Why are hot peppers hot and what will cool my mouth after eating them?

Hot peppers contain a group of chemical substances called capsaicins which
provide the pungency or “heat” that burns your mouth. The degree of
pungency depends on a number of factors
– variety of pepper (Habenero is acknowledged to be the hottest)
– degree of maturity (more mature peppers of the same variety are
hotter)
– growing conditions (lots of sunlight and high temperatures result in
hotter peppers)
– the portion of the pepper that you are eating (the inner layer of the
pepper pod is hotter than the outer flesh which usually provides
the flavors).

There is also a difference in how the pepper affects the person eating it,
depending on which particular capsaicin(s) is in the type of pepper being
eaten. Responses can be immediate, delayed or prolonged and affect the
lips, middle of the tongue, the throat, the back of the mouth. The reason
for this variation is because of the differences in the capsaicins; because
of their structure, they hook on to different areas of the oral cavity and
they react to the nerves in your mouth differently.

What is best to “cool” the pungent sensation in your mouth? Water gives
immediate, but very brief, relief when it flushes away the free capsaicins
but leaves those that are hooked on to your taste/nerve receptors. But then
the hot sensation can actually feel more intense because the water rinses
away the other foodstuffs that had been diluting the effects of the
capsaicins. Starch foods, such as breads, mechanically remove some of the
capsaicins so they can help to reduce the pungency. But if you stop to
think about some very pungently hot ethnic dishes, you will notice that
most are served with sour cream or yogurt or other dairy product.
Traditionally, a few bites of the spicy hot food would be followed by a bit
of the cleansing dairy product. That way, the heat element can be enjoyed
and the other flavor notes within the food can follow. It is thought to be
the protein – casein – in dairy products which detaches the capsaicins from
your receptors and provides some relief.

If no dairy product is handy when you are in the mood for some hot peppers,
an alternative is to eat more peppers. Your nerve receptors will become
numb – after awhile!