and Biological Engineering, 2015. 8(5): p. 170-175.

9.         Zhou, Y., et al., Formation of (E)-nerolidol in tea (Camellia sinensis) leaves exposed to multiple stresses during tea manufacturing. Food Chemistry, 2017. 231: p. 78-86.

10.       Atkinson, N.J. and P.E. Urwin, The interaction of plant biotic and abiotic stresses: from genes to the field. Journal of Experimental Botany, 2012. 63(10): p. 3523-3543.

11.       Mithoefer, A. and W. Boland, Plant Defense Against Herbivores: Chemical Aspects, in Annual Review of Plant Biology, Vol 63, S.S. Merchant, Editor. 2012. p. 431-450.

12.       Zhou, F. and E. Pichersky, More is better: the diversity of terpene metabolism in plants. Current Opinion in Plant Biology, 2020. 55: p. 1-10.

13.       Murphy, K.M. and P. Zerbe, Specialized diterpenoid metabolism in monocot crops: Biosynthesis and chemical diversity. Phytochemistry, 2020. 172: p. 112289.

14.       Zeng, L., N. Watanabe, and Z. Yang, Understanding the biosyntheses and stress response mechanisms of aroma compounds in tea (Camellia sinensis) to safely and effectively improve tea aroma. Critical Reviews in Food Science and Nutrition, 2019. 59(14): p. 2321-2334.

15.       Hu, C.-J., et al., Formation mechanism of the oolong tea characteristic aroma during bruising and withering treatment. Food Chemistry, 2018. 269: p. 202-211.

16.       Wang, Y., et al., Novel insight into the role of withering process in characteristic flavor formation of teas using transcriptome analysis and metabolite profiling. Food Chemistry, 2019. 272: p. 313-322.

17.       Yang, Z., S. Baldermann, and N. Watanabe, Recent studies of the volatile compounds in tea. Food Research International, 2013. 53(2): p. 585-599.

18.       Fu, X., et al., Regulation of formation of volatile compounds of tea (Camellia sinensis) leaves by single light wavelength. Sci Rep, 2015. 5: p. 16858.

19.       Hou, Z.-W., et al., Effects of dynamic and static withering technology on volatile and nonvolatile components of Keemun black tea using GC-MS and HPLC combined with chemometrics. LWT, 2020. 130: p. 109547.

20.       Santino, A., et al., Jasmonate signaling in plant development and defense response to multiple (a)biotic stresses. Plant Cell Reports, 2013. 32(7): p. 1085-1098.

21.       Liu, S.C., et al., Transcriptomic Analysis of Tea Plant Responding to Drought Stress and Recovery. Plos One, 2016. 11(1).

22.       Yang, L., et al., Response of Plant Secondary Metabolites to Environmental Factors. Molecules, 2018. 23(4).

23.       Wasternack, C. and M. Strnad, Jasmonates are signals in the biosynthesis of secondary metabolites – Pathways, transcription factors and applied aspects – A brief review. New Biotechnology, 2019. 48: p. 1-11.

24.       Cho, J.Y., et al., Chemical profiling and gene expression profiling during the manufacturing process of Taiwan oolong tea “oriental beauty”. Bioscience Biotechnology and Biochemistry, 2007. 71(6): p. 1476-1486.

25.       Deng, H., et al., Transcriptome analysis reveals the effect of short-term sunlight on aroma metabolism in postharvest leaves of oolong tea(Camellia sinensis). Food Research International, 2020. 137: p. 109347.

26.       Sud, R.G., R. Prasad, and M. Bhargava, EffEct of weather conditions on concentration of calcium, manganese, zinc, copper and iron in green tea (Camellia sinensis (L) O Kuntze) leaves of north-western India. Journal of the Science of Food and Agriculture, 1995. 67(3): p. 341-346.

27.       Lou, W., et al., Impact of climate change on inter-annual variation in tea plant output in Zhejiang, China. International Journal of Climatology, 2020.

28.       Yu, X., et al., Nonvolatile metabolism in postharvest tea (Camellia sinensis L.) leaves: Effects of different withering treatments on nonvolatile metabolites, gene expression levels, and enzyme activity. Food Chemistry, 2020. 327: p. 126992.

29.       Gui, J., et al., Does Enzymatic Hydrolysis of Glycosidically Bound Volatile Compounds Really Contribute to the Formation of Volatile Compounds During the Oolong Tea Manufacturing Process? Journal of Agricultural and Food Chemistry, 2015. 63(31): p. 6905-6914.

