The tactile sensations of coffee: astringency, smoothness, earthiness

The tactile sensations of coffee are different and we can divide them into:

astringency: this sensation occurs due to the decreased lubricating power of saliva. This sensation is triggered by the presentation of tannic substances of woody origin (polyphenols) that drop a protein (mucin) contained in saliva and capable of making the mucous membranes "slippery."

smoothness: this perception is experienced when you feel a "spherical" perception by taking a sip of coffee. It is directly proportional to the content of microscopic solids in suspension in the beverage: it increases as the sweet taste and the dissolved fatty substances in the coffee increase, while it decreases as the bitterness and acidity increase. Normally in espresso coffee a high smoothness is almost always accompanied by a high body and creaminess of the beverage.

Earthiness: this sensation is noticeable on the surface of the tongue and is a sensation triggered by a decrease in the lubricating power of saliva. Earthiness goes hand in hand with astringency (it may precede and/or accompany it) and is often combined with a heightened bitterness.