the Science of Taste and Flavor

August 8, 2012 in Teas by Mike

Chas, from ATMA,  sent this article regarding the science of taste and flavor:

This was an interesting analysis and good food for thought. It is very detailed, with valid scientific facts. My criticism would be that while I agree that the concept of taste is complex, I don’t agree that it is necessary to make Tea Tasting really this complicated? I guess for some, this analysis is useful, but for me, the sensory evaluation of Tea is more simple and enjoyable and not so cerebral.

Flavor is a combination of two sensory perceptions: taste and smell. These, like the other senses, are mostly subjective. They are subject to our idiosyncratic ‘likes’ and ‘dislikes’. We can certainly re-train our tastes. For example, I used to like Earl Gray Tea but now that I understand Tea, I find Bergamot to be overpowering, masking the more subtle flavors and aroma’s of tea which I now prefer. The reality still is that taste is 90% subjective.

Like the article states, the more objective aspects of taste are salt, sweet, sour, bitter, astringent (which the author lists as a “mouth-feel), (and metallic). I think that it is useful to know what parts of the tongue has the specific receptors that transmit these qualities to the brain, but even anatomy varies from person to person: “These taste buds are generally located in very specific areas on the tongue (sweet in front, salt next and along the sides, acid (sour) next and along the sides, bitter in the rear and from side to side covering the back of the tongue). However, all types of taste buds can be found located sparsely throughout the tongue’s entire surface.”

It is in the balance of these combined ‘taste’ qualities and how they combine with our sense of smell, where the subjectivity comes into play.  We might think that the taste is too sour, not sour enough, too bitter, not bitter enough, too astringent etc.. It is what we prefer not what is necessarily objectively true. Smell is even more complex, but also more subjective. I think that we all agree that how much a Tea appeals to us is based on the how much we like the combination of the smell and the taste that we get from it.

I particularly enjoy trying to describe the various ‘notes’ of flavor. The base note may be malt or caramel, yet it may also possess various, more subtle, notes of other flavors, fruity or floral. When all of these notes work together for me, and the finish is not bitter, or metallic,  then I say that the Tea is good.

I believe that tea qualities are dependent on: 1) How the tea was processed, and also the humidity and temperature conditions when it was processed, 2) the soil conditions (ph, mineral content, micro-organisms, etc) where the Tea was grown. 3) The temperature, humidity, amount of rain, sunlight-shade, etc. (the Climate) that the plants received just prior to it being picked, 4) What soil amendments, fertilizers and farm chemicals are used, 5) How the tea is picked and how much of the growing tip, the Pecko, is picked, 6) The actual varietal, cultivar, or blend of cultivars grown can also affect the qualities of the tea.

Elevation can also be a factor because of the difference, in general, in the temperature, rainfall and amount of sunlight that exist in various elevations. Higher elevation does not necessarily mean higher quality.  In general, at higher elevations, there are cooler temperatures, more rain and more overcast. In many countries where tea is grown, low elevation means very hot, in excess of 95 degrees during the day and/ or constantly sunny days. These are not the best conditions for producing a complex flavorful tea because too much sun and too-high temperatures can bring out unbalanced high astringency and bitterness, especially in the green and oolong teas. However, in Hawaii, in addition to having rich volcanic soil,  there are many low-elevation micro-climates, like Onomea, which have long overcast period, cool breezes and temperatures rarely over 82 degrees. We have demonstrated that we can produce teas that compare to ‘high-quality’ teas grown at the higher elevations. The final test is in the flavor of the tea produced and we have received an abundance of very positive agreement regarding the exceptional complex flavors in Onomea Teas.