What causes an "aftertaste"?
Why do we sometimes get a different taste of food after we swallow it?
Here is a good article on the subject. The basics of it are that how we perceive flavor is based on texture, temperature, smell, and taste. Flavor here is separate from taste, as flavor is the entire ensemble of senses coming together to allow you to experience food. While there is no definitive consensus, as how we perceive flavor is not yet entirely understood, the leading theory on aftertaste is that it is our bodies experiencing flavor after the elements of temperature, texture, and smell are gone. This leaves us to process flavor with only the 'taste' of what we had eaten left.
Disclaimer: I have no prior knowledge on this subject beyond what I just researched on the internet. The website is a wordpress site, but it cites published research to back up its claims. If someone in this field disputes what I've said, they know much more than me and are actually qualified to give answers.
Citations given on the website: http://www.sciencedirect.com/science/article/pii/S0092867400806972
Another factor is various impedance of flavors. For example something with a slight metallic flavor overpowered by salty or floral flavor, but remaining after that has passed as some flavors remains longer than others. A second factor to consider is that the after taste may actually be a component of the whole flavor but when mixed with the other factors make up part of the overall flavor.
I doubt it is a taste that comes after as much as a taste that remains after the others have muted.
I actually learned a little about this in my grad school qualifying exams.
One aspect is the binding affinity of certain chemicals to your taste receptors. Take a chemical like, for example, aspartame. You have a bunch if different taste receptors in your mouth- sweet, salty, a whole slew of different bitter ones, sour, etc etc. Aspartame has a VERY high binding affinity to your sweet taste receptors (way higher than real sugar!), so when you first put it in your mouth it quickly binds to your sweet receptors and you taste sweet very strongly. But aspartame also has a weaker binding affinity to bitter taste receptors. So as you have it in your mouth longer the chemical starts to bind to your bitter taste receptors too and so you get a bitter "aftertaste."
This is just one aspect of what causes aftertaste, but it's a nice simple one at least.
exposure to different conditions. In liquor and beer tasting, opening your mouth only slightly while swishing can change and open your palate to flavors that you weren't able to taste before. The same goes for destroying certain ones with the introduction of oxygen. Which is why whiskey and beer drinkers always taste with a closed mouth for a few seconds before opening their mouth.
Someone else can elaborate further, I'm drinking PBR and shouldn't be responsible for this.
You've gotten the sequence of metabolism the wrong way around.
Starches are broken down by enzymes such as amylase in the saliva, and the starches are converted into sugars.
So if you chew on a potato for long enough, it will taste a bit sweeter.
Or it could also be a neuron relaxation response, like getting used to having a watch on your hand and then taking it off.
My new favorite motivation motivational quote
If you chew on a potato for long enough, it will taste a bit sweeter
Possible, but it's such an acute response and very little refractory period. I'd assume if it were something like this, the next bite would simply taste more of the "aftertaste" than the initial. Liver is a good example of this, the initial flavor is meaty and savory, however the slight metallic taste remains for a much longer period than this and the each bite following is similar. There's so many reasons things like is are likely, different chemicals being more soluble or insoluble in saliva, salt is a good example here as it quickly forms is swept away by saliva being water soluble as it is, while other constituents may simply adhere to the tongue and mouth (taste / olfactory / textures). Now something to what you're suggesting is possible, I'm sure, but I don't expect it to be the case for the OPs particular case.
There's just so many factors which I imagine play a role in the whole process, I doubt it relies on any specific one wholly.
Hi, winemaking student here, a bit hazy as I have been busy studying for other subjects lately, but I remember a bit about a lecture on this.
The gist of it is that yes, enzymes in saliva can break down parts of the food you are eating and change the flavour of it in your mouth, however some other compounds can exhibit various flavours depending on the pH of their environment.
A good example of this is "mousiness" which comes from a few chemicals that can be produced during malolactic fermentation. While the wine is still in your mouth it is hard to perceive, however once it is swallowed and enters your very acidic stomach environment the change of flavour becomes more apparent and you find yourself with what tastes like mice or mouse cages in the back of your throat.
I imagine there may be a bunch of other foods that have similar reasons for a change to aftertaste. It is also important to note that taste perception changes depending on concentration of the chemical inducing a flavour sensation. The same compound at different levels of binding to flavour receptors can have different flavours, so you could consider that as you decrease the concentration of the compound it may change your perception of the flavour in this manner.
Or I am talking out my ass, got me this far through uni.