-- Shares Facebook Twitter Reddit Email This article was originally published on The Conversation . Spicy foods taste spicy because they contain a family of compounds called capsaicinoids. Capsaicin is the major culprit.

It's found in chillies, jalapeños, cayenne pepper, and is even the active ingredient in pepper spray . Capsaicin doesn't actually physically heat up your mouth. The burning sensation comes from receptors in the mouth reacting to capsaicin and sending a signal to the brain that something is very hot.

That's why the "hot" chilli sensation feels so real – we even respond by sweating. To alleviate the heat, you need to remove the capsaicin from your mouth. So why doesn't drinking water help make that spicy feeling go away? And what would work better instead? Water-loving and water-hating molecules To help us choose what might wash the capsaicin away most effectively, it's helpful to know that capsaicin is a hydrophobic molecule.

That means it hates being in contact with water and will not easily mix with it. Look what happens when you try to mix hydrophobic sand with water. On the other hand, hydrophilic molecules love water and are very happy to mix with it.

You've likely seen this before. You can easily dissolve hydrophilic sugar in water, but it's hard to wash away hydrophobic oils from your pan using tap water alone. If you try to wash hydrophobic capsaicin away with water, it won't be very effective, because hydrophilic and hydrophobic substances don't m.