A Matter of Feel

by Lori Way, MS, RD

Ahh, the fiery sting of hot peppers, the refreshing cool of peppermint, the sinus-clearing jolt of horseradish. Without these kinds of sensations, a lot of foods would be pretty dull.  For this third part of my posts about tasting, I’d like to focus on mouth-feel, also known as chemesthesis, which is sensed by the trigeminal nerve.  Chemesthesis encompasses sensations of texture, pain, motion, and temperature.  Here are other examples:

  • The tingly sensation from carbonated beverages
  • The mouth-drying nature of astringent tea
  • The actual temperature of foods
  • The bite from raw onions or garlic
  • The slippery feeling of an oyster

The trigeminal nerve has three branches:  The mandibular branch goes to the lower jaw and tongue; the maxillary branch goes to the upper palate, back of the throat, and nose; and the opthalmic branch goes to the eye.  Many common odor and flavor compounds have trigeminal activity, adding much to the appeal (or lack of appeal) of all kinds of foods and beverages.  Note that other nerves around the body can also sense these types of chemical irritations, which you’ve no doubt noticed if you’ve ever gotten hot pepper juice on your fingers.

In our tasting workshop at the 2011 Tea Expo, we measured our baseline trigeminal activity by using regular peppermint candies.  Each person was given a peppermint Lifesaver™ and was instructed to put it in the mouth but not to open the mouth.  We were asked to rate the strength of the flavor (from “strongest imaginable” to “barely detectable”).  Then we were supposed to crunch down on the mint and again rate the flavor intensity.  If we got a rush of flavor when we crunched on it, we were to rate the rush also.  Then finally we were asked to open our mouths and again rate the intensity of the flavor.  I found myself to be awfully “moderate,” which I thought sounded a bit dull.  I didn’t get much of a rush, and I didn’t find the taste of the mint at the end with the mouth open (when it should be the strongest) to be dreadfully strong, although there was a difference.  So, I suppose with regard to trigeminal activity, I’m in the middle somewhere.  There was one person in the class (of about 50-60 people) who could hardly taste the peppermint at all, and one other who thought it was just overwhelming.

Putting it all together

At the end of our class, in an effort to combine all that we had learned, we got to taste actual tea and record our sensations of taste, smell, and mouth feel.  We were given three different pots of tea to brew, plus two pre-brewed iced teas.  We were not told what the teas were, but we were given brewing instructions, water of the proper temperature, and pre-set timers so everyone would be on the same page.   For each tea, we were asked questions such as:

  • How familiar is it?
  • How intense is the flavor?
  • Describe the aroma as you inhale from the cup.
  • Describe the taste as you aspirate the tea into your mouth.
  • Describe the nerve response of this tea as you savor its liquor.
  • What words come to mind when you taste this tea?

Etc.  The five teas were very different and easily recognizable (Sencha, Oolong, Assam, Ceylon, and a nameless Japan green), although they weren’t all very good teas (according to me).  It was helpful to have the list of questions in front of me while tasting to help me focus on different aspects.  One question gave suggestions of flavor qualities, such as woody, grassy, smoky, seashore, spicy, etc.  This would be a nice thing to have in front of you as a novice or if you are conducting a tea tasting event.

It’s also important to pay attention to what visions or feelings the tea creates for you because this will help you remember the taste later on.  For example, if you taste a tea that instantly brings you to back to a moment of your childhood, say being at your best friend’s house on a summer afternoon, that memory detail will help you later on to remember, “Oh yeah, that’s the tea that tastes like Susie’s house.”  Notes of this kind would be wonderful to include in a tasting journal to help you keep track of teas you really love or hate, much more so than just a rating of 8/10 or something like that.

What I found so fascinating about this Tea Expo class on taste is not just the science of it, but how varied everyone’s perceptions and preferences can be.  Of course, we’ve all noticed that our own taste perceptions don’t exactly match those of our friends, but there was something about having it more scientifically demonstrated under controlled conditions that drove home that point.  Sure, we may talk about “good” tea and “bad” tea, but at the end of the day, all that matters is whether you like it well enough to drink it.  At the same time, to some extent you can improve your palate and learn to discriminate more.  Some of this happens naturally as you taste more types of tea (or wines, or chocolates, or what have you).  I remember when I first started to drink tea, I couldn’t tell a Ceylon from an Assam from a Darjeeling.  Now it’s easy for me to forget that everyone can’t automatically taste those differences, and I’ve been disappointed when I’ve shared my favorite tea with the uninitiated, and their only comment is,” Yes, that’s a black tea all right.”  They didn’t taste what I did.  But eventually, as you familiarize yourself with the beverage, the subtleties present themselves.  The first step is being open to it, then simply pay more attention and practice–and that’s the fun part!

References:

  • Cupping: Sensory Skill Building Workshop, by Scott Svihula, World Tea Expo 2011.
  • www.tastescience.org