Is it normal for apple cider vinegar to irritate the throat?
Under normal circumstances, a mild spicy sensation caused by the acidity of apple cider vinegar is considered normal. However, if the burning sensation is intense or accompanied by discomfort, it may indicate an abnormal reaction. If in doubt, it is advisable to consult a healthcare professional promptly. Detailed analysis is as follows:

If apple cider vinegar is consumed undiluted or at high concentration, the acetic acid it contains can directly irritate the mucous membranes of the throat, causing a brief, mild burning sensation. This type of reaction is normal. Diluting the vinegar (for example, mixing one part vinegar with ten parts water) significantly reduces the burning sensation and should not cause other discomfort, so there is generally no need for excessive concern.
If a strong burning sensation persists even after dilution, or if it is accompanied by sore throat, prolonged burning, or even difficulty swallowing, this is considered abnormal. It may indicate pre-existing damage or inflammation of the throat's mucous membranes, or sensitivity to components in apple cider vinegar. In such cases, acetic acid can exacerbate existing symptoms, and consumption should be stopped immediately while monitoring symptoms.
Apple cider vinegar should always be adequately diluted before regular consumption, and should not be taken on an empty stomach. If unusual burning or discomfort occurs, stop using it immediately. If symptoms persist, seek medical attention promptly to evaluate throat health before deciding whether to continue consumption.