Coffee Flavors and Temperature Influence

Coffee flavors and temperature influence post is not about how to drink your coffee or tea. It is more about getting out of your comfort zone, experiencing and enjoying the coffee’s perceived flavor nuances, or any drink for that matter, served at different temperatures.

There is a lot of information out there that discusses the “ideal” and “perfect” coffee serving temperature and many other drinks. Still, the correct answer for me is boiling down to a straightforward rule.

The right serving temperatures are the ones you feel are the most enjoyable while consuming any drink, and that subjectivity actually is the reason that creates the problem of defining what these “ideal” temperatures might be.

Unless one makes a beverage for their consumption, it will be virtually impossible to please everyone due to a lack of objective criteria defining the highly subjective preferences of taste and aroma.
Of course, we can use the sum of averages, gender preferences, statistic results based on lab test experiments, or customer feedback. However, we will still be defining these temperatures based on the majority and not on the absolute one hundred percent agreement from our customers, friends, or volunteer taste subjects.

That automatically eliminates the words “perfect” or “ideal” as being part of the definition of what should be the hot/cold temperatures and introduces the more inclusive one “suggested.”
The “ideal/recommended” serving temperatures will always represent the majority of people’s expectations and are closely related to their psychological flavor perceptions.

We all try to do while we make or serve drinks is to manage someone else’s expectations. If we don’t meet that minimum goal, we will have lots of disappointed people, and if we are running a business, we will have a tough time ahead of us.
As for the minority, that’s where the serving flexibility and accommodation come to play. Again, if we are business, we can have a section on the menu offering coffee, tea, beer, wine, or liquor at different temperatures than the industry recommended ones.

At that point, since there is no such thing as perfect serving temperatures, one might ask the question, “What is the point of trying to define something so subjective when it is clear that we will never be able to achieve 100 percent accuracy?”

There are two possible answers to this question.

1. Serve the drinks based on the accumulated experience of customer feedback you collected over the years, and don’t bother with any suggested or “ideal” temperatures; it is an easy way of keep doing what you are doing, it saves time and effort of learning something new, but at the same preventing you from offering new experiences to your customers or friends.
   
2. The second option will be to focus on what the benefits might be for your clientele and business, if you were to explore the different serving temperatures.

Option one is pretty straightforward, do what you’ve been doing all along, and serve the drinks according to industry recommendations and clientele feedback.

Option two is about exploring how different temperatures influence the flavor of the drinks and their effect on customer experience. Looking at the possibility that might be another way of serving drinks, experimenting, and giving yourself the chance to provide, hopefully, unique and different sensory experiences to your patrons or friends.

I’ve always been interested in finding the answers to why and how the flavors have such a significant influence on human behavior, and the corresponding answers may or may not always lead to doing things differently.

One thing is for sure, the road to learning and understanding the process of what is happening in our beverage and how we perceive the taste under different temperatures will benefit our conquest of becoming better in the craft of bartending.

Taste and Temperatures

What is taste and how do we define it?

While we are drinking or eating, we are constantly assessing the quality and the personal satisfaction from the products we are consuming. The usual outcome of this process sounds like “It tastes like…”. The word taste has become an everyday expression/substitute for flavor.
The taste is only one part of the flavor perception; it is identified by its qualities such as:

• sweet – reflecting the presence of carbohydrates/sugars
• sour – acidity
• salty – sodium and minerals content
• bitter – potential toxins
• umami/savory – glutamates and other amino acids, present in seaweed, meat broths, and fermented products, indicate protein.
• fat – more mouthfeel than flavor.
• astringency – similar to fat in a way that it is more feeling than taste.

Each one of them detects different nutritional components in food or beverages¹.
The last two qualities are not officially recognized yet as taste, but there is considerable evidence of their taste sensations.

• Fat – a fatty acid transporter CD36 is found in the oral cavity on human taste buds, and a decreased sensitivity to fat taste is also associated with increased consumption of fat.
  • The fat sensation was classified as a taste as early as 330 BC by Aristotle and later in a 1531 AD text on physiology by Jean François Fernel. More recently fat has been associated with texture, flavor release, and thermal properties in foods, but not with the sense of taste². 

• Astringency – tannins in tea or red wine can cause this kind of sensation, usually felt as roughness on the tongue. Imagine forgetting a tea bag in tea for a long time and then having a sip.

The primary organ responsible for taste is the tongue, which contains taste receptors that identify non-volatile chemicals in foods and beverages. It provides us with the ability to identify their taste qualities.

