What is mouthfeel?

The eas­i­est way to explain mouth­feel is to explain what it is not. Simply put, mouth­feel is the over­all expe­ri­ence of food or drink in the mouth – minus the taste and aro­ma. The term is often used by som­me­liers, who talk about how wine is feel­ing in the mouth, but every­one who works with ‘taste’ should use the term; the taste is just part of the over­all expe­ri­ence. In order to take a holis­tic view of the din­ing expe­ri­ence, it is impor­tant to work with the whole mouth feeling.

Taste and aroma

Our expe­ri­ence of food and drink is com­posed of taste, aro­ma, and mouth­feel. It is eas­i­er to under­stand mouth­feel and its sig­nif­i­cance if you first under­stand what dis­tin­guish­es taste and aroma.

Taste is the expe­ri­ence that comes from the recep­tors on the tongue. These are the four basic tastes: sweet, salty, sour, bit­ter. Recently, uma­mi has been rec­og­nized as the fifth basic taste, as researchers have suc­ceed­ed in show­ing that we have taste recep­tors that rec­og­nize umami.

Aroma is real­ly the same as smell. We have about a thou­sand dif­fer­ent smell recep­tors that have the abil­i­ty to rec­og­nize dif­fer­ent types of odor­ants. When we eat, fra­grances are released that enter the nose and reach the smell recep­tors. This can hap­pen in the duct that con­nects the oral cav­i­ty and nasal cav­i­ty (retronasaly), or from the mouth and nose.

Mouthfeel

Now we come to the mouth­feel. Initially, I wrote that it is the over­all food expe­ri­ence minus the taste and aro­ma. That is large­ly true, but I will now explain mouth­feel in more depth.

We are equipped with taste recep­tors and smell recep­tors, but there is a third ele­ment, that is often over­looked when it comes to food. That is the somatosen­so­ry sys­tem. Simply put, it is our abil­i­ty to feel. The somatosen­so­ry sys­tem is found through­out the body but is par­tic­u­lar­ly sen­si­tive in the mouth.

Mouthfeel is part of the somatosen­so­ry sys­tem. The sys­tem sens­es the phys­i­cal expe­ri­ences of pres­sure, vibra­tion, fric­tion, and tem­per­a­ture dif­fer­ences. Receptors in the tongue, teeth and oth­er parts of the mouth help cre­ate the over­all mouthfeel.

Mouthfeel is some­thing that the con­sumer rarely talks about – at least not explic­it­ly. But at sec­ond thought, we real­ize that when some­thing does not real­ly ‘taste’ as it should, it often regards mouth­feel. Chips that have become soft, pas­ta that has been over­cooked, or ice­berg let­tuce that has lost fresh­ness and crispiness.

The phases of mouthfeel

Mouthfeel becomes more under­stand­able and relat­able if we divide it into dif­fer­ent phases:

The tactile phase:

First comes the tac­tile phase. It is the imme­di­ate feel­ing of touch in the mouth. Imagine a fork with meat, sauce, and rice – per­haps a chick­en stew. When the tongue and mouth are just rub­bing at the hot chick­en, the tac­tile phase becomes very clear. You dare not to ful­ly dig in, because of the heat.

The chewing phase:

When you then dare to chew and real­ly enclose the food prop­er­ly with your tongue and palate, the mouth­feel changes as the chick­en, rice and sauce stick togeth­er into one body.

The subsequent phase:

After you have swal­lowed, the after­ef­fect aris­es. How do your mouth and throat feel? Do you expe­ri­ence cool­ness, dry­ness, heat, or slim­i­ness? Your mouth is emp­ty but the food may have left an increased tem­per­a­ture in the mouth, cre­at­ed dry­ness, or left a burn­ing spice experience.

The psychological phase:

Finally comes the psy­cho­log­i­cal after­ef­fect. How does it feel after the meal? This phase can, for exam­ple, be described as refresh­ing, thirst-quench­ing or sat­u­rat­ing. In the case of the hot chick­en stew, a feel­ing of gen­er­al sat­u­ra­tion and well-being is felt. A fat­ty sauce and oth­er calo­rie-rich acces­sories may make you drowsy.

The Ketchup experiment

It is not sur­pris­ing that taste, aro­ma, and mouth­feel may be a bit confusing.

On the one hand, there are food expe­ri­ences that are dif­fi­cult to clas­si­fy. For a long time astrin­gency (the dry sen­sa­tion in the mouth that tea or red wine can give rise to) was con­sid­ered a taste expe­ri­ence but is now con­sid­ered to be a mouthfeel.