30.       Suzuki, T., et al., Tissue distribution and intracellular localization of catechins in tea leaves. Bioscience Biotechnology and Biochemistry, 2003. 67(12): p. 2683-2686.

31.       Wang, Y., et al., Impact of Six Typical Processing Methods on the Chemical Composition of Tea Leaves Using a Single Camellia sinensis Cultivar, Longjing 43. Journal of agricultural and food chemistry, 2018.

32.       Guo, X.-Y., et al., Polyphenol oxidase dominates the conversions of flavonol glycosides in tea leaves. Food Chemistry, 2021. 339: p. 128088.

33.       Jolvis Pou, K.R., Fermentation: The Key Step in the Processing of Black Tea. Journal of Biosystems Engineering, 2016. 41(2): p. 85-92.

34.       Tanaka, T. and I. Kouno, Oxidation of tea catechins: Chemical structures and reaction mechanism. Food Science and Technology Research, 2003. 9(2): p. 128-133.

35.       Menet, M.C., et al., Analysis of theaflavins and thearubigins from black tea extract by MALDI-TOF mass spectrometry. Journal of Agricultural and Food Chemistry, 2004. 52(9): p. 2455-2461.

36.       Hirose, S., K. Tomatsu, and E. Yanase, Isolation of key intermediates during formation of oolongtheanins. Tetrahedron Letters, 2013. 54(51): p. 7040-7043.

37.       Ma, C., et al., Study of the aroma formation and transformation during the manufacturing process of oolong tea by solid-phase micro-extraction and gas chromatography–mass spectrometry combined with chemometrics. Food Research International, 2018. 108: p. 413-422.

38.       Ravichandran, R. and R. Parthiban, The impact of processing techniques on tea volatiles. Food Chemistry, 1998. 62(3): p. 347-353.

39.       Lin, S.Y., et al., Effect of shaking process on correlations between catechins and volatiles in oolong tea. Journal of Food and Drug Analysis, 2016. 24(3): p. 500-507.

40.       Wu, L., et al., Understanding the formation mechanism of oolong tea characteristic non-volatile chemical constitutes during manufacturing processes by using integrated widely-targeted metabolome and DIA proteome analysis. Food Chemistry, 2020. 310: p. 125941.

41.       Zeng, L.T., et al., Formation of Volatile Tea Constituent Indole During the Oolong Tea Manufacturing Process. Journal of Agricultural and Food Chemistry, 2016. 64(24): p. 5011-5019.

42.       Donlao, N. and Y. Ogawa, The influence of processing conditions on catechin, caffeine and chlorophyll contents of green tea (Camelia sinensis) leaves and infusions. LWT, 2019. 116: p. 108567.

43.       Wang, H., et al., Influence of fixation methods on the chestnut-like aroma of green tea and dynamics of key aroma substances. Food Research International, 2020. 136: p. 109479.

44.       Sharma, V., A. Gulati, and S.D. Ravindranath, Extractability of tea catechins as a function of manufacture procedure and temperature of infusion. Food Chemistry, 2005. 93(1): p. 141-148.

45.       Perez-Burillo, S., et al., Effect of brewing time and temperature on antioxidant capacity and phenols of white tea: Relationship with sensory properties. Food Chemistry, 2018. 248: p. 111-118.

46.       Fu, Y.-Q., et al., Effect of baking on the flavor stability of green tea beverages. Food Chemistry, 2020. 331: p. 127258.

47.       Ames, J.M., Control of the Maillard reaction in food systems. Trends in Food Science & Technology, 1990. 1: p. 150-154.

48.       Guo, X., et al., Contribution of l-theanine to the formation of 2,5-dimethylpyrazine, a key roasted peanutty flavor in Oolong tea during manufacturing processes. Food Chemistry, 2018. 263: p. 18-28.

49.       Feng, Z.H., et al., Tea aroma formation from six model manufacturing processes. Food Chemistry, 2019. 285: p. 347-354.

50.       Qu, F., et al., Effect of different drying methods on the sensory quality and chemical components of black tea. LWT, 2019. 99: p. 112-118.

51.       Babu, A.K., et al., Review of leaf drying: Mechanism and influencing parameters, drying methods, nutrient preservation, and mathematical models. Renewable and Sustainable Energy Reviews, 2018. 90: p. 536-556.

52.       Guo, X., et al., Changes of volatile compounds and odor profiles in Wuyi rock tea during processing. Food Chemistry, 2021. 341: p. 128230.