It has to be mentioned here also that taste is hardwired with our brains, we are born with it, as opposed to smell recognition, which can be learned over time.

The main purpose of the taste is to protect us from any food/drinks that potentially can be harmful, and It has evolved as a vital survival mechanism in mammals. Think of it as a gatekeeper, sweet might be good, but bitter or sour may signal spoiled food.

Additional flavor receptors

As I mentioned before, taste is only one of the contributors to the perceived flavor; the other parts are touch-mouthfeel, smell, vision, and sound. Each of them plays a vital role in providing the necessary information to our brain, where all the decisions on whether we like or dislike a particular food or drink are made.
Other variables also influence a particular flavor decision; they are triggered lots of time on a sub-conscience level and influenced by memories, past experiences, mood, ambiance, and cultural background.

Touch – Mouthfeel

The “feel” of a food or beverage, produced by mechanical stimulation and mediated by the tactile sense (the sense of pressure, traction, and touch), is an essential but often overlooked aspect of flavor.

The touch system tells us that there is a substance (food or drink) in our mouth, and it triggers the taste (the gatekeeper) to inspect that substance. The results are sent to the brain, where a decision is made on whether the substance is safe to be ingested.
Once we get the go-ahead that the food/drink is safe, the touch/motor system is activated again, resulting in breaking down the food in our mouth or for liquids like wine, swishing it around slowly with tongue, and exposing it to the taste buds.

Smell

Our sense of smell is responsible for about 80% of what we taste. Without our sense of smell, our taste is limited to only five distinct sensations: sweet, salty, sour, bitter, umami. The smell is two senses combined in one;

• Orthonasal olfaction – a sense of smell through our nose while we breed in and sniff a particular substance.
• Retronasal olfaction – a sense of smell triggered by breading out. It occurs in the mouth and it contributes to the flavor of foods or drinks. It is commonly associated with the sense of taste as it is closely fused with taste and touch.

In the case of drinking wine, we are swishing a sip of wine in the mouth, and at the same time, we are breathing out, causing the volatile molecules to exhale and create a flavor sensation.

The retronasal smell is a fascinating sense in a way that we often think of it as taste, and it is the reason for expression like “it tastes like lilacs, grass, or any other aroma.” That’s impossible as taste is usually associated only with sweet, sour, salty, bitter, and umami.
Next time while having food or drink, try not to breathe out right away, make sure you are doing it safely, and then eat or drink slowly to feel the difference in flavor release and enjoyment.

Vision

It has a significant influence on how we perceive the flavor. Lots of time, it forms our perception of it even before trying it. As a bartender, I had to make numerous drinks based on the simple request, “I want to have the same drink as the person over there is having,” an order based only on drink appearance without even knowing the ingredients in it.

Vision sense is about the food or drinks appearance and the ambiance, is it clean, cozy, comfortable, bright, dark, etc. All these sensory inputs are instantly connected to our memory banks and related to previous experiences, good or bad, which leads to the most likely internal decision of “I like being here or I’d rather spend my money somewhere else.”

Advertisers, for instance, are very well versed in creating visual cues and promoting products in the most enticing possible way.

Sound

The sound is related to the texture of food, drink, and our surroundings. Hearing the sound of crunchy food, a clean pour of wine and beer, or a noisy/distracting background adds dimension to the flavor feedback.

Temperatures

Temperatures play an essential role in intensifying or masking aromas and tastes qualities. Higher temperatures increase the perceived bitterness in the beer and coffee, and lower temperatures can eliminate or reduce to minimum scents in drinks such as cognac, rakia, or grappa.

These are just a few examples of flavor manipulation; whether these changes are desirable is not important, as the decisions are based on personal preferences. The more important result is using different serving temperatures to experience new flavors.

Let’s use coffee as an example of a beverage equally enjoyable served hot and cold, and try to answer a few questions;

1. What is the suggested brewing and serving temperature?
2. Does lower temperatures reveal or enhance any additional aromas? Not perceived otherwise.

Before roasting, the green coffee beans have a slight aroma but are loaded with chemical compounds waiting to be extracted and enjoyed later on.

The development of these aromas begins with the roasting process, where the different temperatures cause the release of specific aromas related to and associated with particular toast levels.
“The impact of roasting on taste comes from the degradation and formation or release of various chemical compounds through the Maillard reaction, Strecker degradation, decomposition of amino acids, quinic acids and lipids.”³

After the roasting and production cycle is complete, it is time to enjoy the delicious flavor of coffee, which leads us to the next important step- brewing.
According to the National coffee association, the suggested brewing temperature is using water between 195 to 205 degrees Fahrenheit for optimal extraction, not to be confused with serving one, which is much lower than that.
Brewing water temperatures for teas are lower than that, and it depends on the type of tea as well.