On the oth­er hand, the three inter­act with each oth­er. Depending on how we process the food in the mouth (for exam­ple, how vig­or­ous­ly we chew), taste and aro­ma sub­stances are released in dif­fer­ent amounts.

This inter­ac­tion is illus­trat­ed in an inter­est­ing exper­i­ment that the food researcher Ole G. Mouritsen and the chef Klavs Styrbæk describe in the book Mouthfeel: How Texture Makes Taste.

The exper­i­ment cre­ates two types of ketchup. The only dif­fer­ence is the pro­cess­ing; one is made com­plete­ly smooth and the oth­er has pieces that offer some chew­ing resis­tance. Although the same amount of the same kind of ingre­di­ents is used, test sub­jects, who taste both, say that they taste com­plete­ly different.

Is it possible?

The answer is both yes and no.

Both kinds of ketchup taste the same, but the mouth­feel dif­fers so much that you think they taste dif­fer­ent. It’s easy to believe that the two ketchup vari­eties are actu­al­ly dif­fer­ent vari­eties with dif­fer­ent ingre­di­ents. Strange, right?

As the coarse ketchup requires chew­ing, aro­mas are released that affect our taste and smell. As a result, the taste seems to be enhanced, but in fact, it is the mouth­feel and aro­mas that togeth­er make us expe­ri­ence a taste change.

Expectations

Mouthfeel is great­ly affect­ed by our expectations.

In their book, Mouritsen and Styrbæk talk about anoth­er exper­i­ment in which par­tic­i­pants were offered a puree. The ques­tion was how many of the par­tic­i­pants could iden­ti­fy that the puree was made from cabbage.

Only five per­cent succeeded.

Cabbage is dif­fi­cult to rec­og­nize. But even famil­iar ingre­di­ents are a chal­lenge; only every oth­er par­tic­i­pant rec­og­nizes toma­toes with­out the help of the mouthfeel.

Another exam­ple regard­ing the sig­nif­i­cance of expec­ta­tions is from a food fair in the Netherlands. Sacha and Cedrique are two guys who turn McDonald’s food into snacks that passers­by can taste in the belief that it is an organ­ic fast-food alter­na­tive. The response? Look here:

https://​youtu​.be/​4​Q​a​6​Q​X​B​x​xWw

The tastiest food we’ve eaten

In an old issue of a youth mag­a­zine, a lit­tle girl is telling us about her school trip. The fire­place goes out dur­ing the night in the old cot­tage. In the morn­ing, it is minus sev­en degrees Celsius and the packed food has frozen and has become hard as a rock. The girl and her friends use an axe to split the spaghet­ti. Despite these hard­ships, the expe­ri­ence is described as fun and the food tast­ed won­der­ful after all the efforts.

It is easy relat­ing to the girl’s sto­ry. We prob­a­bly all have sim­i­lar sto­ries where sim­ple and every­day food is trans­formed into the best we have eat­en. Perhaps after a day at the lake, a sports activ­i­ty or a moun­tain hike.

But as a food pro­duc­er, the prod­uct must always main­tain high qual­i­ty. Not just dur­ing excur­sions and out­door activ­i­ties. Taste is still an impor­tant mea­sure. But if you do not take into account the mouth­feel, it may not mat­ter how good the flavours are. And when it comes to sug­ar sub­sti­tutes, there is the risk that both taste and mouth­feel are compromised.

Sugar and mouthfeel

If you want to replace sug­ar, there are a num­ber of alter­na­tives. But it is anoth­er sto­ry if you want to replace sug­ar, and at the same time, main­tain mouthfeel.

If sug­ar is removed to reduce calo­ries and blood sug­ar lev­els, the sweet­ness can only be replaced with a high-inten­si­ty sweet­en­er such as ste­vi­ol gly­co­sides. Three grams of the herbal sweet­en­er is enough to reach the same sweet­ness as one kilo­gram of sug­ar. But then the sug­ar bulk and tex­ture will lack, which con­tributes a lot to the mouth­feel. Therefore, some­thing else is often need­ed to give the same mouthfeel.

Finding a com­bi­na­tion of high-inten­si­ty sweet­en­ers and oth­er ingre­di­ents that give the same sweet­ness and mouth­feel is dif­fi­cult. It is time-con­sum­ing and requires spe­cial­ist exper­tise that not every­one has. Simply put: It is dif­fi­cult (to put it mild­ly) to find the right com­bi­na­tion and dosage.

Finally

In the e-book The Sweetening jour­ney, we go fur­ther in explor­ing the chal­lenges of replac­ing sug­ar with few­er calo­ries but main­tain­ing good qual­i­ty prod­ucts. If you have not already down­loaded and read it, then it is time to do so. You find it here.