Sour, tangy, tart
Vinegar is the product of a two stage fermentation process. The first stage is the making of alcohol from sugars in the form of malted grains, rice, sugar cane or fruits. The results of this first step will determine the final type of vinegar created, this is why we think of wine vinegars, malt vinegar, and indeed, apple cider vineger.
Similar to the frequent occurrence of lactic acid bacteria (the bacteria harnessed to create sauerkraut and kimchi) in our environment, a group of bacteria know as acetic acid bacteria are also found all around us. They have a very particular fermentation function, consuming the ethanol in the alcohol and producing acetic acid as a byproduct. This is what makes vinegar taste sour and tangy, makes it a great natural preservative and a fantastic culinary ingredient.
In the UK, and in the South West of England in particular, we are blessed with fine apple orchards creating some of the world's best apples, and consequently apple cider. This is important, after the acetic acid bacteria have finished turning all the ethanol into acetic acid, the remaining ingredients are what make up the particular characteristics of a vinegar. That means that when our organic unpasteurised apple cider vingegar is bottled, we know it's a powerful combination of naturally occurring acetic acid bacteria ('The mother', more on this later...) and organic UK apples grown in Suffolk.