/ Coffee science, Education / By Jesper Alstrup
The article was written and published by Coffeemind – https://coffee-mind.com/
This post will be divided into two parts. The first covering the investigation of the term ‘body’ itself, and the second will include a peek into the world of sensory science and how we test for differences in ‘body’ between coffee samples.
One of the core concepts used to describe the flavours of coffee is ‘body’. But what is it and do we even agree on the same definition?
When I first got into coffee I was amazed by the attention to detail that every person seemed to have. Everyone wanted to get the latest information on how to perfect their cup. A central word I heard thrown around was ‘body’. How do we get more ‘body’ in the coffee?!
Looking closer, a problem started to appear: What is ‘body’ even? No one seemed to really know, so I quickly found myself on a journey to investigate this mysterious concept. Let’s have a look at what I found…
Take a second and consider the most precise definition that you can come up with…
Body is, according to the SCA, defined as:
Body | The quality of Body is based upon the tactile feeling of the liquid in the mouth, especially as perceived between the tongue and roof of the mouth. Most samples with heavy Body may also receive a high score in terms of quality due to the presence of brew colloids and sucrose. Some samples with lighter Body may also have a pleasant feeling in the mouth, however. Coffees expected to be high in Body, such as a Sumatra coffee, or coffees expected to be low in Body, such as a Mexican coffee, can receive equally high preference scores although their intensity rankings will be quite different.
At first glance, this might seem like a relatively simple and straightforward definition. However, if we look a little bit closer we will notice that it is not a very precise way of defining the concept.
Let’s try and dissect the definition from above.
‘Body’ is said to be a tactile feeling in the mouth, i.e. what science calls oral-tactile texture(Lawless & Heymann, . This includes all sensations such as grainy, chewy, sticky, hard, crunchy, astringent, and so on. In short, tactile feelings can be many things.
The next part of the definition describes the relationship between intensity and quality of ‘body’. This is where it gets tricky! A high intensity ‘body’ can typically have high quality ‘body’, but a lower intensity ‘body’ can also have high quality ‘body’. I can understand if you are a bit confused at this point, so am I.
Surprisingly, research publications are not much clearer in their definitions. Several papers and authors define ‘body’ as synonymous with texture and mouthfeel (Everage, 2002; Illy, 2002; Esteban-Díez, González-Sáiz and Pizarro, 2004; Riberiro, Ferreira and Salva, 2011; Gloess et al., 2013).
In essence, the definition from above includes all types of tactile sensations, along with a quality and intensity dimension. I would argue that this is not a very precise definition, but let’s see what coffee professionals say.
As part of my Master’s thesis I distributed a questionnaire to get information on community perception of ‘body’. One of the questions openly asked what determinants of high body in coffee might be. The results are shown in the table below:
| Determinants of high body | Percentage |
|---|---|
| Viscosity (feeling of thickness) | 18,88% |
| Coating (oily feeling) | 13,27% |
| Roast color | 12,24% |
| Roasting profile (timing) | 11,73% |
| Particle size (grind setting) | 10,71% |
| Water quality | 8,67% |
| Grittiness (feeling of small particles in the brew) | 5,61% |
| Sweetness | 5,10% |
| Intense aroma | 5,10% |
| Bitterness | 3,57% |
| Astringency | 3,06% |
| Acidity | 2,04% |
The main point of the question was to get an idea of which things people associate with high ‘body’. As you can see, most people included characteristics such as viscosity and coating, which are tactile sensory attributes. Yet, a few people include the different taste attributes or aromas as a contributor to ‘body’.
Another question asked respondents to rate their agreement to certain statements. One of them read: Body is related to overall mouthfeel, taste and aroma. The distribution of people agreeing or disagreeing with the statement is shown in the illustration below.
Overall it appears that ‘body’ is a very ambiguous concept, and we do not all use the concept in a similar manner. This is a problem when trying to discuss and evaluate coffees based on such concept.
Let’s ask the experts
Surely there must be an expert out there who could clarify this for us. I contacted 8 different coffee professionals with 15-25 years of experience in the industry, and conducted interviews of around an hour with each of them.
I will not bore you with all the details, but the main takeaway was that body is related to mouthfeel. It does not include aromas or tastes! However, the concept still appeared extremely unclear. The table below summarizes the terms used to describe ‘body’ in the interviews, divided into positive and negative categories.
| Positive | Negative |
|---|---|
| Viscous | Astringent |
| Weight or heaviness | Light |
| Coating | Gritty |
| Mouthfeel | Watery |
| Smoothness | Rough |
| Texture | Thin |
| Dense | Chalky |
| Syrupy | Sharp texture |
| Creamy | Dirty |
| Silky | Oiliness (rancid) |
| Velvety | Tea-like |
| Thickness | Dry |
| Tea-like | Slimy |
| Oiliness (soft) | Unconcentrated |
| Physical nature of the brew | Coating |
| Buttery | |
| Perception of substance | |
| Fullness | |
| Salivating |
I identified two groups of people in the interviews. Two ways of approaching the definition of ‘body’.
