Where heat comes from

Heat is chemistry, not flavor, and it behaves differently from everything else in your sauce.

One compound, mostly

Capsaicin and a handful of related capsaicinoids. They bind to a receptor that also responds to physical heat, which is why the brain reports burning from a cold sauce. Nothing is being damaged.

The compounds are oil soluble and not water soluble. That is why water does not help and dairy does, and it is also why an oil-based product carries heat further and faster through a dish than a vinegar one.

It lives in the placenta, not the seeds

The white pith the seeds attach to holds most of it. Seeds are merely in contact with it. Removing seeds and leaving pith changes little; removing pith and leaving seeds drops the heat sharply.

So deseeding as a heat control is largely folklore, and it costs you time. If you want less heat, take out the pith or use less pepper.

Why it burns and then stops

Receptors desensitize. A taster halfway through a flight is not tasting what the first taster tasted, which matters when you are dialing in a recipe by committee.

Judge heat at the start of a session, on a neutral palate, with breaks. Your own tolerance also climbs across a season of making sauce, which is how producers gradually drift hotter without noticing.

What it does to your process

Capsaicin is stable. It survives cooking, fermentation and time, so heat does not cook off the way aromatics do. A sauce that is too hot at the bench stays too hot.

It also transfers to skin, gloves, cloths and equipment, and stays there. That is a handling question rather than a flavor one, and it is the reason a batch of mild sauce made after a hot one is not mild.

References