bitter

Bitter is one of the five basic tastes, alongside sweet, salty, sour, and umami. This taste sensation is often described as acrid and disagreeable. Many different chemical compounds can elicit a bitter taste, including alkaloids like quinine, caffeine, and strychnine. These substances often have very low taste thresholds, meaning they can be detected in weak concentrations. The size of a molecule can influence whether it tastes bitter; larger molecules tend to be more bitter. Some individuals have a genetic inability to taste certain bitter compounds, such as phenylthiocarbamide (PTC). Bitter flavors are also used as "bittering agents" to impart a bitter taste to substances like beer or even to deter consumption of harmful products.1234