Continuing our exploration into coffee’s brilliant and complex sensory range, here we turn to mouthfeel. From terminology and science to taste and benefits, we turned to our Head of Coffee, Stephan Gray, to help us explore what mouthfeel means for your cup, and what to look out for.
WHAT IS MOUTHFEEL?
Flavour is a combination of aroma, which is linked to smell, and taste, which is linked to the mouth. Touch is a crucial part of the taste experience; we refer to it as ‘mouthfeel’. ‘Body’, sometimes used synonymously with mouthfeel, refers to the physical intensity or ‘weight’ of the liquid in the mouth— whether it is ‘light’, ‘medium’, or ‘heavy’. Mouthfeel captures this in combination with the qualitative aspects we’d use to describe that sensation; a coffee with a low intensity body might be positively described as ‘tea-like’ or ‘silky’, or negatively as ‘watery’ or ‘thin’; a coffee with high body might be ‘creamy’, ‘velvety’, or ‘cloying’.
Mouthfeel is texture—the weight or fullness that is detected in the mouth. We don’t taste body, per se; it is a sensation we feel, one with the power to influence the holistic gustatory experience, thanks to gustation’s many combining factors that touch on all the senses: taste, aroma, texture, sound, and most likely even sight.
WHAT IS MOUTHFEEL / BODY IN COFFEE?
Mouthfeel is among coffee’s key attributes, a tactile marker alongside temperature; we perceive a liquid’s body through small movements of the tongue against the palate that sends information about viscosity and texture to the brain. The determining factors are organic compounds – called lipids – that are insoluble in water.
Body emerges from a coffee when we extract flavour and aroma compounds from ground coffee into water. The process of extraction is how soluble and insoluble compounds make their way into the cup. The solubles are the substances that dilute in the water. The insoluble are solids and oils that remain suspended in the liquid instead of dissolving—things like protein molecules and certain coffee fibres. These insolubles, especially the oils, increase body.
‘Astringency’ is a term often used in connection to mouthfeel, too. But, while sometimes admired in wine and tea, astringency is generally considered undesirable in coffee. Astringency is the body’s up-puckering, dry mouth reaction to certain acids in unripe fruit (which could mean immature beans for coffee), sometimes mistaken for sourness, but astringency can also give a sensation of papery-ness. Often in coffee it is a result of under-extraction, but it can also indicate a defective or poorly processed bean.
WHY DO SOME COFFEES HAVE MORE BODY THAN OTHERS?
There are numerous factors that can enhance or downplay the presence of body in your coffee, from process and roasting through to brewing method.
Naturally processed coffees tend to present a bigger rounder body, due to them resting to dry in the cherry—more of the sugars and compounds from the fruit find their way into the seeds which end up as coffee beans. Washed coffees on the other hand are appreciated for producing a clean cup, with clarity and a more delicate body, because the fruit pulp is cleaned off them prior to drying. Honey and pulped natural process coffees sit in the middle—done well, they will have the clarity and brightness of a washed coffee and some of the body of a natural. In general, the more mucilage left on the coffee cherry during drying, the more body in the cup.
Fermentation – a natural chemical reaction that occurs between sugars and water (two things that coffee cherries contain plenty of), and a key part in the processing of all coffee – can also enhance and refine a coffee’s best attributes, including body. Experimenting with fermentation can bolster or soften sweetness, acidity, and body, but the process, which can take on many forms, including dry (aerobic), and wet (anaerobic), needs careful monitoring: key variables, such as time and temperature, have a big impact on the overall flavour development of the coffee.
Green coffee can be roasted to emphasize or downplay the sensation of body in your final cup. Controlling the heat all the way through a roast will accentuate the desired profile: stretching the Maillard phase prior to the first crack, where sugars caramelise, can increase the intensity of body. For example, a “syrupy” mouthfeel is related to the perception of particular carbohydrates that are released in greater levels with the stretching out of the Maillard Reaction—this can lead to more melanoidins which, in turns, means more body.
Since oils influence body, how much oil your brewing method (and filter) allows into the cup has an impact on the final level of body detected.
Thanks to the higher brew ratio of coffee to water, and the use of high pressure (rather than gravity) for extraction, which produces higher lipid counts, espresso is known for its fuller body; the crema of an espresso is filled with oils and melanoidins, which produce body.
Pour overs are better known for their clarity, often with a softer perception of body; the AeroPress is popular for its ability to be able to enhance or lighten the sensation of body, thanks to its versatility of design, allowing for brewing recipes to be adapted by grind size and time variables. The Chemex, in part due to the use of thicker filter papers, produces a coffee with clarity and a much lighter perception of body.
In all brew types, extraction is a process that takes place over time, where the most soluble material (typically acids and fruit salts) is extracted first, and the least soluble (dry distillates and organic matter) at the end. Body emerges in the latter part of the extraction process, which is why a ristretto or an under-extracted pour over will taste a lot thinner or lighter than an espresso or fully-extracted brew.
Excessive heat can diminish your ability to fully perceive body, temporarily anesthetizing the taste buds, and dampening overall taste perception. This is why, when a coffee is cupped, the coffee is sampled at difference stages in temperature.
Taste is a highly personal experience: when it comes to body in coffee, enjoy exploring processes and brewing methods to discover your personal preferences.
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