spiciness

Spiciness, or heat, is a sensory attribute of foods and beverages that evokes a burning, sharp, or tingling sensation in the mouth. It arises from chemical compounds that stimulate nerve receptors in the oral mucosa, rather than from taste alone. The perceived intensity depends on concentration, chemical structure, temperature, and the eater’s tolerance and experience.

The most familiar source is capsaicin, a capsaicinoid found in chili peppers, along with related compounds such as dihydrocapsaicin. Other pungent substances include piperine in black pepper and allyl isothiocyanate in mustard and horseradish. Capsaicin activates the TRPV1 receptor, which mediates heat perception; different compounds can provoke distinct sensations, such as sharp burn or lasting warmth.

Measurement of spiciness is commonly expressed on the Scoville scale, originally based on dilution tests and now often reported in Scoville Heat Units (SHU) derived from chemical analysis. Values range from mild (a few tens of SHU) to extremely hot peppers exceeding two million SHU. The scale is a proxy, as perception varies with food matrix, temperature, and individual sensitivity.

Culinary traditions across the world use varying levels of spiciness to balance flavors, texture, and aroma. Cultural preference and exposure influence tolerance and enjoyment, with some cuisines relying on capsaicin to enhance perceived freshness and depth.

Health, safety, and non-culinary uses: Capsaicin can irritate skin and mucous membranes and should be handled with care. It has medicinal applications in topical analgesics and nasal sprays. In sensitive individuals, spicy foods may aggravate gastritis, ulcers, or reflux.