Why does stevia sometimes taste bitter or like liquorice, and how can I avoid it?

Steviol glycosides, especially stevioside, activate both sweet and bitter receptors on the tongue. At low concentrations the sweet signal dominates; as the dose rises, the bitter/liquorice note becomes noticeable. Sensitivity differs between people, so the threshold is personal. The most reliable way to avoid the aftertaste is to under-dose slightly and build up: start with a knife-tip amount per cup, taste, and add only if needed. In cold drinks the powder dissolves more slowly, so stir thoroughly and wait 30 seconds before judging sweetness. Combining stevia with a tiny pinch of salt or a splash of vanilla extract can mask bitterness in baked goods. If you consistently find the taste unpleasant even at minimal doses, you may simply be a high-sensitivity taster — in that case a blend of stevia with erythritol or monk fruit often reads cleaner.