We need that higher brewing temperature to extract fuller flavor profiles, and at the same time, we have to factor in a few more variables.

• Different temperatures are extracting different chemical compounds.
• Type of roast being used. For darker roast optimal water temperature is around 185 degrees Fahrenhiet, as the really hot water may extract some burn/ash aromas.
• Coffee brewing methods.

Serving Temperatures

Numerous studies have been done on consumers’ preferred hot beverages serving temperatures, and all of them have one thing in common. The desirable and safer range is between 130 to 160 °F (54.4 – 71.1°C).

For coffee brewing, the hot water was passed over coffee grounds into a carafe, which led to decreasing of temperature from 3 °C (∼5 °F) for insulated carafes to about 7°C (20°F) for uninsulated carafes, the range was dependent also on the type of the brewing equipment.

At that point, the coffee temperature drops approx. 10-15°C (20 to 25 °F) in-room environment in 5 min. That time doubles if the carafe has a cap on it, which brings it to the taste within the preferred temperature range of 130 to 160 °F (54.4 – 71.1°C).

The studies were done using black coffee, and the preferred temperatures in the table are as per the taste preferences of the volunteers.

Preferred temperatures based on the different studies.

Combined Recommended Coffee and Tea brewing/serving temperatures.

Perceived coffee flavors under different temperatures

The recommended coffee serving temperatures according to National Coffee Association was between 180-185°F. The recommendation was currently removed from their website. At the moment, it is recommended to be mindful and careful of the coffee temperatures being served and enjoyed.

These coffee flavor profiles are guidelines of what one may expect at a certain temperature level. They are not written in stone, thankfully. They are highly dependable on the coffee origin, type, level of roasting, water, brewing, and probably the most important, the human element. We judge what we taste; our perceptions are uniquely individual and depend on our brain olfactory system to interpret the flavor we experience.

According to Karel Talavera Pérez, professor of molecular and cellular medicine at the University of Leuven in Belgium, studies recording the electrical activity of taste nerves demonstrate that,

“The perception of taste decreases when the temperature rises beyond 35C”.

When the temperature goes higher, we tend to taste less and less. The higher temperature triggers the cautionary safety signal warning us of potential burning and overpowering the other taste perceiving receptors.
That also explains why some beverages, to appreciate their flavor profile fully, are best tasted at room temperatures. The same applies if the temperatures are close to zero or below, the strength of the coffee aromatics will be diminished.

There is a difference between tasing and drinking on a side note here.

• Tasting is as per suggested temperatures under which a full flavor profile can be perceived.
• Drinking – there are no rules, have your drink the way you are enjoying it the most.
  

Tasting notes are a collective effort/collaboration to get closer to describing the actual flavor of a product to someone who hasn’t tasted it yet.

Flavor perception is fascinating topic; it’s about forming flavor images, acting upon them, and exploring our decisions on what we eat or drink.

Suggested drink serving temperatures

Using serving temperature, one can manipulate the flavor of a drink. The general rule of thumb is that the higher the temperature, the more robust flavor is perceived, but the most affected part of the smell, especially the Orthonasal part (the smell we detect through the nose).

This is a well-known fact by many drinks manufacturers and advertising companies; the colder the drink, the less aroma is perceived, and more of the particular beverage can be consumed. A couple of examples of that practice are beer and brandy.
If one is to have a subzero served beer and especially brandy will notice that most of the aroma is not there anymore. By eliminating the smell, new potential customers, who didn’t like the beer or brandy aromas, can be attracted to try these products and thus increase the sales.

I’m not saying this is bad or good; it is just another experience. I tried Remy Marten VSOP served at subzero temperature, and I did enjoy it; it tasted like chocolate with the long-lasting aftertaste, easy to drink, not much aroma, perfect for people who don’t like cognac.

1. https://flavourjournal.biomedcentral.com/articles/10.1186/2044-7248-4-5
2. http://www.australasianscience.com.au/article/issue-january-and-february-2012/taste-fat.html
3. Satrijo Saloko, Yeni Sulastri, Murad, and Mira Amalia Rinjani, 
   “The effects of temperature and roasting time on the quality of ground Robusta coffee (Coffea robusta) using Gene Café roaster,” AIP Conference Proceedings 2199, 060001 (2019) https://doi.org/10.1063/1.5141310