The first group defined ‘body’ as purely tactile, relating to the thickness or viscosity of the brew. They acknowledge that other types of mouthfeel may exist in coffee beside ‘body’.
The second group defined ‘body’ more synonymous with mouthfeel, meaning the evaluation of ‘body’ in coffee includes a range of different types of mouthfeel to be considered. The evaluation is furthermore divided into two parts, namely quality and intensity. Intensity of ‘body’ is evaluated similar to the first group, focusing on thin versus thick, high versus low viscosity. The quality of the ‘body’ included terms such as smooth, gritty or astringent to describe the pleasantness of the ‘body’.
That it is extremely confusing. We cannot properly discuss a sensation if we are talking about completely different things.
If I say my coffee has high body, what am I referring to then? Based on what we learned, high body could mean many things. For example, it could be thick and viscous, or it could be thin and smooth. Depending on the internal definition of the concept for each individual we could end up in longer discussions about ‘body’, simply because we misunderstand each other due to vague definitions of the concept…
Let’s get inspired by what is done in science.
First of all, we need to separate intensity and quality. This should not be discussed at the same time, and should not be using the same word. Quality is extremely difficult to evaluate since it involves subjective opinions if not carefully defined. The discussion of quality demands its own post, so I will not elaborate further at this moment.
We need to have clear definitions that allow for a similar interpretation by tasters, preferably with references to illustrate the meaning of a concept (Lawless & Heymann, p159). Vaguely defined terms are simply NOT useful when discussing in a tasting panel, or providing feedback to the farmer.
You can create much clearer communication by splitting the concept of ‘body’ into smaller parts that encompass the meaning that the ‘experts’ tried to describe.
Let’s start with intensity focused attributes. We can define ‘body’ as the thickness or viscosity of the beverage. A high ‘body’ would indicate a very thick and viscous liquid, while a low ‘body’ would be watery and thin. Keep it at that. Perhaps we lack some detail, e.g. there is a creamy or coating sensation in the coffee that was not quite captured by this definition of ‘body’. Let’s add ‘coating’ to the list of attributes that we are evaluating then. This could continue until you have the descriptors you feel like you need. The most important is having a clear concept for each of them.
How about the quality then? According to the experts, the main thing that was captured by the quality aspect was whether the coffee had a nice smooth sensation, or whether it was rough, gritty or astringent. Well, we can add those types of descriptors! For example, we could rate the grittiness of the coffee objectively – does it have a sensation of smaller particles in the brew? Does it feel astringent and dry on the tongue?
The table below provides suggestions on how to go through this process with definitions and references. Exactly what should be the reference is of course up for discussion, so here are just some ideas.
| Attribute | Definition | Reference |
|---|---|---|
| Body | The perceived thickness or viscosity of the brew. | High body: Solution of xanthan gum in water (food gelling agent) Low body: Pure water |
| Coating | The coating sensation of fats covering the oral tissue. | High coating: Cream Low coating: Skim milk |
| Grittiness | The sensation of small, hard particles in the brew. | High: Flour mixed in water. Low: Pure water |
| Astringency | A dry, sandpaper-like sensation on the tongue. | High: Over extracted Earl Grey tea Low: Pure water |
The World Coffee Research Sensory Lexicon may be of inspiration when defining and creating references for sensory attributes. I would recommend you to have a look at that.
I do not claim that this is the correct definition of ‘body’. This post is merely an illustration of the inherent issue in its current form. The main goal of the post is to promote critical thinking, awareness, and to perhaps inspire a new, less ambiguous way of discussing mouthfeel sensations of coffee.
In conclusion, no one agrees on what ‘body’ is, and how we can describe it. It is a common problem in the industry, where concepts are often loosely defined. This makes it a challenge to have meaningful discussions about flavour, and to provide relevant feedback to product developers, farmers, and more. You need to start being more critical of the terms you are using to describe the coffee sensation – your friends and colleagues may have their own definitions of certain concepts. Lastly, start using references. It is an easy way to align concepts between people.
How do you normally describe ‘body’ to friends and colleagues? Are there other attributes or concepts you hear and find confusing?
References:
