Recent projects have called upon me to dig into the research of tasting tea, both as a process of perception within the mind/body, but also the most commonly used practices of professional tea tasters in evaluating teas.
As I proceed, I am becoming convinced that many tea professionals are pushing the flavor aspect of tea tasting to the detriment of other, potentially more rewarding elements of tea. As an overall strategy, this confines the professionals’ and end consumers’ abilities to recognize and appreciate quality teas.
One of the first stops on my journey was the work of Dr. Utermohlen and her work on tea, taste, and science. She has made significant strides in increasing the tea community’s awareness of:
a. How the words taste and flavor are defined and used
b. The geography of taste
c. Taste sensitivity and age
d. Her research also points toward a new and better direction – people appreciate teas for more than the flavor or taste
These and other findings point out potential weaknesses of current, commonly used tasting practices. When professional cuppers evaluate the taste of tea liquor, they usually employ the slurp method. The goal of the slurp method, as is often described, is to suck a teaspoon of liquor into the mouth with such force that it vaporizes the tea and allows its aromas to be tasted.
The science and mechanics behind the slurp tell more of the story. The slurp is largely a method for facilitating retronasal smelling. That is, aroma particles travel up into the nasal cavity via the back of the mouth. Instead of sniffing by taking air in through the nostrils, retronasal smelling is facilitated as air moves from the back of the mouth, up into the nasal cavity, and then out of the nose during exhalation.
While repeated studies have have shown retronasal smelling does allow for the perception of aroma and flavor, the slurp method is not as straightforward as it may appear.
There are some obstacles of perception related to retronasal smelling, and therefore to the slurp technique:
1. Retronasal smelling intensity and breadth is likely affected by mouth movements (Burdach and Doty), (Halpern 2004). I have not yet found sufficient data explaining that slurping offers a superior retronasal smelling experience compared to swirling tea in the mouth in the areas of smell/flavor intensity and breadth (i.e. range) of smells/flavors detected.
2. Retronasal smelling tends to yield better results before swallowing, and during exhalation. Slurping is not as straightforward as it may seem. Getting a superior benefit from slurping will depend on a) how well the tea becomes vaporized, b) how much aromatic compound/vapor you can get to travel into your nasal cavity while exhaling but before swallowing.
So why do so many tea tasters stand by the slurping method? My suspicions are:
1. They taste tea samples in such great volume, that they believe slurping is a quick, sufficient experience for evaluating one tea over another.
2. They are less informed of the research on the mechanics and limitations of retronasal smelling via slurping.
3. They are less attuned to appreciating the other desired qualities of tea
4. They feel pressured to conform to accepted practices of the professional tea tasters’ community.
4. Given the power of smells on the brain’s memory and other aspects, it is simply easier to train themselves and others to recognize and appreciate smell.
The fundamental problem with the professional tea tasting process is that it is mostly a smell-based activity. Additionally, the slurp technique fails to reveal the dynamic components and character of tea taste.
A tea’s taste can alter when in the mouth, allowing for different flavors or sensations as the tea moves from front to back. A sip of tea can express roasted notes one moment in the mouth, or fruity components the next moment, then astringent character the next. And these components can vary with the temperature of the tea.
Looking back at Dr. Utermohlen’s research conducted on World Tea Expo attendees, smell/aroma/taste were not always the only, or even necessarily the main reason for their liking of a tea. It is possible that aftertaste, texture, or similar components are a driving reason for liking a tea. If so, this opens the door to new inquiry There is a possibility that texture or aftertaste may even be driving reasons for the liking of a tea. They may even form the dominant components of a tea’s taste “gestalt,” and that vocabulary gets in the way. In such cases, people may be using the words “taste,” or “flavor” to say why they like a tea, when what they precisely mean are aftertaste, or texture, or something else. Their brains may be combining several sensations into one “taste” experience they have not consciously unravelled, but does not consist mainly of retronasal smelling.
If tea taste gestalt does not consist only, or evenly mainly of smell/aroma, evaluating tea by slurping fails.
1. Slurping 1 teaspoon (approximately 4 – 5 mL) of tea fails to express the potential acidity of a tea. Research has shown that saliva levels in the mouth can neutralize the acidity of 4mL of liquid (Christensen 1987). Inasmuch as acidity and pH affect texture and astringency of tea, slurping cannot create the equivalent mouthfeel/texture experience of a sip (e.g. 10 – 15 mL).
2. Coffee evaluators have known of the drawbacks of slurping for some time, and some of their leading professionals have advocated a sip-and-spit method.
Research I have discovered/used so far:
Espresso Coffee: The Science Of Quality via Google Books. This work references Christensen above.
Burdach and Doty, 1987. The Effects of Mouth Movements, Swallowing, and Spitting on Retronasal Odor Perception.
Walker Tea Review- a tea blog with tea reviews and tea tastings.
Want to see a tea reviewed? Contact me: firstname.lastname@example.org