“Taste is complicated…We have just three photoreceptors for vision, but 25 receptors dedicated to sensing bitterness alone.”

-Robert Margolskee, director of the Monell Chemical Senses Center in Philadelphia.

This week, we’re nerding out at Irish Spirit HQ. Our passion for whiskey pleasure has definitely become an obsession. This will be part of a series that will take an in-depth look at the world of whiskey flavours in order to understand the science of tasting. There is a lot to find out about whiskey flavours: where they come from and why we like them so much! For this blog we have matched our own whiskey knowledge with the information we discovered in Ole Mouritsen and Klavs Styrbæk’s book Mouthfeel: How Texture Makes Taste’. 

Firstly, let’s get definitive. Taste and flavour are two completely separate things. Taste is what we ascribe to the basic effect when our tongue interacts with food, drink, any organic compound. Flavour is the combination of taste, plus aroma (and texture to a degree). Scientists agree on 5 distinctive identifiers. Sweet, bitter, sour, salty and umami. However, there are more recent proposals; calcium, piquance, coolness, metallicity, fat, carbon dioxide and kokumi. We won’t delve into the hypotheticals just yet.

Taste is primitive

Our sense of taste is hardwired into our brains to help us survive. It is the first line of defence against disease and sickness. 

  • Sweet: Our propensity to enjoy sweet things is derived from its high caloric qualities. Current understanding is that lactose in breastmilk also stirs us towards sugary goodness from an early age. 
  • Bitter: Give a baby a slice of lemon and put it on Tiktok. This repulsion is there for a reason. Out in the great wilderness, a single berry can make you sick. In the time of hunting and gathering, our tongues told us what was toxic and what was safe.
  • Sour: Despite its importance in modern cuisine, our ability to detect sourness helps us to detect the bad bacteria from fermented foods.
  • Salty: Consumed within reason, potassium and sodium are necessary for the body to function. Salt is responsible for healthy regulation of your nervous system and fluid levels.
  • Umami: The most recent identifier is a close cousin to saltiness, but it primarily involves the taste of protein. The building blocks of life, responsible for growth and repair.

What is taste?

Taste is a physical raw sense. It is the “hearing” to listening. The human tongue has on average around 15-35 papillae per cm2. Those are the bumps on your tongue. Each bump has around 100 taste receptors that link directly to the brain. These same receptors are also on the roof of your mouth, inside your nose and the back of your throat. They are even present in your gut and lungs. If for example you accidentally inhale smoke, these receptors will “taste” the smoke and signal to your brain to cough. If we eat something that doesn’t agree with us…well, we’ll leave it at that. Just like sensing how firm a handshake is, taste, like touch, is a sensation that fluctuates with intensity. Now that we understand taste…

What is flavour?

Broadly speaking, it is perception through the combination of both the taste and the aroma of something. It’s the end of a journey. From the moment you ingest, your receptors start firing signals to your brain. These signals are processed in three ways. The frontal cortex recognises the basic tastes. In a whiskey, we would expect some sweetness, maybe a little bitterness or astringency from the wood maturation. Possibly some saltiness if there was any coastal maturation. The second stage involves your amygdala. This is the emotional center of your brain. This is the fun part of drinking whiskey. It’s where we assess quality through subjective enjoyment and pleasure, and keeps us coming back for more. Lastly, our memory kicks in from the hippocampus. How does this whiskey compare to others? Does it remind you of a significant past experience? Are those my feet? This connection to memory is a mixed blessing however. Having a bad experience with a particular food or drink, can hardwire our perception of something forever. Here’s hoping we keep the good times rolling with whiskey!

No pain, no gain.

Another tool in our sensory arsenal is the trigeminal nerve. These act as an heat/ smoke alarm, so we don’t burn ourselves on hot food, or crack a window when there’s a bit too many cigars and whiskey on poker night. It’s responsible for triggering the body’s defenses against irritants. Crying after eating a chili? That’s the trigeminal gland reacting to capsaicin. Minty freshness chewing gum? That’s a reaction to Menthol. Tingling sensation from a soft drink? That’s the carbon dioxide bubbles. With whiskey, it’s the alcohol. So there’s no shame in adding a few drops to that cask strength dram!

(Here is our current cask strength dram recommendation)

The combination of all these receptors, signals and brain lobes working in sync, converts thousands of chemical compounds into a sensory experience that knows no bounds. The great thing about flavour is it’s subjective. Every person’s experience of flavour is unique, just as every person’s experience of whiskey is unique.

Next week, we take a closer look into how best to taste whiskey, some do’s and don’t, and how to get true value for money!